ifcopenshell.util.element: dedupe SET-typed attributes in replace_attribute

replace_attribute() rewrites references inside aggregate attributes via
element.walk(), but never checked whether the replacement value was
already present elsewhere in the same aggregate. For an EXPRESS SET
(e.g. IfcProject.RepresentationContexts, IfcRelAggregates.RelatedObjects)
this can leave the same reference listed twice, which is invalid IFC.
LIST and BAG aggregates legitimately allow duplicates, so a blanket dedup
would be wrong; only SET-typed attributes are deduplicated, determined at
runtime from the schema declaration (IfcOpenShell#8706 review comment).

The SET/LIST/BAG check is cached per (schema, class, attribute index), and
the dedup pass itself only runs when a cheap linear pre-check finds the
replacement value already present in the aggregate, so the common case
(no duplicate produced) pays only that pre-check, not a hash-set rebuild.
Benchmarked against a 23MB (431k entities) and a 104MB (2.4M entities) IFC
model against a large SET attribute: worst case adds well under 1ms per
call; the realistic case (merging duplicate contexts, matching the PR
#8706 scenario) shows no measurable regression.

Fixes the root cause flagged in IfcOpenShell#8706 (Moult), obviating the
need for MergeDuplicateContexts' own manual aggregate-dedup pass for that
scenario.

Generated with the assistance of an AI coding tool.

.github/workflows/ci-bonsai-daily.yml

@@ -109,7 +109,7 @@ jobs:
           # Ensure Bonsai and ifcsverchok enable/disable works before uploading to extensions repo.
 
           # Download Blender.
-          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.1/blender-5.1.0-linux-x64.tar.xz
+          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.2/blender-5.2.0-linux-x64.tar.xz
           tar -xf blender.tar.xz
 
           # Setup Blender.
@@ -179,8 +179,7 @@ jobs:
           blender --online-mode --command extension install --enable --sync sun_position
 
           cd IfcOpenShell/src/bonsai
-          pip install pytest-blender
-          pip install pytest-bdd
+          pip install -r requirements-dev.txt
           blender --background --python scripts/setup_pytest.py
           blender --python-expr "import bonsai; print(bonsai.bbim_semver); import ifcopenshell; print(ifcopenshell.version)" --background
           make test

.github/workflows/ci-lint.yaml

@@ -27,10 +27,7 @@ jobs:
       - name: Install dependencies
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh
-          uv tool install ruff
-          uv tool install black
-          uv tool install poethepoet
-          uv tool install ty==0.0.34
+          cat requirements-tools.txt | xargs -L1 uv tool install
 
       # black doesn't catch all syntax errors, so we check them explicitly.
       - name: Check syntax errors
@@ -58,11 +55,17 @@ jobs:
           black --diff --check . | black-codeclimate | python .github/workflows/black_to_github_annotations.py
         continue-on-error: true
 
-      - name: ty check
-        id: ty
-        run: |
-          poe ty-venv
-          poe ty
+      - name: ty check (venv setup)
+        run: poe ty-venv
+
+      - name: ty check (bonsai)
+        id: ty-bonsai
+        run: poe ty-bonsai
+        continue-on-error: true
+
+      - name: ty check (ios)
+        id: ty-ios
+        run: poe ty-ios
         continue-on-error: true
 
       - name: Ruff check
@@ -112,7 +115,10 @@ jobs:
           if [ "${{ steps.ruff.outcome }}" != "success" ]; then
             echo "::error::Ruff check failed, see Summary or 'ruff' step for the details." && ERROR=1
           fi
-          if [ "${{ steps.ty.outcome }}" != "success" ]; then
-            echo "::error::ty check failed, see 'ty check' step for the details." && ERROR=1
+          if [ "${{ steps.ty-bonsai.outcome }}" != "success" ]; then
+            echo "::error::ty check (bonsai) failed, see 'ty check (bonsai)' step for the details." && ERROR=1
+          fi
+          if [ "${{ steps.ty-ios.outcome }}" != "success" ]; then
+            echo "::error::ty check (ios) failed, see 'ty check (ios)' step for the details." && ERROR=1
           fi
           exit $ERROR

.gitignore

@@ -24,6 +24,7 @@
 __pycache__
 *.py.bak
 venv
+uv.lock
 
 # Visual Studio Code files
 .vscode

README.md

@@ -18,7 +18,7 @@ and many other libraries, CLI apps, and more. Support is also provided for auxil
 
 For more information, see:
 
-* [IfcOpenShell Website](http://ifcopenshell.org)
+* [IfcOpenShell Website](https://ifcopenshell.org)
 * [IfcOpenShell Documentation](https://docs.ifcopenshell.org)
   * [IfcOpenShell C++ Installation](https://docs.ifcopenshell.org/ifcopenshell/installation.html)
   * [IfcOpenShell Python Installation](https://docs.ifcopenshell.org/ifcopenshell-python/installation.html)

cmake/CMakeLists.txt

@@ -563,8 +563,8 @@ if(COMPILE_SCHEMA)
     # Bootstrap the parser
     message(STATUS "Compiling schema, this will take a while...")
     execute_process(
-        COMMAND ${PYTHON_EXECUTABLE} bootstrap.py express.bnf
-        WORKING_DIRECTORY ../src/ifcexpressparser
+        COMMAND ${PYTHON_EXECUTABLE} bootstrap.py
+        WORKING_DIRECTORY ../src/ifcopenshell-python/ifcopenshell/express
         OUTPUT_FILE express_parser.py
         RESULT_VARIABLE SUCCESS
     )
@@ -575,7 +575,7 @@ if(COMPILE_SCHEMA)
 
     # Generate code
     execute_process(
-        COMMAND ${PYTHON_EXECUTABLE} ../ifcexpressparser/express_parser.py ../../${COMPILE_SCHEMA}
+        COMMAND ${PYTHON_EXECUTABLE} ../ifcopenshell-python/ifcopenshell/express/express_parser.py ../../${COMPILE_SCHEMA}
         WORKING_DIRECTORY ../src/ifcparse
         OUTPUT_VARIABLE COMPILED_SCHEMA_NAME
     )

nix/build-all.py

@@ -50,7 +50,7 @@ Used environment variables:
     - ``NO_CLEAN`` - do not clean `ifcopenshell` build directories but continue working on current build
     (installed dependencies are never cleared).
     By default option is disabled, to enable pass any value from `1`, `on`, `true`.
-    - ``IFCOS_SCHEMAS`` - schemas to be built; defaults to cmake default (IFC2X3; IFC4; IFC4X3_ADD2) - to be supplied as `2x3;4`
+    - ``IFCOS_SCHEMAS`` - schemas to be built; defaults to cmake default (8 schemas), to be supplied as `2x3;4;4x3_add2`
     - ``USE_OCCT`` - whether to use official Open CASCADE instead of Community Edition
     (`true` by default, any other value is considered `false`)
     - ``WASM_PYTHON_PATH`` - path to WASM Python installation,
@@ -155,7 +155,7 @@ MPFR_VERSION = "3.1.6"  # latest is 4.1.0
 CGAL_VERSION = "v5.6.3"
 USD_VERSION = "23.05"
 TBB_VERSION = "2021.9.0"
-ROCKSDB_VERSION = "9.11.2"
+ROCKSDB_VERSION = "10.4.2"
 ZSTD_VERSION = "1.5.7"
 # binaries
 cp = "cp"
@@ -627,9 +627,10 @@ def build_dependency(
     build_tool_args: "list[str]",
     download_url: str,
     download_name: str,
+    *,
     download_tool: Literal["py", "git"] = download_tool_default,
     revision: "Union[str, None]" = None,
-    patch: "Union[str, list[str], None]" = None,
+    patch: list[str] | None = None,
     shell=None,
     pre_compile_subs: "Sequence[tuple[str, str, str]]" = (),
     additional_files: "Union[dict[str, str], None]" = None,
@@ -714,8 +715,6 @@ def build_dependency(
                 urlretrieve(url, os.path.join(extract_dir, path))
 
     if patch is not None:
-        if isinstance(patch, str):
-            patch = [patch]
         for p in patch:
             patch_abs = (SCRIPT_PATH / p).absolute().__str__()
             if os.path.exists(patch_abs):
@@ -724,6 +723,8 @@ def build_dependency(
                 except Exception as e:
                     # Assert that the patch has already been applied
                     run(["patch", "-p1", "--batch", "--reverse", "--dry-run", "-i", patch_abs], cwd=extract_dir)
+            else:
+                raise FileNotFoundError(patch_abs)
 
     if shell is not None:
         sp.run(shell, shell=True, check=True, cwd=extract_dir)
@@ -1171,6 +1172,14 @@ if "cgal" in targets:
         os.environ["CC"] = MAC_CROSS_COMPILE_INTEL_CC
         gmp_args.extend(MAC_CROSS_COMPILE_INTEL_AUTOCONF_HOST_ARGS)
 
+    # Fixes configure failing to find a working compiler under GCC 15's default -std=gnu23.
+    # Issue presumably will be resolved in any next gmp version, but currently the last one is 6.3.0.
+    # Patch is just applying fix from upstream meantion below:
+    # https://gmplib.org/list-archives/gmp-bugs/2025-February/005561.html
+    gmp_patches = ["./patches/gmp/001-fix-std23.patch"]
+    if GMP_VERSION != "6.3.0":
+        raise Exception(f"GMP_VERSION changed to {GMP_VERSION}, check whether {gmp_patches} is still needed.")
+
     build_dependency(
         name=f"gmp-{GMP_VERSION}",
         mode="autoconf",
@@ -1178,6 +1187,7 @@ if "cgal" in targets:
         pre_compile_subs=(
             [("build/config.h", "HAVE_OBSTACK_VPRINTF 1", "HAVE_OBSTACK_VPRINTF 0")] if "wasm" in flags else []
         ),
+        patch=gmp_patches,
         # Sometimes ftp.gnu.org is very slow, use ftpmirror.gnu.org as a workaround.
         download_url="https://ftpmirror.gnu.org/gnu/gmp/",
         download_name=f"gmp-{GMP_VERSION}.tar.bz2",

nix/cache_dependencies.py

@@ -68,6 +68,7 @@ def unpack_dependencies(install_dir: Path) -> None:
 
 
 if __name__ == "__main__":
+    action = None
     if len(sys.argv) != 2 or (action := sys.argv[1].lower()) not in ("pack", "unpack"):
         print(__doc__)
         sys.exit(1)

nix/patches/gmp/001-fix-std23.patch

@@ -0,0 +1,27 @@
+Fixes configure failing to find a working compiler under GCC 15's default
+-std=gnu23 (upstream fix: https://gmplib.org/repo/gmp/rev/8e7bb4ae7a18).
+
+Upstream fix is patching `acinclude.m4`, but since in the release tarball
+all macros are already expanded to `configure` script, so we're patching
+all occurrences of that macro.
+
+--- a/configure
++++ b/configure
+@@ -6568,7 +6568,7 @@
+
+ #if defined (__GNUC__) && ! defined (__cplusplus)
+ typedef unsigned long long t1;typedef t1*t2;
+-void g(){}
++void g(int,t1 const*,t1,t2,t1 const*,int){}
+ void h(){}
+ static __inline__ t1 e(t2 rp,t2 up,int n,t1 v0)
+ {t1 c,x,r;int i;if(v0){c=1;for(i=1;i<n;i++){x=up[i];r=x+1;rp[i]=r;}}return c;}
+@@ -8187,7 +8187,7 @@
+
+ #if defined (__GNUC__) && ! defined (__cplusplus)
+ typedef unsigned long long t1;typedef t1*t2;
+-void g(){}
++void g(int,t1 const*,t1,t2,t1 const*,int){}
+ void h(){}
+ static __inline__ t1 e(t2 rp,t2 up,int n,t1 v0)
+ {t1 c,x,r;int i;if(v0){c=1;for(i=1;i<n;i++){x=up[i];r=x+1;rp[i]=r;}}return c;}

nix/patches/occt/88af392.patch

@@ -1,32 +0,0 @@
-http://git.dev.opencascade.org/gitweb/?p=occt.git;a=commitdiff;h=0ab4e621833f4eae945a3762c9a29ee12e2eec53#patch1
-diff --git a/src/HLRBRep/HLRBRep_InternalAlgo.cxx b/src/HLRBRep/HLRBRep_InternalAlgo.cxx
-index ca885ca..c13cb06 100644 (file)
---- a/src/HLRBRep/HLRBRep_InternalAlgo.cxx
-+++ b/src/HLRBRep/HLRBRep_InternalAlgo.cxx
-@@ -165,7 +165,7 @@ void HLRBRep_InternalAlgo::Update ()
-       SB.Bounds(v1,v2,e1,e2,f1,f2);
- 
-       for (Standard_Integer e = e1; e <= e2; e++) {
--        HLRBRep_EdgeData ed = aEDataArray.ChangeValue(e);
-+        HLRBRep_EdgeData& ed = aEDataArray.ChangeValue(e);
-         HLRAlgo::DecodeMinMax(ed.MinMax(), TheMin, TheMax);
-        if (FirstTime) {
-          FirstTime = Standard_False;
-@@ -307,7 +307,7 @@ void HLRBRep_InternalAlgo::InitEdgeStatus ()
-   Standard_Integer nf = myDS->NbFaces();
- 
-   for (Standard_Integer e = 1; e <= ne; e++) {
--    HLRBRep_EdgeData ed = aEDataArray.ChangeValue(e);
-+    HLRBRep_EdgeData& ed = aEDataArray.ChangeValue(e);
-     if (ed.Selected()) ed.Status().ShowAll();
-   }
- //  for (Standard_Integer f = 1; f <= nf; f++) {
-@@ -368,7 +368,7 @@ void HLRBRep_InternalAlgo::Select ()
-     Standard_Integer nf = myDS->NbFaces();
-     
-     for (Standard_Integer e = 1; e <= ne; e++) {
--      HLRBRep_EdgeData ed = aEDataArray.ChangeValue(e);
-+      HLRBRep_EdgeData& ed = aEDataArray.ChangeValue(e);
-       ed.Selected(Standard_True);
-     }
-     

nix/patches/pr622.patch

@@ -1,22 +0,0 @@
-From a0deb4ce8b43cf3c8b8c0a4225c6be5296446dbd Mon Sep 17 00:00:00 2001
-From: Adam Eri <adam.eri@blackmirror.media>
-Date: Tue, 3 Sep 2019 23:30:20 +0200
-Subject: [PATCH] Resolves compile error on macOS
-
-Resolves "no member named 'isnan' in namespace 'std'" on macOS
----
- GeneratedSaxParser/src/GeneratedSaxParserUtils.cpp | 1 +
- 1 file changed, 1 insertion(+)
-
-diff --git a/GeneratedSaxParser/src/GeneratedSaxParserUtils.cpp b/GeneratedSaxParser/src/GeneratedSaxParserUtils.cpp
-index 1f9a3eef..dd6f5c59 100644
---- a/GeneratedSaxParser/src/GeneratedSaxParserUtils.cpp
-+++ b/GeneratedSaxParser/src/GeneratedSaxParserUtils.cpp
-@@ -10,6 +10,7 @@
- 
- #include "GeneratedSaxParserUtils.h"
- #include <math.h>
-+#include <cmath>
- #include <memory>
- #include <string.h>
- #include <limits>

pyproject.toml

@@ -1,13 +1,8 @@
 [project]
 name = "IfcOpenShell"
 version = "0.0.0"
-dependencies = [
-    "black==26.3.1",
-    "ruff==0.15.12",
-    "poethepoet",
-    "ty==0.0.32",
-    "gersemi==0.26.1",
-]
+# Don't provide requires-python explicitly
+# allowing pyprojects to set their own (e.g. bonsai and general ifcopenshell version differ).
 
 [tool.black]
 line-length = 120
@@ -43,6 +38,7 @@ exclude = [
 # then they will be inherited by projects' .toml files.
 # This allows using assuming different Python version for different projects.
 [tool.ruff]
+line-length = 120
 exclude = [
     # Submodules.
     "src/ifcopenshell-python/ifcopenshell/express",
@@ -83,92 +79,36 @@ ignore = [
 ]
 
 [tool.ty.rules]
-all = "ignore"
+all = "error"
 
 # Structural rules (no deep type inference needed, easier to adapt).
-abstract-method-in-final-class = "error"
-ambiguous-protocol-member = "error"
-conflicting-declarations = "error"
-conflicting-metaclass = "error"
-cyclic-class-definition = "error"
-cyclic-type-alias-definition = "error"
-dataclass-field-order = "error"
-duplicate-base = "error"
-duplicate-kw-only = "error"
-empty-body = "error"
-escape-character-in-forward-annotation = "error"
-final-on-non-method = "error"
-final-without-value = "error"
-ignore-comment-unknown-rule = "error"
-implicit-concatenated-string-type-annotation = "error"
-inconsistent-mro = "error"
-ineffective-final = "error"
-instance-layout-conflict = "error"
-invalid-dataclass = "error"
-invalid-dataclass-override = "error"
-invalid-enum-member-annotation = "error"
-invalid-explicit-override = "error"
-invalid-frozen-dataclass-subclass = "error"
-invalid-generic-class = "error"
-invalid-generic-enum = "error"
-invalid-ignore-comment = "error"
-invalid-legacy-positional-parameter = "error"
-invalid-legacy-type-variable = "error"
-invalid-named-tuple = "error"
-invalid-newtype = "error"
-invalid-overload = "error"
-invalid-paramspec = "error"
-invalid-protocol = "error"
-invalid-syntax-in-forward-annotation = "error"
-invalid-total-ordering = "error"
-invalid-type-alias-type = "error"
-invalid-type-checking-constant = "error"
-invalid-type-guard-definition = "error"
-invalid-type-variable-bound = "error"
-invalid-type-variable-constraints = "error"
-invalid-typed-dict-header = "error"
-invalid-typed-dict-statement = "error"
-override-of-final-method = "error"
-override-of-final-variable = "error"
-possibly-missing-import = "error"
-possibly-missing-submodule = "error"
-# Has false positives due to ty walrus operator bug.
-# possibly-unresolved-reference = "error"
-raw-string-type-annotation = "error"
-redundant-final-classvar = "error"
-shadowed-type-variable = "error"
-subclass-of-final-class = "error"
-super-call-in-named-tuple-method = "error"
-unavailable-implicit-super-arguments = "error"
-unbound-type-variable = "error"
-undefined-reveal = "error"
-unresolved-global = "error"
-unresolved-import = "error"
-unresolved-reference = "error"
-unused-ignore-comment = "error"
-unused-type-ignore-comment = "error"
-useless-overload-body = "error"
+# Maybe later, requires to specify element types for all generics.
+missing-type-argument = "ignore"
+# Conflicts with `bpy` props defined using annotations.
+invalid-type-form = "ignore"
 
 # Non-structural rules:
-deprecated = "error"
-zero-stepsize-in-slice = "error"
-possibly-missing-implicit-call = "error"
-unused-awaitable = "error"
-
-# Function argument rules:
 # Conflicts with `ifcopenshell.api.geometry.add_representation` type of callables we have, confusing them with a module.
-# call-non-callable = "error"
-conflicting-argument-forms = "error"
+call-non-callable = "ignore"
+# bpy is missing some context manager implementations.
+invalid-context-manager = "ignore"
+# Doesn't go well with `bpy.ops.xxx.yyy`.
+unresolved-attribute = "ignore"
 # Too many false positives.
-# invalid-argument-type = "error"
-missing-argument = "error"
-parameter-already-assigned = "error"
-positional-only-parameter-as-kwarg = "error"
-too-many-positional-arguments = "error"
-unknown-argument = "error"
-# Has a lot of warnings due to current ty walrus operator issues.
-# index-out-of-bounds = "error"
-# unresolved-attribute = "error"
+invalid-argument-type = "ignore"
+invalid-method-override = "ignore"
+invalid-assignment = "ignore"
+invalid-parameter-default = "ignore"
+missing-override-decorator = "ignore"
+invalid-yield = "ignore"
+invalid-return-type = "ignore"
+non-callable-init-subclass = "ignore"
+not-iterable = "ignore"
+possibly-missing-attribute = "ignore"
+no-matching-overload = "ignore"
+not-subscriptable = "ignore"
+unsupported-dynamic-base = "ignore"
+unsupported-operator = "ignore"
 
 [tool.ty.environment]
 extra-paths = [
@@ -215,6 +155,18 @@ exclude = [
 
 [tool.poe.tasks]
 
+dev-setup.sequence = [
+    {cmd = "uv sync"},
+    {cmd = "uv pip install -e ./src/bsdd/"},
+    {cmd = "uv pip install -e ./src/ifcopenshell-python/[advanced,dev]"},
+    {cmd = "uv pip install -e ./src/ifcedit/"},
+    {cmd = "uv pip install -e ./src/ifcpatch/"},
+    {cmd = "uv pip install -e ./src/ifcquery/"},
+    {cmd = "uv pip install -e './src/ifcmcp/[mcp]'"},
+    {cmd = "uv pip install -r src/bonsai/requirements-dev.txt"},
+]
+dev-setup.help = "Install repo packages in editable mode"
+
 ruff = "ruff check"
 
 black = "black ."
@@ -240,9 +192,9 @@ format.sequence = ["black", "ruff"]
 cmake-format = "gersemi . --in-place"
 
 [tool.poe.tasks.ty-ios]
-# --ignore unresolved-reference: walrus operator false positives in ty.
 cmd = """
     ty check
+    nix/
     src/bcf
     src/bsdd
     src/ifc2ca
@@ -257,7 +209,6 @@ cmd = """
     src/ifcpatch
     src/ifctester
     --python=src/ifcopenshell-python/.venv
-    --ignore unresolved-reference
 """
 
 [tool.poe.tasks.bonsai-deps]

requirements-tools.txt

@@ -0,0 +1,5 @@
+black==26.3.1
+ruff==0.15.22
+poethepoet
+ty==0.0.61
+gersemi==0.26.1

src/bcf/bcf/v3/bcfapi.py

@@ -188,6 +188,8 @@ class BcfClient:
                 response.raise_for_status()
             return response.status_code, response.text
         except requests.exceptions.HTTPError as errh:
+            response = errh.response
+            assert response is not None
             print(f"message: {response.reason}'  '{response.status_code}, {errh}")
             return response.status_code, response.reason
 
@@ -206,6 +208,8 @@ class BcfClient:
                 response.raise_for_status()
             return response.status_code, response.text
         except requests.exceptions.HTTPError as errh:
+            response = errh.response
+            assert response is not None
             print(f"message: {response.reason}'  '{response.status_code}, {errh}")
             return response.status_code, response.reason
 
@@ -222,6 +226,8 @@ class BcfClient:
                 response.raise_for_status()
             return response.status_code, response.text
         except requests.exceptions.HTTPError as errh:
+            response = errh.response
+            assert response is not None
             print(f"message: {response.reason}'  '{response.status_code}, {errh}")
             return response.status_code, response.reason
 

src/bonsai/bonsai/bim/data/assets/default.css

@@ -24,10 +24,28 @@ a text, a tspan {  fill: blue !important;  text-decoration: underline;}
 a:hover { cursor: pointer; }
 .cut { fill: black; stroke: black; stroke-linecap: 'round'; stroke-width: 0.35; fill-rule: evenodd; }
 .projection { fill: white; stroke: black; stroke-linecap: 'round'; stroke-width: 0.25; }
-.surface { stroke: none; fill: #fff; fill-rule: evenodd; }
-.annotation { fill: none; stroke: black; stroke-linecap: 'round'; stroke-width: 0.25; }
-.IfcAnnotation { fill: none; stroke: black; stroke-linecap: 'round'; stroke-width: 0.25; }
-.IfcGeographicElement { fill: none; stroke: black; stroke-linecap: 'round'; stroke-width: 1; }
+/* SVG edge classification (issue #3668): see edge-classification.md. These select directly on
+   the <path> element (each classified projection edge carries its own class), so they win over
+   the inherited .projection rule above regardless of specificity. */
+path.outline { stroke: black; stroke-width: 0.35; stroke-opacity: 1; }
+path.boundary { stroke: black; stroke-width: 0.3; stroke-opacity: 0.9; }
+path.crease { stroke: black; stroke-width: 0.25; stroke-opacity: 0.85; }
+path.sharp { stroke: black; stroke-width: 0.18; stroke-opacity: 0.7; }
+path.flush { stroke: black; stroke-width: 0.1; stroke-opacity: 0.4; }
+
+/* Debug CSS for troubleshooting edge classification */
+/*
+path.outline { stroke: black; stroke-width: 0.35; stroke-opacity: 1; }
+path.boundary { stroke: orange; stroke-width: 0.3; stroke-opacity: 0.9; }
+path.crease { stroke: green; stroke-width: 0.25; stroke-opacity: 0.85; }
+path.sharp { stroke: red; stroke-width: 0.18; stroke-opacity: 0.7; }
+path.flush { stroke: blue; stroke-width: 0.1; stroke-opacity: 0.4; }
+*/
+
+.surface {fill: white; stroke-width: 0.1;}
+.annotation { fill: none; stroke: black; stroke-linecap: 'round'; stroke-width: 0.3; }
+.IfcAnnotation { fill: none; stroke: black; stroke-linecap: 'round'; stroke-width: 0.3; }
+/* .IfcGeographicElement { fill: none; stroke: rgb(150, 150, 150); stroke-linecap: 'round'; stroke-dasharray: 1, 2;} */
 .PredefinedType-LINEWORK { stroke: black; stroke-width: 0.25; }
 .PredefinedType-LINEWORK.dashed { stroke-dasharray: 3, 2; }
 .PredefinedType-LINEWORK.fine { stroke-width: 0.18; stroke: #777777; }

src/bonsai/bonsai/bim/data/pset/EPset_Drawing.ifc

@@ -5,7 +5,7 @@ FILE_NAME('EPset_Drawing.ifc','2020-01-01T00:00:00',$,$,'EPset_Drawing','EPset_D
 FILE_SCHEMA(('IFC4'));
 ENDSEC;
 DATA;
-#1=IFCPROPERTYSETTEMPLATE('2JhNIvqZrFnAgxfhK0XVQX',$,'EPset_Drawing','',.PSET_OCCURRENCEDRIVEN.,'IfcAnnotation/DRAWING',(#23,#22,#27,#24,#29,#30,#19,#12,#26,#9,#8,#7,#6,#4,#18,#11,#5,#20,#25,#14,#10,#17,#28,#16,#3,#21,#13,#15,#2));
+#1=IFCPROPERTYSETTEMPLATE('2JhNIvqZrFnAgxfhK0XVQX',$,'EPset_Drawing','',.PSET_OCCURRENCEDRIVEN.,'IfcAnnotation/DRAWING',(#23,#22,#27,#24,#29,#30,#19,#12,#26,#9,#8,#7,#6,#4,#18,#11,#5,#20,#25,#14,#10,#17,#28,#16,#3,#21,#13,#15,#2,#31,#32,#33,#34,#35,#36,#37));
 #2=IFCSIMPLEPROPERTYTEMPLATE('23JavTMk98ZxXhrUEnjAcf',$,'TargetView','',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
 #3=IFCSIMPLEPROPERTYTEMPLATE('1yVWUt5H9DAOuu0OaMMLpe',$,'Scale','The scale of this drawing represented as a numerator and denominator, such as 1/100',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
 #4=IFCSIMPLEPROPERTYTEMPLATE('3gsuPBtU93b8f0gg1pjkq6',$,'HumanScale','The scale of this drawing in human readable format, such as 1:100',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
@@ -35,5 +35,12 @@ DATA;
 #28=IFCSIMPLEPROPERTYTEMPLATE('1YSnFzurrEyRNtoLdmmddP',$,'BringToFront','The objects with these SVG classes will render in front of all other objects.Ex: IfcBeam, IfcColumn',.P_SINGLEVALUE.,'IfcText',$,$,$,$,$,.READWRITE.);
 #29=IFCSIMPLEPROPERTYTEMPLATE('0lP6Y8q9v2QhDnR4sT7uVx',$,'PerspectiveShiftX','Horizontal perspective camera shift stored as drawing metadata using Blender camera shift units.',.P_SINGLEVALUE.,'IfcReal',$,$,$,$,$,.READWRITE.);
 #30=IFCSIMPLEPROPERTYTEMPLATE('2mR8b1NcW5EoFyG7hJ9kLp',$,'PerspectiveShiftY','Vertical perspective camera shift stored as drawing metadata using Blender camera shift units.',.P_SINGLEVALUE.,'IfcReal',$,$,$,$,$,.READWRITE.);
+#31=IFCSIMPLEPROPERTYTEMPLATE('1cFVJnqT13m8ItkMHaI1tp',$,'UseEdgeClassification','Enable the boundary/outline/sharp/crease/flush SVG edge classification scheme (issue #3668). When false, drawings use the original unclassified linework.',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#32=IFCSIMPLEPROPERTYTEMPLATE('2kB$mxBgnBUvhjh0Ti0c4P',$,'RenderCreases','Whether to render ''crease'' (concave) edges. Only relevant when UseEdgeClassification is enabled.',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#33=IFCSIMPLEPROPERTYTEMPLATE('3MSIJNW$T8r9Hl12kk0BY$',$,'ValleyAngleMinDegrees','Minimum concave dihedral deviation from flat, in degrees, for a projection edge to be classified as ''crease'' rather than ''flush''.',.P_SINGLEVALUE.,'IfcReal',$,$,$,$,$,.READWRITE.);
+#34=IFCSIMPLEPROPERTYTEMPLATE('2epSGfC4bFM9gb1X7zBIp4',$,'RenderSharp','Whether to render ''sharp'' (convex) edges. Only relevant when UseEdgeClassification is enabled.',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#35=IFCSIMPLEPROPERTYTEMPLATE('3TZwsEjkr5WRDKcgrYzSIA',$,'RidgeAngleMinDegrees','Minimum convex dihedral deviation from flat, in degrees, for a projection edge to be classified as ''sharp'' rather than ''flush''.',.P_SINGLEVALUE.,'IfcReal',$,$,$,$,$,.READWRITE.);
+#36=IFCSIMPLEPROPERTYTEMPLATE('2Jua$lO754vgZOkBoHM2gA',$,'RenderFlush','Whether to render ''flush'' edges (dihedral deviation below both ridge/valley thresholds). Only relevant when UseEdgeClassification is enabled.',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#37=IFCSIMPLEPROPERTYTEMPLATE('1zM9sia2L8RQDnWZxgUwlZ',$,'JoinClasses','Comma separated list of IFC classes whose cut linework will be joined together when they meet (e.g. mitred at a corner).\X2\000A\X0\Defaults to ''IfcWall,IfcSlab'' if not set. Override to also join other classes, such as ''IfcWall,IfcSlab,IfcCovering''.',.P_SINGLEVALUE.,'IfcText',$,$,$,$,$,.READWRITE.);
 ENDSEC;
 END-ISO-10303-21;

src/bonsai/bonsai/bim/data/webui/static/js/gantt.js

@@ -244,7 +244,7 @@ function addGanttElement(blenderId, tasks, workSched, filename) {
       vShowTaskInfoLink: 1, // Show link in tool tip (0/1)
       vShowEndWeekDate: 0, // Show/Hide the date for the last day of the week in header for daily
       vUseSingleCell: 10000, // Set the threshold cell per table row (Helps performance for large data.
-      vFormatArr: ["Day", "Week", "Month", "Quarter"], // Even with setUseSingleCell using Hour format on such a large chart can cause issues in some browsers,
+      vFormatArr: ["Hour", "Day", "Week", "Month", "Quarter"], // vUseSingleCell keeps Hour usable on large charts.
       vShowRes: true, // Disable the resource column.
       vShowComp: false, // Disable the completion column.
       vShowDur: false, // Disable the duration column, because jsgantt doesn't calculate durations the way we want.

src/bonsai/bonsai/bim/ifc.py

@@ -46,7 +46,7 @@ IFC_CONNECTED_TYPE = Union[bpy.types.Material, bpy.types.Object]
 class OperationData(TypedDict):
     id: int
     guid: NotRequired[str]
-    obj: str
+    obj: NotRequired[str]
 
 
 class EditObjectOperationData(TypedDict):

src/bonsai/bonsai/bim/import_ifc.py

@@ -1103,12 +1103,14 @@ class IfcImporter:
         vertices = [[v[i], v[i + 1], v[i + 2], 1] for i in range(0, len(v), 3)]
         edges = [[e[i], e[i + 1]] for i in range(0, len(e), 2)]
         v2 = None
+        polyline = None
         for edge in edges:
             v1 = vertices[edge[0]]
             if v1 != v2:
                 polyline = curve.splines.new("POLY")
                 polyline.points[-1].co = mathutils.Vector(v1)
             v2 = vertices[edge[1]]
+            assert polyline is not None
             polyline.points.add(1)
             polyline.points[-1].co = mathutils.Vector(v2)
         edges_item_ids = ifcopenshell.util.shape.get_edges_representation_item_ids(geometry).tolist()

src/bonsai/bonsai/bim/module/boundary/operator.py

@@ -843,7 +843,6 @@ class AddBoundary(bpy.types.Operator, tool.Ifc.Operator):
                         settings = ifcopenshell.geom.settings()
                         shape = ifcopenshell.geom.create_shape(settings, opening)
                         mat = Matrix(ifcopenshell.util.shape.get_shape_matrix(shape))
-                        mat.translation = (0, 0, 0)
                         opening_bm = bmesh.new()
                         verts = ifcopenshell.util.shape.get_vertices(shape.geometry)
                         for vert in verts:
@@ -1060,6 +1059,7 @@ class AddBoundary(bpy.types.Operator, tool.Ifc.Operator):
         return tool.Ifc.get().createIfcConnectionSurfaceGeometry(surface)
 
     def export_surface(self, polygon, target_face_matrix):
+        ifc_file = tool.Ifc.get()
         x_axis = target_face_matrix.col[0][:3]
         z_axis = target_face_matrix.col[2][:3]
         p1 = target_face_matrix.translation
@@ -1072,18 +1072,20 @@ class AddBoundary(bpy.types.Operator, tool.Ifc.Operator):
         placement = builder.create_axis2_placement_3d([o / self.unit_scale for o in p1], z_axis, x_axis)
         surface.BasisSurface = tool.Ifc.get().create_entity("IfcPlane", placement)
 
-        if tool.Ifc.get().schema != "IFC2X3":
+        schema = ifc_file.schema
+        if schema != "IFC2X3":
             points = [tool.Model.convert_si_to_unit(list(co)) for co in polygon.exterior.coords]
             point_list = tool.Ifc.get().createIfcCartesianPointList2D(points)
             outer_boundary = tool.Ifc.get().createIfcIndexedPolyCurve(point_list, None, False)
 
-            inner_boundaries = []
+            inner_boundaries: list[ifcopenshell.entity_instance] = []
             for interior in polygon.interiors:
                 points = [tool.Model.convert_si_to_unit(list(co)) for co in interior.coords]
                 point_list = tool.Ifc.get().createIfcCartesianPointList2D(points)
                 inner_boundaries.append(tool.Ifc.get().createIfcIndexedPolyCurve(point_list, None, False))
         else:
-            pass  # TODO
+            # TODO:
+            raise NotImplementedError(schema)
 
         surface.OuterBoundary = outer_boundary
         surface.InnerBoundaries = inner_boundaries

src/bonsai/bonsai/bim/module/brick/data.py

@@ -156,16 +156,13 @@ class BrickschemaReferencesData:
         for rel in getattr(tool.Ifc.get_entity(bpy.context.active_object), "HasAssociations", []):
             if rel.is_a("IfcRelAssociatesLibrary"):
                 reference = rel.RelatingLibrary
-                if tool.Ifc.get_schema() == "IFC2X3" and "#" not in reference.ItemReference:
-                    continue
-                if tool.Ifc.get_schema() != "IFC2X3" and "#" not in reference.Identification:
+                identification = tool.Document.get_external_reference_id(reference)
+                if not identification or "#" not in identification:
                     continue
                 results.append(
                     {
                         "id": reference.id(),
-                        "identification": (
-                            reference.ItemReference if tool.Ifc.get_schema() == "IFC2X3" else reference.Identification
-                        ),
+                        "identification": identification,
                         "name": reference.Name or "Unnamed",
                     }
                 )

src/bonsai/bonsai/bim/module/cad/operator.py

@@ -400,6 +400,7 @@ class CadOffset(bpy.types.Operator):
         [verts.update(e.verts) for e in edges]
 
         # Use the viewport angle to determine the offset direction
+        wp = None
         for area in bpy.context.screen.areas:
             if area.type == "VIEW_3D":
                 # Don't ask me, I don't know.
@@ -409,6 +410,7 @@ class CadOffset(bpy.types.Operator):
                 z = area.spaces.active.region_3d.view_rotation @ Vector((0, 0, 1))
                 wp = Matrix([x, y, z, Vector((0, 0, 0))]).to_4x4().transposed()
                 break
+        assert wp is not None
 
         rotation = Matrix.Rotation(pi / 2, 2, "Z")
         rotation_i = Matrix.Rotation(-pi / 2, 2, "Z")

src/bonsai/bonsai/bim/module/classification/operator.py

@@ -478,6 +478,7 @@ class ChangeClassificationLevel(bpy.types.Operator):
     def execute(self, context):
         props = tool.Classification.get_classification_props()
         props.available_library_references.clear()
+        reference = None
         for reference in IfcStore.classification_file.by_id(self.parent_id).HasReferences:
             new = props.available_library_references.add()
             new.identification = reference.Identification or ""
@@ -485,6 +486,7 @@ class ChangeClassificationLevel(bpy.types.Operator):
             new.ifc_definition_id = reference.id()
             new.has_references = bool(reference.HasReferences)
             new.referenced_source
+        assert reference
         if reference.ReferencedSource.is_a("IfcClassificationReference"):
             props.active_library_referenced_source = reference.ReferencedSource.ReferencedSource.id()
         else:

src/bonsai/bonsai/bim/module/cost/data.py

@@ -156,6 +156,8 @@ class CostSchedulesData:
             values = root_element.CostValues
         elif root_element.is_a("IfcConstructionResource"):
             values = root_element.BaseCosts
+        else:
+            assert False, root_element
         for cost_value in values or []:
             cls._load_cost_value(root_element, data, cost_value)
             # data["CostValues"].append(cost_value.id())

src/bonsai/bonsai/bim/module/document/data.py

@@ -127,36 +127,25 @@ class ObjectDocumentData:
                 identification = None
 
                 if is_information:
-                    if tool.Ifc.get_schema() == "IFC2X3":
-                        identification = relating_document.DocumentId
-                    else:
-                        identification = relating_document.Identification
+                    identification = tool.Document.get_document_information_id(relating_document)
 
                     location = getattr(relating_document, "Location", None)
                     description = getattr(relating_document, "Description", "No description")
                 else:
                     description = relating_document.Description
-                    if tool.Ifc.get_schema() == "IFC2X3":
-                        reference_to_document = relating_document.ReferenceToDocument
-                        if not name and reference_to_document:
-                            name = reference_to_document[0].Name
+                    referenced_document = tool.Document.get_reference_document(relating_document)
 
-                        identification = relating_document.ItemReference
-                        if not identification and reference_to_document:
-                            identification = reference_to_document[0].DocumentId
-                        location = relating_document.Location
-                    else:
-                        referenced_document = relating_document.ReferencedDocument
-                        if not name and referenced_document:
-                            name = referenced_document.Name
+                    if not name and referenced_document:
+                        name = referenced_document.Name
 
-                        identification = relating_document.Identification
-                        if not identification and referenced_document:
-                            identification = referenced_document.Identification
+                    identification = tool.Document.get_external_reference_id(relating_document)
+                    if not identification and referenced_document:
+                        identification = tool.Document.get_document_information_id(referenced_document)
 
-                        location = relating_document.Location
-                        if location is None and referenced_document:
-                            location = referenced_document.Location
+                    location = relating_document.Location
+                    # IFC2X3 IfcDocumentInformation has no Location to fall back to.
+                    if location is None and referenced_document and tool.Ifc.get_schema() != "IFC2X3":
+                        location = referenced_document.Location
 
                 location = cls.convert_to_file_uri(location) if location else None
 

src/bonsai/bonsai/bim/module/drawing/__init__.py

@@ -47,6 +47,7 @@ classes = (
     operator.CleanWireframes,
     operator.ContractSheet,
     operator.ConvertSVGToDXF,
+    operator.CopyAnnotationToDrawing,
     operator.CopyTextToSelection,
     operator.CreateDrawing,
     operator.CreateSheets,

src/bonsai/bonsai/bim/module/drawing/decoration.py

@@ -425,10 +425,12 @@ class BaseDecorator:
 
         blf.size(font_id, font_size_px)
 
+        w, h = None, None
         if box_alignment or center or vcenter:
             w, h = blf.dimensions(font_id, text)
 
         if box_alignment:
+            assert w is not None and h is not None
             box_alignment_offset = Vector((0, 0))
             if "bottom" in box_alignment:
                 pass
@@ -450,10 +452,12 @@ class BaseDecorator:
         else:
             # horizontal centering
             if center:
+                assert w is not None
                 pos -= Vector((cos, sin)) * w * 0.5
 
             # vertical centering
             if vcenter:
+                assert h is not None
                 pos -= Vector((-sin, cos)) * h * 0.5
 
             # side-shifting
@@ -1001,6 +1005,8 @@ class FallDecorator(BaseDecorator):
             O = A.copy()
             O.z = B.z
             run = (B - O).length
+
+            angle_tg = None
             if run != 0:
                 angle_tg = rise / run
                 angle = round(degrees(atan(angle_tg)))
@@ -1018,6 +1024,7 @@ class FallDecorator(BaseDecorator):
             elif object_type == "SLOPE_PERCENT":
                 if angle == 90:
                     return "-"
+                assert angle_tg is not None
                 return f"{round(angle_tg * 100)} %"
             return "NO DATA"
 
@@ -1249,6 +1256,7 @@ class SectionLevelDecorator(BaseDecorator):
         }
 
         # process edges
+        text_position, text_dir = None, None
         for edge in edges_original:
             v0, v1 = winspace_verts[edge[0]], winspace_verts[edge[1]]
             start_i = len(output_verts)
@@ -1554,32 +1562,39 @@ class SectionDecorator(BaseDecorator):
             v0, v1 = winspace_verts[edge[0]], winspace_verts[edge[1]]
             start_i = len(output_verts)
 
+            circle_head = None
             if display_start_circle or display_end_circle:
                 circle_head = get_circle_head(circle_size)
 
-            if display_start_symbol or display_end_symbol or connect_markers:
+            triangle_head, divider_offset, edge_dir_circle = None, None, None
+            display_symbol = display_start_symbol or display_end_symbol
+            if display_symbol or connect_markers:
                 edge_dir = (v1 - v0).normalized()
                 side = (edge_dir.yx * Vector((1, -1))).to_3d()
                 edge_dir_circle = edge_dir * circle_size
 
-            if display_start_symbol or display_end_symbol:
-                triangle_head = get_triangle_head(edge_dir, -side, triangle_length, triangle_width)
-                divider_offset = []
-                divider_offset.append(edge_dir_circle if connect_markers else edge_dir_circle * 3)
-                divider_offset.append(edge_dir_circle)
+                if display_symbol:
+                    triangle_head = get_triangle_head(edge_dir, -side, triangle_length, triangle_width)
+                    divider_offset = []
+                    divider_offset.append(edge_dir_circle if connect_markers else edge_dir_circle * 3)
+                    divider_offset.append(edge_dir_circle)
 
             if display_start_circle:
+                assert circle_head is not None
                 start_i = add_verts_sequence([v + v0 for v in circle_head], start_i, **out_kwargs, closed=True)
                 # circle middle divider
                 if not display_start_symbol:
+                    assert divider_offset is not None
                     start_i = add_verts_sequence(
                         [v0 + divider_offset[0], v0 - divider_offset[1]], start_i, **out_kwargs
                     )
 
             if display_start_symbol:
+                assert triangle_head is not None
                 start_i = add_verts_sequence([v + v0 for v in triangle_head], start_i, **out_kwargs, closed=True)
 
             if display_end_circle:
+                assert circle_head is not None
                 start_i = add_verts_sequence([v + v1 for v in circle_head], start_i, **out_kwargs, closed=True)
                 # circle middle divider
                 if not display_end_symbol:
@@ -1588,9 +1603,11 @@ class SectionDecorator(BaseDecorator):
                     )
 
             if display_end_symbol:
+                assert triangle_head is not None
                 start_i = add_verts_sequence([v + v1 for v in triangle_head], start_i, **out_kwargs, closed=True)
 
             if connect_markers:
+                assert edge_dir_circle is not None
                 gap = []
                 gap.append(edge_dir_circle if display_start_symbol else Vector((0, 0, 0)))
                 gap.append(edge_dir_circle if display_end_symbol else Vector((0, 0, 0)))
@@ -1677,6 +1694,12 @@ class CutDecorator:
         selected_elements_color = self.addon_prefs.decorator_color_selected
         self.fallback_colour = (0.3, 0.3, 0.3, 1)
 
+        # Evaluate camera movement once per redraw rather than twice per object: is_camera_moved()
+        # runs eval()/numpy on the camera matrix and, as a side effect, refreshes the stored
+        # checksum on the first True result - so calling it per object also made the second call
+        # (fill) see an already-updated checksum and skip recalculating when it shouldn't.
+        self.camera_moved = self.is_camera_moved()
+
         all_vertices = []
         all_edges = []
         selected_vertices = []
@@ -1802,23 +1825,35 @@ class CutDecorator:
 
         # Currently selected objects must be recalculated as they may be being moved / edited.
         # If the camera is selected, we also recalculate as the user may be moving the camera.
+        is_selected = obj.select_get()
+        recalc_cut = not has_cut_cache or is_selected or self.camera_moved
+        recalc_fill = not has_fill_cache or is_selected or self.camera_moved
+        if not (recalc_cut or recalc_fill):
+            return
 
-        if not has_cut_cache or obj.select_get() or self.is_camera_moved():
-            self.recalculate_cut(context, obj, element)
-        if not has_fill_cache or obj.select_get() or self.is_camera_moved():
-            self.recalculate_fill(context, obj, element)
+        # The intersection test builds a bmesh and scans every vertex; both recalculations need
+        # the same answer, so compute it once here rather than once in each.
+        is_intersecting = tool.Drawing.is_intersecting_camera(obj, context.scene.camera)
+        if recalc_cut:
+            self.recalculate_cut(context, obj, element, is_intersecting)
+        if recalc_fill:
+            self.recalculate_fill(context, obj, element, is_intersecting)
 
-    def recalculate_cut(self, context, obj: bpy.types.Object, element: ifcopenshell.entity_instance) -> None:
-        if tool.Drawing.is_intersecting_camera(obj, context.scene.camera):
+    def recalculate_cut(
+        self, context, obj: bpy.types.Object, element: ifcopenshell.entity_instance, is_intersecting: bool
+    ) -> None:
+        if is_intersecting:
             verts, edges = tool.Drawing.bisect_mesh(obj, context.scene.camera)
             DecoratorData.cut_cache[element.id()] = (verts, edges)
         else:
             DecoratorData.cut_cache[element.id()] = (False, False)
 
-    def recalculate_fill(self, context, obj: bpy.types.Object, element: ifcopenshell.entity_instance) -> None:
+    def recalculate_fill(
+        self, context, obj: bpy.types.Object, element: ifcopenshell.entity_instance, is_intersecting: bool
+    ) -> None:
         element_id = element.id()
 
-        if not tool.Drawing.is_intersecting_camera(obj, context.scene.camera):
+        if not is_intersecting:
             DecoratorData.fill_cache[element_id] = {}
             return
 
@@ -1871,6 +1906,8 @@ class CutDecorator:
             layer_set = material
             offset = 0
             sense_factor = 1
+        else:
+            assert False, material
 
         if len(layer_set.MaterialLayers) == 1:
             material = layer_set.MaterialLayers[0].Material
@@ -1897,6 +1934,8 @@ class CutDecorator:
             co = Vector((0.0, 0.0, offset))
             no = tool.Drawing.get_extrusion_vector(element).normalized()
             no = Vector([1.0, 0.0, 0.0])
+        else:
+            assert False, usage
         no *= sense_factor
         last_i = len(layer_set.MaterialLayers) - 1
 

src/bonsai/bonsai/bim/module/drawing/helper.py

@@ -225,9 +225,11 @@ def format_distance(
             unit_system, unit_length, unit_fraction = unit_mapping[custom_unit]
 
     value *= unit_scale
+    tx_dist = None
 
     # Imperial Formatting
     if unit_system == "IMPERIAL":
+        toInches = None
         if in_unit_length:
             if unit_length == "INCHES":
                 toInches = 1
@@ -241,6 +243,7 @@ def format_distance(
             toInches = 1550
             inPerFoot = 144
 
+        assert toInches is not None
         decInches = value * toInches
         decFeet = decInches / 12
 
@@ -383,6 +386,7 @@ def format_distance(
         if precision and isinstance(precision, float):
             value = precision * round(float(value) / precision)
 
+        fmt = None
         if decimal_places is not None:
             fmt = "%1." + str(decimal_places) + "f"
 
@@ -465,6 +469,7 @@ def format_distance(
         assert f"Unexpected unit_system - '{unit_system}'."
         # tx_dist = fmt % value
 
+    assert tx_dist is not None
     return tx_dist
 
 

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -228,6 +228,90 @@ class DuplicateDrawing(bpy.types.Operator, tool.Ifc.Operator):
         )
 
 
+def get_copy_annotation_target_drawings(self, context):
+    global COPY_ANNOTATION_TARGET_DRAWINGS_ENUM
+    drawings = [e for e in tool.Ifc.get().by_type("IfcAnnotation") if e.ObjectType == "DRAWING"]
+    drawings.sort(key=lambda d: d.Name or "")
+    COPY_ANNOTATION_TARGET_DRAWINGS_ENUM = [(str(d.id()), d.Name or "Unnamed", "") for d in drawings]
+    return COPY_ANNOTATION_TARGET_DRAWINGS_ENUM
+
+
+COPY_ANNOTATION_TARGET_DRAWINGS_ENUM = []
+
+
+class CopyAnnotationToDrawing(bpy.types.Operator, tool.Ifc.Operator):
+    bl_idname = "bim.copy_annotation_to_drawing"
+    bl_label = "Copy Annotation To Drawing"
+    bl_description = (
+        "Copy the selected annotations to another drawing.\n\n"
+        "The copies become independent annotations assigned to the chosen drawing, "
+        "placed in its view plane. The originals stay in their current drawing"
+    )
+    bl_options = {"REGISTER", "UNDO"}
+    target_drawing: bpy.props.EnumProperty(name="Target Drawing", items=get_copy_annotation_target_drawings)
+
+    if TYPE_CHECKING:
+        target_drawing: str
+
+    @classmethod
+    def poll(cls, context):
+        if not tool.Ifc.get():
+            cls.poll_message_set("No IFC project loaded.")
+            return False
+        if not cls.get_selected_annotations(context):
+            cls.poll_message_set("No annotation selected.")
+            return False
+        return True
+
+    @classmethod
+    def get_selected_annotations(cls, context) -> list[ifcopenshell.entity_instance]:
+        return [
+            element
+            for obj in context.selected_objects
+            if (element := tool.Ifc.get_entity(obj))
+            and element.is_a("IfcAnnotation")
+            and element.ObjectType != "DRAWING"
+        ]
+
+    def invoke(self, context, event):
+        assert context.window_manager
+        return context.window_manager.invoke_props_dialog(self)
+
+    def draw(self, context):
+        assert self.layout
+        row = self.layout.row()
+        row.prop(self, "target_drawing")
+
+    def _execute(self, context):
+        if not self.target_drawing:
+            self.report({"ERROR"}, "No target drawing selected.")
+            return {"CANCELLED"}
+        target_drawing = tool.Ifc.get().by_id(int(self.target_drawing))
+        annotations = self.get_selected_annotations(context)
+        previous_selection = [obj for a in annotations if (obj := tool.Ifc.get_object(a))]
+        previous_active = context.view_layer.objects.active
+        copied = core.copy_annotations_to_drawing(
+            tool.Ifc,
+            tool.Collector,
+            tool.Drawing,
+            tool.Geometry,
+            annotations=annotations,
+            target_drawing=target_drawing,
+        )
+        for obj in context.selected_objects:
+            obj.select_set(False)
+        for obj in previous_selection:
+            if obj.name in context.view_layer.objects:
+                obj.select_set(True)
+        if previous_active and previous_active.name in context.view_layer.objects:
+            context.view_layer.objects.active = previous_active
+        skipped = len(annotations) - len(copied)
+        message = f"Copied {len(copied)} annotations to {target_drawing.Name or 'Unnamed'}."
+        if skipped:
+            message += f" Skipped {skipped} already in that drawing."
+        self.report({"INFO"}, message)
+
+
 class CreateDrawing(bpy.types.Operator):
     """Creates/refreshes a .svg drawing
 
@@ -698,6 +782,8 @@ class CreateDrawing(bpy.types.Operator):
                 layer_set = material
                 offset = 0
                 sense_factor = 1
+            else:
+                assert False, material
 
             camera_matrix_i = context.scene.camera.matrix_world.inverted()
 
@@ -722,7 +808,6 @@ class CreateDrawing(bpy.types.Operator):
             bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=0.000001)
             bmesh.ops.triangle_fill(bm, use_dissolve=True, edges=bm.edges)
 
-            prev_co = None
             if not usage:
                 sense_factor = 1  # Assume the extrusion vector points in the direction sense
                 no = tool.Drawing.get_extrusion_vector(element).normalized()
@@ -739,6 +824,8 @@ class CreateDrawing(bpy.types.Operator):
                 co = Vector((0.0, 0.0, offset))
                 no = tool.Drawing.get_extrusion_vector(element).normalized()
                 no = Vector([1.0, 0.0, 0.0])
+            else:
+                assert False, usage
             no *= sense_factor
             last_i = len(layer_set.MaterialLayers) - 1
             for i, layer in enumerate(layer_set.MaterialLayers):
@@ -906,6 +993,10 @@ class CreateDrawing(bpy.types.Operator):
         if os.path.isfile(svg_path) and self.props.should_use_linework_cache:
             return svg_path
 
+        ifc = tool.Ifc.get()
+        semantics = None
+        pairs = None
+
         # in case of printing multiple drawings we need to sync just once
         if self.sync and self.drawing_index == 0:
             with profile("sync"):
@@ -1309,6 +1400,18 @@ class CreateDrawing(bpy.types.Operator):
         self.svg_settings = ifcopenshell.geom.settings()
         self.svg_settings.set("dimensionality", ifcopenshell.ifcopenshell_wrapper.CURVES_SURFACES_AND_SOLIDS)
         self.svg_settings.set("iterator-output", ifcopenshell.ifcopenshell_wrapper.NATIVE)
+        # SVG edge classification (issue #3668). See edge-classification.md. Settings are
+        # per-drawing, stored in EPset_Drawing and read into self.cprops by import_camera_props.
+        try:
+            self.svg_settings.set("svg-use-edge-classification", self.cprops.use_edge_classification)
+            self.svg_settings.set("svg-render-crease-edges", self.cprops.render_creases)
+            self.svg_settings.set("svg-valley-angle-min-degrees", self.cprops.valley_angle_min_degrees)
+            self.svg_settings.set("svg-render-sharp-edges", self.cprops.render_sharp)
+            self.svg_settings.set("svg-ridge-angle-min-degrees", self.cprops.ridge_angle_min_degrees)
+            self.svg_settings.set("svg-emit-flush-edges", self.cprops.render_flush)
+        except Exception:
+            # Backwards compatibility with older ifcopenshell builds that don't expose these keys.
+            pass
         self.svg_buffer = ifcopenshell.geom.serializers.buffer()
         self.serialiser_settings = ifcopenshell.geom.serializer_settings()
         self.serialiser = ifcopenshell.geom.serializers.svg(
@@ -1452,6 +1555,15 @@ class CreateDrawing(bpy.types.Operator):
                 "Material.Name",
             ]
 
+        join_classes = ifcopenshell.util.element.get_pset(self.camera_element, "EPset_Drawing", "JoinClasses")
+        if join_classes:
+            join_classes = tuple(c.strip() for c in join_classes.split(",") if c.strip())
+        else:
+            # Architectural convention only merges these objects by default. E.g. pipe
+            # segments and fittings shouldn't merge. Users may override this per-drawing
+            # via the EPset_Drawing.JoinClasses property (e.g. to also join IfcCovering).
+            join_classes = ("IfcWall", "IfcSlab")
+
         group = root.find("{http://www.w3.org/2000/svg}g")
         joined_paths = {}
         self.is_manifold_cache = {}
@@ -1553,8 +1665,7 @@ class CreateDrawing(bpy.types.Operator):
                             )
                         path.attrib["d"] = d
 
-            # Architectural convention only merges these objects. E.g. pipe segments and fittings shouldn't merge.
-            if not element.is_a("IfcWall") and not element.is_a("IfcSlab"):
+            if not any(element.is_a(c) for c in join_classes):
                 continue
 
             keys = []
@@ -3586,7 +3697,7 @@ class EditSheet(bpy.types.Operator, tool.Ifc.Operator):
         if sheet.is_a("IfcDocumentInformation"):
             self.document_type = "SHEET"
             self.name = sheet.Name
-            self.identification = sheet.DocumentId if tool.Ifc.get_schema() == "IFC2X3" else sheet.Identification
+            self.identification = tool.Document.get_document_information_id(sheet)
         elif sheet.is_a("IfcDocumentReference") and tool.Drawing.get_reference_description(sheet) == "TITLEBLOCK":
             self.document_type = "TITLEBLOCK"
         else:

src/bonsai/bonsai/bim/module/drawing/prop.py

@@ -536,6 +536,50 @@ class BIMCameraProperties(PropertyGroup):
         default=True,
         update=get_update_layer_callback("has_annotation", "HasAnnotation"),
     )
+    use_edge_classification: BoolProperty(
+        name="Use Edge Classification",
+        description="Classify projection edges into boundary/outline/sharp/crease/flush "
+        "instead of drawing all linework identically. See edge-classification.md",
+        default=False,
+        update=get_update_layer_callback("use_edge_classification", "UseEdgeClassification"),
+    )
+    render_creases: BoolProperty(
+        name="Render Creases",
+        description="Render 'crease' (concave) projection edges",
+        default=True,
+        update=get_update_layer_callback("render_creases", "RenderCreases"),
+    )
+    valley_angle_min_degrees: FloatProperty(
+        name="Valley Angle Minimum",
+        description="Minimum concave dihedral deviation from flat, in degrees, for a projection "
+        "edge to be classified as 'crease' rather than 'flush'",
+        default=12.0,
+        min=0.0,
+        max=180.0,
+        update=get_update_layer_callback("valley_angle_min_degrees", "ValleyAngleMinDegrees"),
+    )
+    render_sharp: BoolProperty(
+        name="Render Sharp",
+        description="Render 'sharp' (convex) projection edges",
+        default=True,
+        update=get_update_layer_callback("render_sharp", "RenderSharp"),
+    )
+    ridge_angle_min_degrees: FloatProperty(
+        name="Ridge Angle Minimum",
+        description="Minimum convex dihedral deviation from flat, in degrees, for a projection "
+        "edge to be classified as 'sharp' rather than 'flush'",
+        default=45.0,
+        min=0.0,
+        max=180.0,
+        update=get_update_layer_callback("ridge_angle_min_degrees", "RidgeAngleMinDegrees"),
+    )
+    render_flush: BoolProperty(
+        name="Render Flush",
+        description="Render 'flush' projection edges (dihedral deviation below both ridge/valley "
+        "thresholds). Omitted by default",
+        default=False,
+        update=get_update_layer_callback("render_flush", "RenderFlush"),
+    )
     target_view: EnumProperty(
         name="Target View",
         default="PLAN_VIEW",

src/bonsai/bonsai/bim/module/drawing/scheduler.py

@@ -110,12 +110,14 @@ class Scheduler:
         y = self.margin
         rows = list(sheet.iter_rows())
         total_rows = len(rows)
+        x = None
         for i, row in enumerate(rows):
             # The last row may contain only null values
             if i == (total_rows - 1) and not [c for c in row if c.value is not None]:
                 continue
 
             x = self.margin
+            unmerged_height = None
             for cell in row:
                 if isinstance(cell, openpyxl.cell.cell.MergedCell):
                     column_letter = openpyxl.utils.get_column_letter(cell.column)
@@ -230,8 +232,11 @@ class Scheduler:
                 )
 
                 x += unmerged_width
+
+            assert unmerged_height is not None
             y += unmerged_height
 
+        assert x is not None
         total_width = x + self.margin
         total_height = y + self.margin
         self.svg["width"] = "{}mm".format(total_width)
@@ -375,6 +380,7 @@ class Scheduler:
         tri = 0
         stop_iterating_over_rows = False
         # TODO: row spans support?
+        x = None
         for tr in table.getElementsByType(TableRow):
             if stop_iterating_over_rows:
                 break
@@ -491,6 +497,7 @@ class Scheduler:
                 tri += 1
                 y += height
 
+        assert x is not None
         total_width = x + self.margin
         total_height = y + self.margin
         self.svg["width"] = "{}mm".format(total_width)

src/bonsai/bonsai/bim/module/drawing/shaders.py

@@ -102,16 +102,16 @@ void angle_circle_head(
     in vec4 circle_start, in float circle_angle,
     in bool counterclockwise,
     out vec4 head[CIRCLE_SEGS+1], out float angle_segs) {
-    
+
     // 1 added to CIRCLE_SEGS because we're number of vertices
     // for n segments is n+1
-    
+
     float angle_d;
     angle_d = PI * 2 / CIRCLE_SEGS; // 30d
     // need to bottom clamp it to 1, otherwise it causes Blender crash at extruding the curve
     angle_segs = max(1, ceil(circle_angle / angle_d));
     angle_d = circle_angle / angle_segs;
-    
+
     for(int i = 0; i < (angle_segs + 1); i++) {
         float angle = angle_d * i;
         if (counterclockwise) {
@@ -143,7 +143,7 @@ void cross_head(in vec4 dir, in float size, out vec4 head[3]) {
 #define do_vertex(pos, e) (do_vertex_util(pos, vec2(-(e).y, (e).x) / winsize.xy))
 #define do_vertex_win(pos, e) ( do_vertex( WIN2CLIP( pos ), e ) )
 
-// if vertex is shared by two segments of the line still need to emit it twice 
+// if vertex is shared by two segments of the line still need to emit it twice
 // to avoid smoothing artifacts
 // don't forget to initialize `vec2 EDGE_DIR` for macro to work
 // `pos0` / `pos1` - vertex position in clip space
@@ -197,10 +197,13 @@ void do_circle_head(vec4 pos_w, vec4 head[CIRCLE_SEGS]) {
 
 def add_verts_sequence(verts, start_i, output_verts, output_edges, closed=False):
     """Add sequence of verts to output lists, returns next vertex index"""
+    i = None
     for i, v in enumerate(verts[:-1], start_i):
         output_verts.append(v)
         output_edges.append((i, i + 1))
     output_verts.append(verts[-1])
+    assert i is not None
+
     if closed:
         output_edges.append((i + 1, start_i))
     return i + 2
@@ -273,7 +276,7 @@ class BaseShader:
     FRAG_GLSL = """
     uniform vec4 color;
     uniform float lineWidth;
-    
+
     in float smoothline;
     out vec4 fragColor;
     void main() {

src/bonsai/bonsai/bim/module/drawing/svgwriter.py

@@ -903,12 +903,8 @@ class SvgWriter:
                     continue
                 sheet = tool.Drawing.get_reference_document(sheet_reference)
                 if sheet:
-                    if tool.Ifc.get_schema() == "IFC2X3":
-                        reference_id = sheet_reference.ItemReference or "-"
-                        sheet_id = sheet.DocumentId or "-"
-                    else:
-                        reference_id = sheet_reference.Identification or "-"
-                        sheet_id = sheet.Identification or "-"
+                    reference_id = tool.Document.get_external_reference_id(sheet_reference) or "-"
+                    sheet_id = tool.Document.get_document_information_id(sheet) or "-"
                     return (reference_id, sheet_id)
                 break
         return ("-", "-")
@@ -1453,6 +1449,7 @@ class SvgWriter:
                     angle_tg = rise / run
                     angle = round(degrees(atan(angle_tg)))
                 else:
+                    angle_tg = None
                     angle = 90
 
                 # ues SLOPE_ANGLE as default
@@ -1466,6 +1463,7 @@ class SvgWriter:
                 elif object_type == "SLOPE_PERCENT":
                     if angle == 90:
                         return "-"
+                    assert angle_tg is not None
                     return f"{round(angle_tg * 100)} %"
 
             tag = element.Description or get_label_text()

src/bonsai/bonsai/bim/module/drawing/ui.py

@@ -113,6 +113,19 @@ class BIM_PT_camera(Panel):
             row.prop(props, "fill_mode")
             row = self.layout.row()
             row.prop(props, "cut_mode")
+
+        row = self.layout.row()
+        row.prop(props, "use_edge_classification")
+        if props.use_edge_classification:
+            row = self.layout.row()
+            row.prop(props, "render_creases")
+            row.prop(props, "valley_angle_min_degrees")
+            row = self.layout.row()
+            row.prop(props, "render_sharp")
+            row.prop(props, "ridge_angle_min_degrees")
+            row = self.layout.row()
+            row.prop(props, "render_flush")
+
         row = self.layout.row()
         row.prop(props, "width")
         row = self.layout.row()
@@ -319,6 +332,8 @@ class BIM_PT_drawings(Panel):
 
                 row3.separator(factor=0.5, type="SPACE")
 
+                row3.operator("bim.copy_annotation_to_drawing", icon="PASTEDOWN", text="")
+
                 row3.operator("bim.select_all_drawings", icon="CHECKBOX_HLT", text="")
                 row3.operator("bim.create_drawing", text="", icon="OUTPUT")
                 row3.operator("bim.convert_svg_to_dxf", text="", icon="SEQ_PREVIEW").view = active_drawing.name
@@ -964,14 +979,14 @@ class BIM_UL_sheets(bpy.types.UIList):
 
         if self.filter_name:
             filter_name = self.filter_name.lower()
-            active_sheet = None
+            active_sheet_index = None
             for sheet in data.sheets:
                 if sheet.is_sheet:
-                    active_sheet = sheet
                     active_sheet_index = len(flt_flags)
                 if filter_name in sheet.name.lower() or filter_name in sheet.identification.lower():
                     flt_flags.append(self.bitflag_filter_item)
                     if not sheet.is_sheet:
+                        assert active_sheet_index is not None
                         flt_flags[active_sheet_index] = self.bitflag_filter_item
                 else:
                     flt_flags.append(0)

src/bonsai/bonsai/bim/module/drawing/workspace.py

@@ -225,6 +225,9 @@ class AnnotationToolUI:
     def draw_edit_object_interface(cls, context):
         if DecoratorData.get_text_data(bpy.context.active_object):
             add_layout_hotkey_operator(cls.layout, "Edit Text", "S_E", "")
+        if bpy.ops.bim.copy_annotation_to_drawing.poll():
+            row = cls.layout.row(align=True)
+            row.operator("bim.copy_annotation_to_drawing", icon="PASTEDOWN", text="Copy To Drawing")
 
     @classmethod
     def draw_type_selection_interface(cls):

src/bonsai/bonsai/bim/module/geometry/helper.py

@@ -75,9 +75,13 @@ class Helper:
         for face in bm.faces:
             if len(face.verts) > 4:
                 potential_faces.append(face)
+
+        # TODO: replace with next(..., None)
+        face = None
         for face in potential_faces:
             if face.normal.z < -0.1:
                 break
+        assert face is not None
 
         profile = [l.vert.index for l in face.loops]
         extrusion = self.detect_extrusion_edge(bm, face)
@@ -108,10 +112,12 @@ class Helper:
         if not potential_faces:
             potential_faces = bm.faces
 
+        # TODO: replace with next(..., None)
+        face = None
         for face in potential_faces:
             if face.normal.z < -0.1:
                 break
-
+        assert face is not None
         profile = [l.vert.index for l in face.loops]
         extrusion = self.detect_extrusion_edge(bm, face)
 
@@ -145,9 +151,12 @@ class Helper:
             if total_verts > 4:
                 potential_faces.append(face)
 
+        # TODO: replace with next(..., None)
+        face = None
         for face in potential_faces:
             if face.normal.z < -0.1:
                 break
+        assert face is not None
 
         end_faces = []
         end_face_normal = face.normal

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -581,7 +581,11 @@ class UpdateRepresentation(bpy.types.Operator, tool.Ifc.Operator):
         if has_openings and not self.apply_openings:
             # Meshlike things with openings can only be updated without openings applied.
             if self.from_ui:
-                self.report({"ERROR"}, f"Object '{obj.name}' has openings - representation cannot be updated.")
+                self.report(
+                    {"ERROR"},
+                    f"Object '{obj.name}' has openings. "
+                    "ALT+click the button to bake the openings into the new representation.",
+                )
             return
 
         if not product.is_a("IfcGridAxis"):
@@ -3446,40 +3450,43 @@ class UnassignRepresentationItemStyle(bpy.types.Operator, tool.Ifc.Operator):
             self.report({"ERROR"}, "Couldn't find any styles associated with the active representation item.")
             return {"CANCELLED"}
 
-        # Resolve an object's active representation down to its base geometry items,
-        # unwrapping mapped items (Revit families) and boolean results (openings/cuts)
-        # so we reach the items that actually carry styles.
-        def get_base_representation_items(obj):
-            representation = tool.Geometry.get_active_representation(obj)
-            if not representation or not representation.is_a("IfcRepresentation"):
-                return
-            yield from ifcopenshell.util.representation.resolve_base_items(representation)
+        # Unassign matching styles from the active object itself
+        for style in active_styles:
+            tool.Style.assign_style_to_representation_item(active_representation_item, None)
+            tool.Geometry.reload_representation(active_obj)
+            break  # No need to check further if one matching style is found
 
-        # Unassign the style from the active representation item.
-        tool.Style.assign_style_to_representation_item(active_representation_item, None)
-        tool.Geometry.reload_representation(active_obj)
-
-        # Iterate over other selected objects and unassign matching styles.
+        # Iterate over selected objects and unassign matching styles
         for obj in context.selected_objects:
             if obj == active_obj:
-                continue
+                continue  # Skip the active object itself
 
-            for item in get_base_representation_items(obj):
-                item_styles = set()
-                if hasattr(item, "StyledByItem"):
-                    for styled_by_item in item.StyledByItem:
+            # Get the IFC entity directly from the object
+            element = tool.Ifc.get_entity(obj)
+            if not element:
+                continue  # Skip if no IFC entity is found
+
+            representation_item_id = element.Representation.Representations[0].Items[0].id()
+            representation_item = tool.Ifc.get_entity_by_id(representation_item_id)
+
+            if representation_item:
+                # Retrieve styles for the current representation item
+                styles = set()
+                if hasattr(representation_item, "StyledByItem"):
+                    for styled_by_item in representation_item.StyledByItem:
                         if hasattr(styled_by_item, "Styles"):
-                            item_styles.update(styled_by_item.Styles)
+                            styles.update(styled_by_item.Styles)
 
-                if item_styles & active_styles:
-                    tool.Style.assign_style_to_representation_item(item, None)
-                    tool.Geometry.reload_representation(obj)
-                    break  # Only remove one matching style per object
+                # Unassign matching styles
+                for style in styles:
+                    if style in active_styles:
+                        tool.Style.assign_style_to_representation_item(representation_item, None)
+                        tool.Geometry.reload_representation(obj)
+                        break  # No need to check further if one matching style is found
 
+        # Reload UI items
         bpy.ops.bim.disable_editing_representation_items()
         bpy.ops.bim.enable_editing_representation_items()
-        return {"FINISHED"}
-
 
 
 class EnableEditingRepresentationItemShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
@@ -3520,12 +3527,15 @@ class EditRepresentationItemShapeAspect(bpy.types.Operator, tool.Ifc.Operator):
         if props.representation_item_shape_aspect == "NEW":
             active_representation = tool.Geometry.get_active_representation(obj)
             # find IfcProductRepresentationSelect based on current representation
+            product_shape = None
             if hasattr(element, "Representation"):  # IfcProduct
                 product_shape = element.Representation
             else:  # IfcTypeProduct
                 for representation_map in element.RepresentationMaps:
                     if representation_map.MappedRepresentation == active_representation:
                         product_shape = representation_map
+            assert product_shape is not None
+
             previous_shape_aspect_id = props.active_item.shape_aspect_id
             # will be None if item didn't had a shape aspect
             previous_shape_aspect = tool.Ifc.get_entity_by_id(previous_shape_aspect_id)
@@ -3875,6 +3885,8 @@ class AddSweptAreaSolidItem(bpy.types.Operator, tool.Ifc.Operator):
             curve = builder.rectangle(size=Vector((0.5, 0.5)) / unit_scale)
         elif self.shape == "CYLINDER":
             curve = builder.circle(radius=0.25 / unit_scale)
+        else:
+            assert False, self.shape
         item = builder.extrude(
             curve,
             magnitude=0.5 / unit_scale,
@@ -4112,6 +4124,31 @@ class OverrideMoveSelect(bpy.types.Operator):
                 self.new_active_obj = obj
             return {"FINISHED"}
 
+        # Get arrays
+        ifc_file = tool.Ifc.get()
+        array_parents_to_move: list[bpy.types.Object] = []
+        for obj in list(context.selected_objects):
+            element = tool.Ifc.get_entity(obj)
+            if not element:
+                continue
+            pset = ifcopenshell.util.element.get_pset(element, "BBIM_Array")
+            if not pset:
+                continue
+            parent_element = ifc_file.by_guid(pset["Parent"])
+            parent_obj = tool.Ifc.get_object(parent_element)
+            if parent_obj not in array_parents_to_move:
+                array_parents_to_move.append(parent_obj)
+            if element.GlobalId != pset["Parent"]:
+                obj.select_set(False)
+
+        if array_parents_to_move:
+            for parent_obj in array_parents_to_move:
+                parent_element = tool.Ifc.get_entity(parent_obj)
+                for array_obj in tool.Array.get_all_objects(parent_element):
+                    array_obj.select_set(True)
+                self.new_active_obj = parent_obj
+            return {"FINISHED"}
+
         # Get nests
         props = tool.Nest.get_nest_props()
         not_editing_objs = [o.obj for o in props.not_editing_objects]

src/bonsai/bonsai/bim/module/group/operator.py

@@ -163,14 +163,52 @@ class AssignGroup(bpy.types.Operator, tool.Ifc.Operator):
     def _execute(self, context):
         if not self.is_assigning:
             return bpy.ops.bim.unassign_group(group=self.group)
+        ifc_file = tool.Ifc.get()
+        group = ifc_file.by_id(self.group)
         products = [
             element
             for o in tool.Blender.get_selected_objects(include_active=False)
             if (element := tool.Ifc.get_entity(o))
         ]
-        ifcopenshell.api.group.assign_group(tool.Ifc.get(), products=products, group=tool.Ifc.get().by_id(self.group))
+        relocated_annotations = self.unassign_from_previous_drawing(ifc_file, group, products)
+        ifcopenshell.api.group.assign_group(ifc_file, products=products, group=group)
+        self.relocate_annotations_to_drawing(relocated_annotations, group)
         self.report({"INFO"}, f"Assigned {len(products)} objects to group.")
 
+    def unassign_from_previous_drawing(self, ifc_file, group, products) -> list[ifcopenshell.entity_instance]:
+        """Assigning an annotation to a group that represents a drawing means the
+        annotation should belong to that drawing only, so it needs to leave
+        whichever drawing it was previously part of, instead of ending up
+        visible in both at once.
+        """
+        new_drawing = tool.Drawing.get_group_drawing(group)
+        if not new_drawing:
+            return []
+        relocated = []
+        for product in products:
+            if not product.is_a("IfcAnnotation") or product.ObjectType == "DRAWING":
+                continue
+            old_drawing = tool.Drawing.get_annotation_drawing(product)
+            if not old_drawing or old_drawing.id() == new_drawing.id():
+                continue
+            if old_group := tool.Drawing.get_drawing_group(old_drawing):
+                ifcopenshell.api.group.unassign_group(ifc_file, products=[product], group=old_group)
+            relocated.append(product)
+        return relocated
+
+    def relocate_annotations_to_drawing(self, products, group) -> None:
+        """Move the relocated annotations into the new drawing's collection and
+        depth, now that they have actually been assigned to its group.
+        """
+        if not products:
+            return
+        new_drawing = tool.Drawing.get_group_drawing(group)
+        new_camera = tool.Ifc.get_object(new_drawing) or tool.Drawing.import_drawing(new_drawing)
+        for product in products:
+            if obj := tool.Ifc.get_object(product):
+                tool.Drawing.ensure_annotation_in_drawing_plane(obj, camera=new_camera)
+                tool.Collector.assign(obj)
+
 
 class UnassignGroup(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.unassign_group"

src/bonsai/bonsai/bim/module/library/data.py

@@ -103,9 +103,7 @@ class LibraryReferencesData:
                 results.append(
                     {
                         "id": library.id(),
-                        "identification": (
-                            library.ItemReference if tool.Ifc.get_schema() == "IFC2X3" else library.Identification
-                        ),
+                        "identification": tool.Document.get_external_reference_id(library),
                         "name": library.Name or "Unnamed",
                     }
                 )

src/bonsai/bonsai/bim/module/light/operator.py

@@ -156,6 +156,7 @@ class RadianceRender(bpy.types.Operator):
         print(f"Quality: {quality}, Detail: {detail}, Variability: {variability}")
         print(f"Output directory: {output_dir}")
 
+        hdr_image_path, hdr_mask_path, sky_map_cal_path = None, None
         if use_hdr:
             hdr_image = "noon_grass_2k.hdr"
             hdr_mask = "noon_grass_2k_mask.hdr"
@@ -254,6 +255,9 @@ class RadianceRender(bpy.types.Operator):
         # 4 0 0 -1 180
 
         if use_hdr and choose_hdr_image == "Noon":
+            assert hdr_image_path is not None
+            assert hdr_mask_path is not None
+            assert sky_map_cal_path is not None
 
             with open(sky_file_path, "w") as f:
                 f.write(sky_description_str)

src/bonsai/bonsai/bim/module/misc/operator.py

@@ -418,6 +418,13 @@ class ImportQuickFavorites(bpy.types.Operator):
     bl_description = "Import operators from Blender's Quick Favorites menu, including their configured properties"
     bl_options = {"REGISTER", "UNDO"}
 
+    @classmethod
+    def poll(cls, context):
+        if bpy.app.version[:2] not in tool.Misc.QuickFavorites.OFFSET_USER_MENUS:
+            cls.poll_message_set(f"Blender version {bpy.app.version_string} is not supported.")
+            return False
+        return True
+
     def execute(self, context) -> set["rna_enums.OperatorReturnItems"]:
         props = tool.Misc.get_misc_props()
         props.quick_favorites.clear()

src/bonsai/bonsai/bim/module/model/array.py

@@ -564,6 +564,7 @@ class SelectAllArrayObjects(bpy.types.Operator):
                     except RuntimeError:
                         self.report({"ERROR"}, f"Objects that don't have an array parent, were deselected.")
                         object.select_set(False)
+                        continue
 
                     array_objects = tool.Array.get_all_objects(parent_element)
                     tool.Blender.set_objects_selection(

src/bonsai/bonsai/bim/module/model/decorator.py

@@ -93,6 +93,30 @@ def _stroke_lines_alpha(
     gpu.state.blend_set("NONE")
 
 
+def _connected_components(
+    vertex_groups: dict[int, list[bmesh.types.BMVert]],
+) -> list[list[bmesh.types.BMVert]]:
+    """Split each vertex group's members into their connected components,
+    since a duplicated arc/circle loop shares its source loop's group index."""
+    components = []
+    for verts in vertex_groups.values():
+        remaining = set(verts)
+        while remaining:
+            seed = remaining.pop()
+            stack = [seed]
+            component = [seed]
+            while stack:
+                v = stack.pop()
+                for edge in v.link_edges:
+                    other = edge.other_vert(v)
+                    if other in remaining:
+                        remaining.discard(other)
+                        stack.append(other)
+                        component.append(other)
+            components.append(component)
+    return components
+
+
 class ProfileDecorator:
     installed = None
 
@@ -265,7 +289,7 @@ class ProfileDecorator:
         # Draw arcs
         arc_centroids = []
         arc_segments = []
-        for arc in arcs.values():
+        for arc in _connected_components(arcs):
             if len(arc) != 3:
                 continue
             sorted_arc = [None, None, None]
@@ -292,7 +316,7 @@ class ProfileDecorator:
         # Draw circles
         circle_centroids = []
         circle_segments = []
-        for circle in circles.values():
+        for circle in _connected_components(circles):
             if len(circle) != 2:
                 continue
             p1 = obj.matrix_world @ circle[0].co

src/bonsai/bonsai/bim/module/model/mep.py

@@ -408,6 +408,8 @@ class MEPGenerator:
                     compare = tool.Cad.is_x(requested_value, fitting_value, compare_precision)
                 elif isinstance(fitting_value, list):
                     compare = tool.Cad.are_vectors_equal(requested_value, Vector(fitting_value), precision)
+                else:
+                    assert False, f"{key} {second_key}"
                 return compare
 
             ignore_keys = []
@@ -476,11 +478,13 @@ class MEPGenerator:
             if predefined_type == "OBSTRUCTION":
                 return packed_data
 
+            start_port = None
             for port in ports:
                 port_local_position = V(*port.ObjectPlacement.RelativePlacement.Location.Coordinates)
                 if tool.Cad.is_x(port_local_position.length, 0.0):
                     start_port = port
                     break
+            assert start_port is not None
 
             connected_port = tool.System.get_connected_port(start_port)
             connected_element = tool.System.get_port_relating_element(connected_port)

src/bonsai/bonsai/bim/module/model/product.py

@@ -325,7 +325,7 @@ class AddOccurrence(bpy.types.Operator, tool.Ifc.Operator):
         if self.from_invoke and str(self.relating_type_id) in AuthoringData.data["relating_type_id"]:
             props.relating_type_id = str(self.relating_type_id)
 
-        building_obj = None
+        building_obj, building_element = None, None
         if len(context.selected_objects) == 1 and context.active_object:
             building_obj = context.active_object
             building_element = tool.Ifc.get_entity(building_obj)

src/bonsai/bonsai/bim/module/model/profile.py

@@ -593,6 +593,8 @@ class DumbProfileJoiner:
             axisl = (profile2.matrix_world.inverted() @ axis1[1]) - (profile2.matrix_world.inverted() @ axis1[0])
         elif connection1 == "ATSTART":
             axisl = (profile2.matrix_world.inverted() @ axis1[0]) - (profile2.matrix_world.inverted() @ axis1[1])
+        else:
+            assert False, connection1
         xy_angle = degrees(Vector((1, 0)).angle_signed(axisl.normalized().to_2d()))
         if xy_angle >= -135 and xy_angle <= -45:
             closest_plane = "bottom"
@@ -617,6 +619,8 @@ class DumbProfileJoiner:
                 axisl = (profile1.matrix_world.inverted() @ axis2[1]) - (profile1.matrix_world.inverted() @ axis2[0])
             elif connection2 == "ATSTART":
                 axisl = (profile1.matrix_world.inverted() @ axis2[0]) - (profile1.matrix_world.inverted() @ axis2[1])
+            else:
+                assert False, connection2
             xy_angle2 = degrees(Vector((1, 0)).angle_signed(axisl.normalized().to_2d()))
             if xy_angle2 >= -135 and xy_angle2 <= -45:
                 closest_plane2 = "bottom"
@@ -844,6 +848,8 @@ class DumbProfileJoiner:
             else:
                 y_axis = obj.matrix_world.to_quaternion() @ Vector((0, 1, 0))
                 z_axis = obj.matrix_world.to_quaternion() @ Vector((-1, 0, 0))
+        else:
+            assert False, plane
         return self.create_matrix(p, x_axis, y_axis, z_axis)
 
     def create_matrix(self, p: Vector, x: Vector, y: Vector, z: Vector) -> Matrix:

src/bonsai/bonsai/bim/module/model/slab.py

@@ -508,6 +508,7 @@ class EditSketchExtrusionProfile(bpy.types.Operator, tool.Ifc.Operator):
         converter.run()
 
         profile = tool.Ifc.get().createIfcArbitraryClosedProfileDef("AREA")
+        curve = None
         for path in converter.paths:
             points = []
             lines = path[0]
@@ -517,6 +518,7 @@ class EditSketchExtrusionProfile(bpy.types.Operator, tool.Ifc.Operator):
                 points.append(tool.Ifc.get().createIfcCartesianPoint(local_point))
             points.append(points[0])
             curve = tool.Ifc.get().createIfcPolyline(points)
+        assert curve
         profile.OuterCurve = curve
 
         old_profile = extrusion.SweptArea

src/bonsai/bonsai/bim/module/model/wall.py

@@ -1577,6 +1577,7 @@ class DumbWallJoiner:
         # Get the ATEND connection from wall1 to use it in wall2
         relating_element = None
         connections = element1.ConnectedTo
+        relating_connection, description = ..., ...
         for conn in connections:
             if conn.is_a("IfcRelConnectsPathElements") and conn.RelatingConnectionType == "ATEND":
                 relating_element = conn.RelatedElement
@@ -1591,6 +1592,7 @@ class DumbWallJoiner:
                 description = conn.Description
                 bonsai.core.geometry.remove_connection(tool.Geometry, connection=conn)
         if relating_element:
+            assert relating_connection is not ... and description is not ...
             ifcopenshell.api.geometry.connect_path(
                 tool.Ifc.get(),
                 relating_element=relating_element,

src/bonsai/bonsai/bim/module/patch/operator.py

@@ -18,7 +18,7 @@
 
 import json
 from pathlib import Path
-from typing import TYPE_CHECKING, cast
+from typing import TYPE_CHECKING
 
 import bpy
 import ifcopenshell
@@ -122,8 +122,8 @@ class ExecuteIfcPatch(bpy.types.Operator):
         if props.should_load_from_memory and tool.Ifc.get():
             args["file"] = tool.Ifc.get()
         else:
-            args["input"] = cast(str, props.ifc_patch_input)
-            args["file"] = cast(ifcopenshell.file, ifcopenshell.open(props.ifc_patch_input))
+            args["input"] = props.ifc_patch_input
+            args["file"] = ifcopenshell.open(props.ifc_patch_input)
 
         # Store this in case the patch recipe resets the Blender session, such as by loading a new project.
         ifc_patch_output = props.ifc_patch_output or props.ifc_patch_input

src/bonsai/bonsai/bim/module/project/operator.py

@@ -714,6 +714,8 @@ class AppendLibraryElement(bpy.types.Operator, tool.Ifc.Operator):
             representations = element.RepresentationMaps or []
         elif element.is_a("IfcProduct"):
             representations = [element.Representation] if element.Representation else []
+        else:
+            assert False, element
         for representation in representations or []:
             for element in self.file.traverse(representation):
                 if not element.is_a("IfcRepresentationItem") or not element.StyledByItem:
@@ -2029,6 +2031,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
         project_props = tool.Project.get_project_props()
         prefs = tool.Blender.get_addon_preferences()
         project_props.use_relative_project_path = self.use_relative_path
+        old_history_size, old_undo_steps = None, None
         if prefs.should_disable_undo_on_save:
             old_history_size = tool.Ifc.get().history_size
             old_undo_steps = context.preferences.edit.undo_steps
@@ -2036,6 +2039,7 @@ class ExportIFC(bpy.types.Operator, ExportHelper):
             context.preferences.edit.undo_steps = 0
         IfcStore.execute_ifc_operator(self, context)
         if prefs.should_disable_undo_on_save:
+            assert old_history_size is not None and old_undo_steps is not None
             tool.Ifc.get().history_size = old_history_size
             context.preferences.edit.undo_steps = old_undo_steps
         return {"FINISHED"}

src/bonsai/bonsai/bim/module/pset/operator.py

@@ -113,6 +113,8 @@ class EditPset(bpy.types.Operator, tool.Ifc.Operator):
         elif props.active_pset_type == "QTO":
             pset = ifcopenshell.api.pset.add_qto(self.file, product=element, name=props.active_pset_name)
             props.active_pset_id = pset.id()
+        else:
+            assert False
 
         if self.properties:
             properties = json.loads(self.properties)

src/bonsai/bonsai/bim/module/pset/prop.py

@@ -228,6 +228,8 @@ def get_qto_name(self: "PsetProperties", context: bpy.types.Context) -> tool.Ble
     if "bpy.data.objects" in pset_type:
         if prop_type == "PsetProperties":
             results = get_object_qto_name(self, context)
+        else:
+            assert False
     elif prop_type == "TaskPsetProperties":
         results = get_task_qto_names(self, context)
     elif prop_type == "ResourcePsetProperties":

src/bonsai/bonsai/bim/module/pset/ui.py

@@ -480,6 +480,7 @@ class BIM_PT_material_psets(Panel):
     def draw(self, context):
         assert self.layout
         props = tool.Material.get_material_props()
+        ifc_definition_id = None
         if material := props.active_material:
             ifc_definition_id = material.ifc_definition_id
 

src/bonsai/bonsai/bim/module/root/operator.py

@@ -27,6 +27,7 @@ import ifcopenshell.api.material
 import ifcopenshell.api.pset
 import ifcopenshell.api.root
 import ifcopenshell.util.element
+import ifcopenshell.util.representation
 import ifcopenshell.util.schema
 import ifcopenshell.util.shape_builder
 import ifcopenshell.util.type
@@ -129,13 +130,25 @@ class ReassignClass(bpy.types.Operator, tool.Ifc.Operator):
             same_ifc_product = element.is_a(ifc_product)
 
             if not same_ifc_product:
-                if not (element.is_a("IfcElement") and ifc_product == "IfcElementType") and not (
-                    element.is_a("IfcElementType") and ifc_product == "IfcElement"
-                ):
-                    self.report(
-                        {"ERROR"}, f"Not supported class reassignment for object '{obj.name}' -> {ifc_product}."
+                # A spatial element (e.g. IfcSite) anchors the containment
+                # hierarchy, so only allow reassigning it to another family when
+                # it actually carries geometry - i.e. it's a real modelled thing
+                # (a bench dropped onto IfcSite -> IfcFurniture) rather than an
+                # empty spatial container we'd be turning into a loose element.
+                # IfcSpatialStructureElement covers IFC2X3, which has no
+                # IfcSpatialElement supertype.
+                is_spatial = element.is_a("IfcSpatialElement") or element.is_a("IfcSpatialStructureElement")
+                if is_spatial:
+                    has_geometry = (
+                        next(ifcopenshell.util.representation.get_representations_iter(element), None) is not None
                     )
-                    return {"CANCELLED"}
+                    if not has_geometry:
+                        self.report(
+                            {"ERROR"},
+                            f"Cannot reassign '{obj.name}' ({element.is_a()}) to {ifc_product}: "
+                            "a spatial element can only be reassigned to another class when it has geometry.",
+                        )
+                        return {"CANCELLED"}
 
             props = tool.Blender.get_object_bim_props(obj)
             props.is_reassigning_class = False
@@ -400,12 +413,13 @@ class UnlinkObject(bpy.types.Operator, tool.Ifc.Operator):
     skip_invoke: bpy.props.BoolProperty(default=False, options={"SKIP_SAVE"})
 
     def _execute(self, context):
+        objects: list[bpy.types.Object]
         if self.obj:
-            objects = [bpy.data.objects.get(self.obj)]
+            requested_obj = bpy.data.objects.get(self.obj)
+            objects = [requested_obj] if requested_obj is not None else []
         else:
             objects = context.selected_objects
 
-        objects: list[bpy.types.Object]
         for obj in objects:
             was_active_object = obj == context.active_object
 
@@ -617,10 +631,13 @@ class AddElement(bpy.types.Operator, tool.Ifc.Operator):
                     local_z = wall_matrix.to_3x3() @ Vector((0, 0, 1))
                     direction_sense = getattr(usage, "DirectionSense", "POSITIVE")
 
-                    if usage.LayerSetDirection == "AXIS2":
+                    layer_set_direction = usage.LayerSetDirection
+                    if layer_set_direction == "AXIS2":
                         z_axis = tuple(local_y) if direction_sense == "POSITIVE" else tuple(-local_y)
-                    elif usage.LayerSetDirection == "AXIS3":
+                    elif layer_set_direction == "AXIS3":
                         z_axis = tuple(local_z) if direction_sense == "POSITIVE" else tuple(-local_z)
+                    else:
+                        assert False, layer_set_direction
 
                     item = builder.extrude(
                         profile,
@@ -750,6 +767,8 @@ class AddElement(bpy.types.Operator, tool.Ifc.Operator):
                         WebThickness=default_web_thickness / unit_scale,
                         FlangeThickness=default_flange_thickness / unit_scale,
                     )
+                else:
+                    assert False, representation_template
 
             rel = ifcopenshell.api.material.assign_material(
                 tool.Ifc.get(), products=[element], type="IfcMaterialProfileSet"

src/bonsai/bonsai/bim/module/search/operator.py

@@ -1009,6 +1009,7 @@ class ColourByProperty(Operator):
         palette = props.palette
         is_qualitative = palette in ("tab10", "paired")
 
+        colours = None
         if is_qualitative:
             colours = tool.Search.get_qualitative_palette(palette)
 
@@ -1035,6 +1036,7 @@ class ColourByProperty(Operator):
                 if value in colourscheme:
                     colourscheme[value]["total"] += 1
                 else:
+                    assert colours is not None
                     colourscheme[value] = {"colour": next(colours)[0:3], "total": 1}
                 obj.color = (*colourscheme[value]["colour"], 1)
             else:
@@ -1139,6 +1141,7 @@ class SelectByProperty(Operator):
 
         is_qualitative = palette in ("tab10", "paired")
 
+        values = None
         if not is_qualitative:
             values = []
             for colour in props.colourscheme:

src/bonsai/bonsai/bim/module/sequence/gantt/index.js

@@ -12,7 +12,7 @@ function create_gantt_chart(json_data) {
         vShowTaskInfoLink: 1, // Show link in tool tip (0/1)
         vShowEndWeekDate: 0,  // Show/Hide the date for the last day of the week in header for daily
         vUseSingleCell: 10000, // Set the threshold cell per table row (Helps performance for large data.
-        vFormatArr: ['Day', 'Week', 'Month', 'Quarter'], // Even with setUseSingleCell using Hour format on such a large chart can cause issues in some browsers,
+        vFormatArr: ['Hour', 'Day', 'Week', 'Month', 'Quarter'], // vUseSingleCell keeps Hour usable on large charts.
         vShowRes: true, // Disable the resource column.
         vShowComp: false, // Disable the completion column.
         vShowDur: false, // Disable the duration column, because jsgantt doesn't calculate durations the way we want.

src/bonsai/bonsai/bim/module/sequence/ui.py

@@ -281,11 +281,11 @@ class BIM_PT_work_schedules(Panel):
     def draw_task_operators(self) -> None:
         row = self.layout.row(align=True)
         row.alignment = "RIGHT"
-        ifc_definition_id = None
+        task, ifc_definition_id = None, None
         if self.tprops.tasks and self.props.active_task_index < len(self.tprops.tasks):
             task = self.tprops.tasks[self.props.active_task_index]
             ifc_definition_id = task.ifc_definition_id
-        if ifc_definition_id:
+        if task and ifc_definition_id:
             if self.props.active_task_id:
                 if self.props.editing_task_type == "TASKTIME":
                     row.operator("bim.edit_task_time", text="", icon="CHECKMARK")
@@ -341,6 +341,8 @@ class BIM_PT_work_schedules(Panel):
             row.prop(self.props, "other_columns", text="")
             column_type, name = self.props.other_columns.split(".")
             data_type = "string"
+        else:
+            assert False, column_type
         row.operator("bim.set_task_sort_column", text="", icon="SORTALPHA").column = f"{column_type}.{name}"
         row.prop(
             self.props, "is_sort_reversed", text="", icon="SORT_DESC" if self.props.is_sort_reversed else "SORT_ASC"

src/bonsai/bonsai/bim/module/spatial/operator.py

@@ -516,7 +516,7 @@ class SetContainerVisibility(bpy.types.Operator):
         if self.mode == "ISOLATE":
             if tool.Ifc.get_schema() == "IFC2X3":
                 containers = tool.Ifc.get().by_type("IfcSpatialStructureElement")
-            elif tool.Ifc.get_schema() != "IFC2X3":
+            else:
                 containers = set(tool.Ifc.get().by_type("IfcSpatialElement"))
                 containers -= set(tool.Ifc.get().by_type("IfcSpatialZone"))
             for container in containers:

src/bonsai/bonsai/bim/module/spatial/ui.py

@@ -125,6 +125,7 @@ class BIM_PT_spatial_decomposition(Panel):
             row.label(text="Warning: No Default Container", icon="ERROR")
         row.operator("bim.import_spatial_decomposition", icon="FILE_REFRESH", text="")
 
+        ifc_definition_id = None
         if self.props.active_container:
             ifc_definition_id = self.props.active_container.ifc_definition_id
             row = self.layout.row(align=True)
@@ -170,6 +171,7 @@ class BIM_PT_spatial_decomposition(Panel):
 
         if not self.props.active_container:
             return
+        assert ifc_definition_id is not None
 
         container_has_elements = bool(self.props.total_elements)
         if container_has_elements:

src/bonsai/bonsai/bim/module/structural/load_decoration_data.py

@@ -71,7 +71,11 @@ class LoadByDirection(TypedDict):
 
 ProcessedLoad = TypedDict(
     "ProcessedLoad",
-    {"linear loads": LoadByDirection, "max linear load": float, "discrete loads": list[list[DiscreteConfigItem]]},
+    {
+        "linear loads": dict[str, LoadByDirection] | None,
+        "max linear load": float,
+        "discrete loads": list[list[DiscreteConfigItem]],
+    },
 )
 
 
@@ -845,13 +849,16 @@ class ShaderInfo:
         v = l1[1] + fac * (pos - l1[0])
         return v
 
-    def interpolate(self, pos: float, loadinfo: list[LoadConfigItem], start: int, end: int, key: str) -> np.ndarray:
+    def interpolate(self, pos: float, loadinfo: list[LoadConfigItem], start: int, end: int) -> np.ndarray:
         """interpolate the result vectors between load poits"""
         result = np.zeros(6)
         for i in range(6):
-            value1 = [loadinfo[start]["pos"], loadinfo[start][key][i]]  # [position, force_component]
-            value2 = [loadinfo[end]["pos"], loadinfo[end][key][i]]  #      [position, force_component]
-            result[i] = self.interp1d(value1, value2, pos)  #             interpolated [position, force_component]
+            # [position, force_component]
+            value1 = [loadinfo[start]["pos"], loadinfo[start]["load values"][i]]
+            # [position, force_component]
+            value2 = [loadinfo[end]["pos"], loadinfo[end]["load values"][i]]
+            # interpolated [position, force_component]
+            result[i] = self.interp1d(value1, value2, pos)
         return result
 
     def get_before_and_after(self, pos: float, load_config_list: list[list[LoadConfigItem]]) -> dict[str, list[float]]:
@@ -895,8 +902,8 @@ class ShaderInfo:
                         load_before += config[end]["load values"]
 
                 elif end - start == 1:
-                    load_before += self.interpolate(pos, config, start, end, "load values")
-                    load_after += self.interpolate(pos, config, start, end, "load values")
+                    load_before += self.interpolate(pos, config, start, end)
+                    load_after += self.interpolate(pos, config, start, end)
                 start += 1
                 end -= 1
         return_value = {"before": load_before.tolist(), "after": load_after.tolist()}

src/bonsai/bonsai/bim/module/style/ui.py

@@ -102,6 +102,7 @@ class BIM_PT_styles(Panel):
 
         # style ui tools
         if active_style:
+            style = active_style
             row = self.layout.row(align=True)
             if material := style.blender_material:
                 msprops = tool.Style.get_material_style_props(material)

src/bonsai/bonsai/bim/module/type/operator.py

@@ -20,6 +20,7 @@ from typing import TYPE_CHECKING
 
 import bpy
 import ifcopenshell.api.attribute
+import ifcopenshell.api.material
 import ifcopenshell.api.type
 import ifcopenshell.util.element
 import ifcopenshell.util.representation
@@ -115,51 +116,94 @@ class UnassignType(bpy.types.Operator, tool.Ifc.Operator):
     if TYPE_CHECKING:
         related_object: str
 
-    def _execute(self, context):
+    @staticmethod
+    def _reattach_styles(file: ifcopenshell.file, copied_entities: dict[int, ifcopenshell.entity_instance]) -> None:
+        """copy_deep only follows forward references, so IfcStyledItem (an inverse,
+        ``StyledByItem``) is not carried onto the copied geometry. Re-create a
+        styled item on each copy that points at the same presentation styles as
+        the original, so the unmapped occurrence keeps its appearance."""
+        for original_id, copied in copied_entities.items():
+            original = file.by_id(original_id)
+            for styled_item in getattr(original, "StyledByItem", None) or []:
+                file.create_entity(
+                    "IfcStyledItem",
+                    Item=copied,
+                    Styles=styled_item.Styles,
+                    Name=styled_item.Name,
+                )
+
+    @staticmethod
+    def unassign_and_unmap(obj: bpy.types.Object) -> None:
+        """Unassign the type from ``obj`` and bake a private copy of any mapped
+        representation onto it, so the occurrence keeps its geometry, styles, and
+        material once the type (the source of all three) is gone."""
+
         def exclude_callback(attribute):
             return attribute.is_a("IfcProfileDef") and attribute.ProfileName
 
-        self.file = tool.Ifc.get()
+        file = tool.Ifc.get()
+        element = tool.Ifc.get_entity(obj)
+        if not element or not element.is_a("IfcObject"):
+            return
+
+        # Capture the material inherited from the type before we sever the link,
+        # but only if the occurrence has no material of its own to override it.
+        own_material = ifcopenshell.util.element.get_material(element, should_inherit=False)
+        inherited_material = ifcopenshell.util.element.get_material(element, should_inherit=True)
+
+        ifcopenshell.api.type.unassign_type(file, related_objects=[element])
+
+        if element.Representation:
+            new_active_representation = None
+            active_representation = tool.Geometry.get_active_representation(obj)
+            active_context = active_representation.ContextOfItems
+            representations = []
+            for representation in element.Representation.Representations:
+                resolved_representation = ifcopenshell.util.representation.resolve_representation(representation)
+                if representation == resolved_representation:
+                    representations.append(representation)
+                else:
+                    # We must unmap representations, carrying over their styles.
+                    copied_entities: dict[int, ifcopenshell.entity_instance] = {}
+                    copied_representation = ifcopenshell.util.element.copy_deep(
+                        file,
+                        resolved_representation,
+                        exclude=["IfcGeometricRepresentationContext"],
+                        exclude_callback=exclude_callback,
+                        copied_entities=copied_entities,
+                    )
+                    UnassignType._reattach_styles(file, copied_entities)
+                    representations.append(copied_representation)
+                    if representation.ContextOfItems == active_context:
+                        new_active_representation = copied_representation
+            element.Representation.Representations = representations
+
+            if new_active_representation:
+                bonsai.core.geometry.switch_representation(
+                    tool.Ifc,
+                    tool.Geometry,
+                    obj=obj,
+                    representation=new_active_representation,
+                )
+
+        # Bake the inherited material down onto the occurrence now that its type
+        # link (and, in the delete-type case, the type itself) is gone. Usages are
+        # occurrence-specific and never inherited, so they need no handling here.
+        if inherited_material is not None and own_material is None:
+            material_type = inherited_material.is_a()
+            if material_type not in ("IfcMaterialLayerSetUsage", "IfcMaterialProfileSetUsage"):
+                ifcopenshell.api.material.assign_material(
+                    file, products=[element], type=material_type, material=inherited_material
+                )
+
+    def _execute(self, context):
         if self.related_object:
             related_objects = [bpy.data.objects[self.related_object]]
         else:
             related_objects = tool.Blender.get_selected_objects()
 
         for obj in related_objects:
-            element = tool.Ifc.get_entity(obj)
-            if not element or not element.is_a("IfcObject"):
-                continue
-            ifcopenshell.api.type.unassign_type(self.file, related_objects=[element])
-
-            if element.Representation:
-                new_active_representation = None
-                active_representation = tool.Geometry.get_active_representation(obj)
-                active_context = active_representation.ContextOfItems
-                representations = []
-                for representation in element.Representation.Representations:
-                    resolved_representation = ifcopenshell.util.representation.resolve_representation(representation)
-                    if representation == resolved_representation:
-                        representations.append(representation)
-                    else:
-                        # We must unmap representations.
-                        copied_representation = ifcopenshell.util.element.copy_deep(
-                            tool.Ifc.get(),
-                            resolved_representation,
-                            exclude=["IfcGeometricRepresentationContext"],
-                            exclude_callback=exclude_callback,
-                        )
-                        representations.append(copied_representation)
-                        if representation.ContextOfItems == active_context:
-                            new_active_representation = copied_representation
-                element.Representation.Representations = representations
-
-                if new_active_representation:
-                    bonsai.core.geometry.switch_representation(
-                        tool.Ifc,
-                        tool.Geometry,
-                        obj=obj,
-                        representation=new_active_representation,
-                    )
+            self.unassign_and_unmap(obj)
         return {"FINISHED"}
 
 
@@ -305,14 +349,82 @@ class SelectTypeObjects(bpy.types.Operator):
 
 class RemoveType(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.remove_type"
-    bl_label = "Remove Type"
+    bl_label = "Delete Type"
+    bl_description = (
+        "Delete this type. Its occurrences are kept but become untyped.\n\n"
+        "SHIFT+Click to also delete every occurrence of this type in the project"
+    )
     bl_options = {"REGISTER", "UNDO"}
     element: bpy.props.IntProperty()
+    also_delete_instances: bpy.props.BoolProperty(default=False, options={"SKIP_SAVE"})
+
+    if TYPE_CHECKING:
+        element: int
+        also_delete_instances: bool
+
+    @staticmethod
+    def _detach_type_material_set(element: ifcopenshell.entity_instance) -> None:
+        """Cascade-free removal of the type's IfcMaterialLayerSet / IfcMaterialProfileSet
+        association, called just before the type is deleted.
+
+        ``remove_product`` would otherwise route the type's material association
+        through ``unassign_material``, which deletes *every* usage of that set
+        across the model (documented behaviour, with an upstream TODO calling it
+        too aggressive) — stripping the material off the very occurrences we are
+        trying to keep. By unhooking the type<->set link by hand here, the type
+        has no material at delete time, so that cascade never fires and the set
+        plus the occurrences' usages survive intact."""
+        file = tool.Ifc.get()
+        material = ifcopenshell.util.element.get_material(element, should_inherit=False)
+        if not material or material.is_a() not in ("IfcMaterialLayerSet", "IfcMaterialProfileSet"):
+            return
+        for rel in list(getattr(element, "HasAssociations", None) or []):
+            if not (rel.is_a("IfcRelAssociatesMaterial") and rel.RelatingMaterial == material):
+                continue
+            remaining = [o for o in rel.RelatedObjects if o != element]
+            if remaining:
+                rel.RelatedObjects = remaining
+            else:
+                history = rel.OwnerHistory
+                file.remove(rel)
+                if history:
+                    ifcopenshell.util.element.remove_deep2(file, history)
+
+    def invoke(self, context, event):
+        self.also_delete_instances = event.shift
+        if self.also_delete_instances:
+            element = tool.Ifc.get().by_id(self.element)
+            count = len(ifcopenshell.util.element.get_types(element))
+            return context.window_manager.invoke_confirm(
+                self,
+                event,
+                title="Delete Type and Occurrences",
+                message=f"This will delete the type and all {count} of its occurrences.",
+                confirm_text="Delete",
+            )
+        return self.execute(context)
 
     def _execute(self, context):
         element = tool.Ifc.get().by_id(self.element)
+        occurrences = ifcopenshell.util.element.get_types(element)
+        if self.also_delete_instances:
+            for occurrence in occurrences:
+                occurrence_obj = tool.Ifc.get_object(occurrence)
+                if occurrence_obj:
+                    tool.Geometry.delete_ifc_object(occurrence_obj)
+        else:
+            # Keep the occurrences: bake their (previously type-mapped) geometry,
+            # styles, and inherited material onto each one so nothing is lost when
+            # the type is deleted...
+            for occurrence in occurrences:
+                occ_obj = tool.Ifc.get_object(occurrence)
+                if occ_obj:
+                    UnassignType.unassign_and_unmap(occ_obj)
+            # ...and keep any layer/profile-set material usages alive across the deletion.
+            self._detach_type_material_set(element)
         obj = tool.Ifc.get_object(element)
-        tool.Geometry.delete_ifc_object(obj)
+        if obj:
+            tool.Geometry.delete_ifc_object(obj)
 
 
 class RenameType(bpy.types.Operator, tool.Ifc.Operator):

src/bonsai/bonsai/bim/module/type/ui.py

@@ -144,8 +144,10 @@ class BIM_PT_type_attributes(Panel):
 
             bonsai.bim.helper.draw_attributes(props.type_attributes, layout)
         else:
-            row = layout.row()
+            row = layout.row(align=True)
             row.operator("bim.enable_editing_type_attributes", icon="GREASEPENCIL", text="Edit")
+            op = row.operator("bim.remove_type", icon="TRASH", text="")
+            op.element = TypeData.data["relating_type"]["id"]
 
             for attribute in TypeData.data["relating_type_attributes"]:
                 row = layout.row(align=True)

src/bonsai/bonsai/bim/module/void/operator.py

@@ -72,6 +72,7 @@ class AddOpening(bpy.types.Operator, tool.Ifc.Operator):
 
         opening_objects = [obj for obj in selected_objects if obj != target_object]
 
+        obj1 = ...
         for opening_obj in opening_objects:
             element1 = tool.Ifc.get_entity(target_object)
             obj1 = target_object
@@ -196,6 +197,7 @@ class AddOpening(bpy.types.Operator, tool.Ifc.Operator):
                 bpy.data.objects.remove(obj2)
 
         tool.Model.purge_scene_openings()
+        assert obj1 is not ...
         context.view_layer.objects.active = obj1
         return {"FINISHED"}
 

src/bonsai/bonsai/bim/ui.py

@@ -284,11 +284,13 @@ class GizmoPreferences(bpy.types.PropertyGroup):
         draw_gizmos_in_3d_viewport: bool
 
 
+_gizmo_pref_entry = None
 for _gizmo_pref_entry in tool.Parametric.EDIT_TYPES:
     GizmoPreferences.__annotations__[_gizmo_pref_entry.name] = BoolProperty(
         name=_gizmo_pref_entry.name.replace("_", " ").title(),
         default=True,
     )
+assert _gizmo_pref_entry is not None
 del _gizmo_pref_entry
 
 
@@ -394,12 +396,14 @@ class DefaultParameters(bpy.types.PropertyGroup):
     and gives the create operator a preset to copy from."""
 
 
+_default_params_entry = None
 for _default_params_entry in tool.Parametric.EDIT_TYPES:
     if not _default_params_entry.has_default_parameters:
         continue
     DefaultParameters.__annotations__[_default_params_entry.name] = bpy.props.PointerProperty(
         type=getattr(_model_prop, _default_params_entry.props_attr),
     )
+assert _default_params_entry is not None
 del _default_params_entry
 
 

src/bonsai/bonsai/core/covering.py

@@ -74,10 +74,11 @@ def add_instance_ceiling_covering_from_cursor(
         if not relating_type.is_a("IfcCoveringType"):
             relating_type = None
 
+    ceiling_height = None
     if selected_objects and active_obj:
-        x, y, z, h, mat = spatial.get_x_y_z_h_mat_from_obj(active_obj)
+        x, y, z, _, _ = spatial.get_x_y_z_h_mat_from_obj(active_obj)
     else:
-        x, y, z, h, mat = spatial.get_x_y_z_h_mat_from_cursor()
+        x, y, z, _, _ = spatial.get_x_y_z_h_mat_from_cursor()
         ceiling_height = covering.get_z_from_ceiling_height()
 
     space_polygon = spatial.get_space_polygon_from_context_visible_objects(x, y)
@@ -87,6 +88,7 @@ def add_instance_ceiling_covering_from_cursor(
 
     obj = spatial.create_object("Covering")
     spatial.set_obj_origin_to_cursor_position_and_zero_elevation(obj)
+    assert ceiling_height is not None
     spatial.translate_obj_to_z_location(obj, z + ceiling_height)
     spatial.assign_type_to_obj(obj)
     spatial.set_covering_representation_from_polygon(obj, space_polygon, polygon_is_si=True)
@@ -100,7 +102,9 @@ def regen_selected_covering_object(root: type[tool.Root], spatial: type[tool.Spa
     selected_objects = spatial.get_selected_objects()
 
     if selected_objects and active_obj:
-        x, y, z, h, mat = spatial.get_x_y_z_h_mat_from_obj(active_obj)
+        x, y, _, _, _ = spatial.get_x_y_z_h_mat_from_obj(active_obj)
+    else:
+        assert False, "Object has to be active and selected."
 
     space_polygon = spatial.get_space_polygon_from_context_visible_objects(x, y)
 

src/bonsai/bonsai/core/drawing.py

@@ -303,17 +303,7 @@ def add_drawing(
         ifc_representation_class=None,
     )
 
-    drawings_parent_group = None
-    for group in ifc.get().by_type("IfcGroup"):
-        if group.Name == "DRAWINGS" and group.ObjectType == "DRAWINGS":
-            drawings_parent_group = group
-            break
-
-    if not drawings_parent_group:
-        drawings_parent_group = ifc.run("group.add_group")
-        ifc.run(
-            "group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"}
-        )
+    drawings_parent_group = drawing.ensure_drawings_parent_group()
 
     group = ifc.run("group.add_group")
     ifc.run("group.edit_group", group=group, attributes={"Name": drawing_name, "ObjectType": "DRAWING"})
@@ -352,19 +342,7 @@ def add_drawing(
     )
     drawing.setup_shading_styles_path(shading_styles_path)
 
-    drawings_parent_document = None
-    for document in ifc.get().by_type("IfcDocumentInformation"):
-        if document.Name == "DRAWINGS" and document.Scope == "DRAWINGS":
-            drawings_parent_document = document
-            break
-
-    if not drawings_parent_document:
-        drawings_parent_document = ifc.run("document.add_information")
-        if ifc.get_schema() == "IFC2X3":
-            attributes = {"DocumentId": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
-        else:
-            attributes = {"Identification": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
-        ifc.run("document.edit_information", information=drawings_parent_document, attributes=attributes)
+    drawings_parent_document = drawing.ensure_drawings_parent_document()
 
     information = ifc.run("document.add_information", parent=drawings_parent_document)
     uri = drawing.get_default_drawing_path(drawing_name)
@@ -395,17 +373,7 @@ def duplicate_drawing(
     group = drawing_tool.get_drawing_group(new_drawing)
     ifc.run("group.unassign_group", group=group, products=[new_drawing])
 
-    drawings_parent_group = None
-    for parent_group in ifc.get().by_type("IfcGroup"):
-        if parent_group.Name == "DRAWINGS" and parent_group.ObjectType == "DRAWINGS":
-            drawings_parent_group = parent_group
-            break
-
-    if not drawings_parent_group:
-        drawings_parent_group = ifc.run("group.add_group")
-        ifc.run(
-            "group.edit_group", group=drawings_parent_group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"}
-        )
+    drawings_parent_group = drawing_tool.ensure_drawings_parent_group()
 
     new_group = ifc.run("group.add_group")
     ifc.run("group.edit_group", group=new_group, attributes={"Name": drawing_name, "ObjectType": "DRAWING"})
@@ -426,19 +394,7 @@ def duplicate_drawing(
     old_reference = drawing_tool.get_drawing_document(new_drawing)
     ifc.run("document.unassign_document", products=[new_drawing], document=old_reference)
 
-    drawings_parent_document = None
-    for document in ifc.get().by_type("IfcDocumentInformation"):
-        if document.Name == "DRAWINGS" and document.Scope == "DRAWINGS":
-            drawings_parent_document = document
-            break
-
-    if not drawings_parent_document:
-        drawings_parent_document = ifc.run("document.add_information")
-        if ifc.get_schema() == "IFC2X3":
-            attributes = {"DocumentId": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
-        else:
-            attributes = {"Identification": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
-        ifc.run("document.edit_information", information=drawings_parent_document, attributes=attributes)
+    drawings_parent_document = drawing_tool.ensure_drawings_parent_document()
 
     information = ifc.run("document.add_information", parent=drawings_parent_document)
     uri = drawing_tool.get_default_drawing_path(drawing_name)
@@ -455,6 +411,37 @@ def duplicate_drawing(
     return new_drawing
 
 
+def copy_annotations_to_drawing(
+    ifc: type[tool.Ifc],
+    collector: type[tool.Collector],
+    drawing_tool: type[tool.Drawing],
+    geometry: type[tool.Geometry],
+    annotations: list[ifcopenshell.entity_instance],
+    target_drawing: ifcopenshell.entity_instance,
+) -> list[ifcopenshell.entity_instance]:
+    """Duplicate annotations into another drawing, leaving the originals untouched."""
+    target_group = drawing_tool.get_drawing_group(target_drawing)
+    if not target_group:
+        return []
+    annotations = [a for a in annotations if drawing_tool.get_annotation_drawing(a) != target_drawing]
+    annotation_objs = [obj for a in annotations if (obj := ifc.get_object(a))]
+    if not annotation_objs:
+        return []
+    camera = ifc.get_object(target_drawing) or drawing_tool.import_drawing(target_drawing)
+    old_to_new, _ = geometry.duplicate_ifc_objects(annotation_objs)
+    copied: list[ifcopenshell.entity_instance] = []
+    for new_elements in old_to_new.values():
+        for new_element in new_elements:
+            if old_group := drawing_tool.get_drawing_group(new_element):
+                ifc.run("group.unassign_group", group=old_group, products=[new_element])
+            ifc.run("group.assign_group", group=target_group, products=[new_element])
+            new_obj = ifc.get_object(new_element)
+            drawing_tool.ensure_annotation_in_drawing_plane(new_obj, camera)
+            collector.assign(new_obj, should_clean_users_collection=True)
+            copied.append(new_element)
+    return copied
+
+
 def remove_drawing(
     ifc: type[tool.Ifc], drawing_tool: type[tool.Drawing], drawing: ifcopenshell.entity_instance
 ) -> None:
@@ -541,6 +528,7 @@ def add_annotation(
     drawing_tool.show_decorations()
     obj = drawing_tool.create_annotation_object(drawing, object_type)
     element = ifc.get_entity(obj)
+    relating_type_rep = None
     if not element:  # Brand new annotation
         relating_type_rep = drawing_tool.get_annotation_representation(relating_type) if relating_type else None
         element = drawing_tool.run_root_assign_class(

src/bonsai/bonsai/core/product.py

@@ -1,65 +0,0 @@
-# Bonsai - OpenBIM Blender Add-on
-# Copyright (C) 2026
-#
-# This file is part of Bonsai.
-#
-# Bonsai is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# Bonsai is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
-#
-# This file was generated with the assistance of an AI coding tool.
-
-from __future__ import annotations
-
-import math
-from collections.abc import Iterable
-from typing import TYPE_CHECKING
-
-import bonsai.core.geometry
-
-if TYPE_CHECKING:
-    import bpy
-
-    import bonsai.tool as tool
-
-
-Z_ROTATION_ALIGNMENT_TOLERANCE = 1e-9
-
-
-def _z_rotation_diff(target_z: float, source_z: float) -> float:
-    """Signed Z-Euler difference wrapped to [-π, π]."""
-    return (target_z - source_z + math.pi) % (2 * math.pi) - math.pi
-
-
-def copy_z_rotation_to_selected(
-    ifc: type[tool.Ifc],
-    geometry: type[tool.Geometry],
-    surveyor: type[tool.Surveyor],
-    *,
-    active: bpy.types.Object,
-    targets: Iterable[bpy.types.Object],
-    flip: bool = False,
-) -> int:
-    """Apply ``active``'s Z-Euler rotation to each target."""
-    source_z = surveyor.get_z_rotation(active)  # ty: ignore[missing-argument]
-    if flip:
-        source_z += math.pi
-    rotated = 0
-    for obj in targets:
-        target_z = surveyor.get_z_rotation(obj)  # ty: ignore[missing-argument]
-        if abs(_z_rotation_diff(target_z, source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
-            continue
-        surveyor.set_z_rotation(obj, source_z)  # ty: ignore[missing-argument]
-        rotated += 1
-        if ifc.get_entity(obj) is not None:
-            bonsai.core.geometry.edit_object_placement(ifc, geometry, surveyor, obj=obj)
-    return rotated

src/bonsai/bonsai/core/tool.py

@@ -354,6 +354,9 @@ class Drawing:
     def enable_editing_schedules(cls): pass
     def enable_editing_sheets(cls): pass
     def enable_editing_text(cls, obj): pass
+    def ensure_annotation_in_drawing_plane(cls, obj, camera=None): pass
+    def ensure_drawings_parent_document(cls): pass
+    def ensure_drawings_parent_group(cls): pass
     def ensure_unique_drawing_name(cls, name): pass
     def ensure_unique_identification(cls, identification): pass
     def export_font_size(cls, obj): pass
@@ -365,6 +368,7 @@ class Drawing:
     def generate_reference_attributes(cls, reference, **attributes): pass
     def generate_sheet_identification(cls): pass
     def get_annotation_context(cls, target_view, object_type=None): pass
+    def get_annotation_drawing(cls, element): pass
     def get_annotation_representation(cls, element_type): pass
     def get_assigned_product(cls, element): pass
     def get_assigned_product_workaround(cls, element): pass
@@ -382,6 +386,7 @@ class Drawing:
     def get_drawing_group(cls, drawing): pass
     def get_drawing_references(cls, drawing): pass
     def get_drawing_target_view(cls, drawing): pass
+    def get_group_drawing(cls, group): pass
     def get_group_elements(cls, group): pass
     def get_ifc_representation_class(cls, object_type): pass
     def get_name(cls, element): pass
@@ -395,6 +400,7 @@ class Drawing:
     def get_unit_system(cls): pass
     def import_assigned_product(cls, obj): pass
     def import_documents(cls, document_type): pass
+    def import_drawing(cls, drawing): pass
     def import_drawings(cls): pass
     def import_sheets(cls): pass
     def import_text_attributes(cls, obj): pass
@@ -1169,8 +1175,6 @@ class Style:
 @interface
 class Surveyor:
     def get_absolute_matrix(cls, obj): pass
-    def get_z_rotation(cls, obj): pass
-    def set_z_rotation(cls, obj, z): pass
 
 
 @interface

src/bonsai/bonsai/tool/brick.py

@@ -192,10 +192,9 @@ class Brick(bonsai.core.tool.Brick):
     def get_brick(cls, element: ifcopenshell.entity_instance) -> Union[str, None]:
         for rel in element.HasAssociations:
             if rel.is_a("IfcRelAssociatesLibrary"):
-                if tool.Ifc.get_schema() == "IFC2X3" and "#" in rel.RelatingLibrary.ItemReference:
-                    return rel.RelatingLibrary.ItemReference
-                if tool.Ifc.get_schema() != "IFC2X3" and "#" in rel.RelatingLibrary.Identification:
-                    return rel.RelatingLibrary.Identification
+                identification = tool.Document.get_external_reference_id(rel.RelatingLibrary)
+                if identification and "#" in identification:
+                    return identification
 
     @classmethod
     def get_brick_class(cls, element: ifcopenshell.entity_instance) -> Union[str, None]:

src/bonsai/bonsai/tool/cad.py

@@ -981,6 +981,7 @@ class Cad:
                         has_found_connected_edge = True
             loops.append(loop)
 
+        new_verts = None
         for loop in loops:
             all_verts = {v.index for e in loop for v in e.verts}
             possible_v1s = []
@@ -1084,6 +1085,7 @@ class Cad:
                     break
 
                 v1 = v2
+        assert new_verts is not None
 
         return new_verts
 

src/bonsai/bonsai/tool/cost.py

@@ -280,6 +280,8 @@ class Cost(bonsai.core.tool.Cost):
                     new = props.cost_item_processes.add()
                 elif related_object.is_a("IfcResource"):
                     new = props.cost_item_resources.add()
+                else:
+                    assert False, related_object
                 new.ifc_definition_id = related_object.id()
                 new.name = related_object.Name or "Unnamed"
 

src/bonsai/bonsai/tool/document.py

@@ -261,7 +261,8 @@ class Document(bonsai.core.tool.Document):
     def get_reference_document(cls, reference: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance | None:
         # TODO: migrate to util.document and replace all instances
         if reference.file.schema == "IFC2X3":
-            return (reference.ReferenceToDocument or (None))[0]
+            reference_to_document = reference.ReferenceToDocument
+            return reference_to_document[0] if reference_to_document else None
         return reference.ReferencedDocument
 
     @classmethod

src/bonsai/bonsai/tool/drawing.py

@@ -38,6 +38,7 @@ import ifcopenshell.api.context
 import ifcopenshell.api.document
 import ifcopenshell.api.drawing
 import ifcopenshell.api.geometry
+import ifcopenshell.api.group
 import ifcopenshell.api.pset
 import ifcopenshell.api.root
 import ifcopenshell.geom
@@ -755,6 +756,17 @@ class Drawing(bonsai.core.tool.Drawing):
             if rel.is_a("IfcRelAssignsToGroup") and rel.RelatingGroup.ObjectType == "DRAWING":
                 return rel.RelatingGroup
 
+    @classmethod
+    def get_group_drawing(cls, group: ifcopenshell.entity_instance) -> Union[ifcopenshell.entity_instance, None]:
+        """Get the drawing that owns this group, if the group represents a drawing."""
+        if group.ObjectType != "DRAWING":
+            return None
+        for rel in group.IsGroupedBy or []:
+            for related_object in rel.RelatedObjects:
+                if related_object.is_a("IfcAnnotation") and related_object.ObjectType == "DRAWING":
+                    return related_object
+        return None
+
     @classmethod
     def get_drawing_document(cls, drawing: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance:
         for rel in drawing.HasAssociations:
@@ -773,6 +785,32 @@ class Drawing(bonsai.core.tool.Drawing):
     def get_drawing_target_view(cls, drawing: ifcopenshell.entity_instance) -> str:
         return ifcopenshell.util.element.get_psets(drawing).get("EPset_Drawing", {}).get("TargetView", "MODEL_VIEW")
 
+    @classmethod
+    def ensure_drawings_parent_document(cls) -> ifcopenshell.entity_instance:
+        ifc_file = tool.Ifc.get()
+        for document in ifc_file.by_type("IfcDocumentInformation"):
+            if document.Name == "DRAWINGS" and document.Scope == "DRAWINGS":
+                return document
+        document = ifcopenshell.api.document.add_information(ifc_file)
+        if ifc_file.schema == "IFC2X3":
+            attributes = {"DocumentId": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
+        else:
+            attributes = {"Identification": "DRAWINGS", "Name": "DRAWINGS", "Scope": "DRAWINGS"}
+        ifcopenshell.api.document.edit_information(ifc_file, information=document, attributes=attributes)
+        return document
+
+    @classmethod
+    def ensure_drawings_parent_group(cls) -> ifcopenshell.entity_instance:
+        ifc_file = tool.Ifc.get()
+        for group in ifc_file.by_type("IfcGroup"):
+            if group.Name == "DRAWINGS" and group.ObjectType == "DRAWINGS":
+                return group
+        group = ifcopenshell.api.group.add_group(ifc_file)
+        ifcopenshell.api.group.edit_group(
+            ifc_file, group=group, attributes={"Name": "DRAWINGS", "ObjectType": "DRAWINGS"}
+        )
+        return group
+
     @classmethod
     def get_group_elements(cls, group: ifcopenshell.entity_instance) -> list[ifcopenshell.entity_instance]:
         for rel in group.IsGroupedBy or []:
@@ -1045,6 +1083,12 @@ class Drawing(bonsai.core.tool.Drawing):
         camera_props.has_annotation = True
         camera_props.target_view = "PLAN_VIEW"
         camera_props.is_nts = False
+        camera_props.use_edge_classification = False
+        camera_props.render_creases = True
+        camera_props.valley_angle_min_degrees = 12.0
+        camera_props.render_sharp = True
+        camera_props.ridge_angle_min_degrees = 45.0
+        camera_props.render_flush = False
         camera.shift_x = 0.0
         camera.shift_y = 0.0
 
@@ -1074,6 +1118,18 @@ class Drawing(bonsai.core.tool.Drawing):
                 camera_props.has_annotation = bool(pset["HasAnnotation"])
             if "IsNTS" in pset:
                 camera_props.is_nts = bool(pset["IsNTS"])
+            if "UseEdgeClassification" in pset:
+                camera_props.use_edge_classification = bool(pset["UseEdgeClassification"])
+            if "RenderCreases" in pset:
+                camera_props.render_creases = bool(pset["RenderCreases"])
+            if "ValleyAngleMinDegrees" in pset:
+                camera_props.valley_angle_min_degrees = float(pset["ValleyAngleMinDegrees"])
+            if "RenderSharp" in pset:
+                camera_props.render_sharp = bool(pset["RenderSharp"])
+            if "RidgeAngleMinDegrees" in pset:
+                camera_props.ridge_angle_min_degrees = float(pset["RidgeAngleMinDegrees"])
+            if "RenderFlush" in pset:
+                camera_props.render_flush = bool(pset["RenderFlush"])
             if "DPI" in pset:
                 camera_props.dpi = int(pset["DPI"])
             if "LineworkMode" in pset:
@@ -1140,10 +1196,7 @@ class Drawing(bonsai.core.tool.Drawing):
             new = documents_collection.add()
             new.ifc_definition_id = schedule.id()
             new.name = schedule.Name or "Unnamed"
-            if tool.Ifc.get_schema() == "IFC2X3":
-                new.identification = schedule.DocumentId
-            else:
-                new.identification = schedule.Identification
+            new.identification = tool.Document.get_document_information_id(schedule) or ""
 
     @classmethod
     def get_sheet_identification(cls, sheet: ifcopenshell.entity_instance) -> str:
@@ -1184,10 +1237,7 @@ class Drawing(bonsai.core.tool.Drawing):
                 new.ifc_definition_id = reference.id()
                 new.is_sheet = False
 
-                if tool.Ifc.get_schema() == "IFC2X3":
-                    new.identification = reference.ItemReference or ""
-                else:
-                    new.identification = reference.Identification or ""
+                new.identification = tool.Document.get_external_reference_id(reference) or ""
 
                 new.name = os.path.basename(reference.Location)
                 new.reference_type = reference_description
@@ -2423,9 +2473,8 @@ class Drawing(bonsai.core.tool.Drawing):
     def get_reference_document(
         cls, reference: ifcopenshell.entity_instance
     ) -> Union[ifcopenshell.entity_instance, None]:
-        if tool.Ifc.get_schema() == "IFC2X3":
-            return reference.ReferenceToDocument[0]
-        return reference.ReferencedDocument
+        # TODO: migrate to document.get_reference_document.
+        return tool.Document.get_reference_document(reference)
 
     @classmethod
     def select_assigned_product(cls, context: bpy.types.Context) -> None:
@@ -2555,16 +2604,15 @@ class Drawing(bonsai.core.tool.Drawing):
             if not obj:
                 continue
             current_representation = tool.Geometry.get_active_representation(obj)
+            current_representation_subcontext = None
             if current_representation:
                 subcontext = current_representation.ContextOfItems
                 current_representation_subcontext = tool.Geometry.get_subcontext_parameters(subcontext)
 
-            has_context = False
             for subcontext in subcontexts:
                 # prioritize already active representation if it matches the subcontext
                 # (element could have multiple representations in the same subcontext)
-                if current_representation and subcontext == current_representation_subcontext:
-                    has_context = True
+                if current_representation_subcontext and subcontext == current_representation_subcontext:
                     break
                 priority_representation = ifcopenshell.util.representation.get_representation(element, *subcontext)
                 if priority_representation:
@@ -2574,7 +2622,6 @@ class Drawing(bonsai.core.tool.Drawing):
                         obj=obj,
                         representation=priority_representation,
                     )
-                    has_context = True
                     break
 
         linked_handles: set[bpy.types.Object] = set()

src/bonsai/bonsai/tool/feature.py

@@ -23,7 +23,6 @@ from typing import TYPE_CHECKING
 
 import bpy
 import ifcopenshell.api.feature
-import ifcopenshell.util.representation
 
 import bonsai.core.geometry
 import bonsai.core.tool
@@ -50,6 +49,7 @@ class Feature(bonsai.core.tool.Feature):
                 has_visible_openings = True
                 break
 
+        element_had_openings = None
         for feature_obj in feature_objs:
             feature_element = tool.Ifc.get_entity(feature_obj)
 
@@ -58,7 +58,6 @@ class Feature(bonsai.core.tool.Feature):
                 bonsai.core.geometry.edit_object_placement(tool.Ifc, tool.Geometry, tool.Surveyor, obj=featured_obj)
 
             element_had_openings = tool.Geometry.has_openings(featured_element)
-            body_context = ifcopenshell.util.representation.get_context(tool.Ifc.get(), "Model", "Body")
             ifcopenshell.api.feature.add_feature(tool.Ifc.get(), feature=feature_element, element=featured_element)
 
             if tool.Ifc.is_moved(feature_obj):
@@ -73,6 +72,7 @@ class Feature(bonsai.core.tool.Feature):
             if voided_obj.data:
                 if tool.Ifc.is_edited(voided_obj):
                     voided_element_ = tool.Ifc.get_entity(voided_obj)
+                    assert element_had_openings is not None
                     if element_had_openings or (voided_element_ != featured_element and voided_element_.HasOpenings):
                         voided_obj.scale = (1.0, 1.0, 1.0)
                         tool.Ifc.finish_edit(voided_obj)

src/bonsai/bonsai/tool/geometry.py

@@ -33,7 +33,6 @@ from typing import (
     Optional,
     TypeGuard,
     Union,
-    cast,
     get_args,
 )
 
@@ -758,6 +757,7 @@ class Geometry(bonsai.core.tool.Geometry):
             # its centroid not obscured (tested via raycasting) by any other
             # face.
             distance = max(obj.dimensions.xyz)
+            min_y, max_z = None, None
             if axis == "+Z":
                 max_z = max([co[2] for co in obj.bound_box]) + 0.002
                 direction = Vector((0, 0, -1))
@@ -772,8 +772,10 @@ class Geometry(bonsai.core.tool.Geometry):
                 if direction.dot(face.normal) > 0:
                     continue
                 if axis == "+Z":
+                    assert max_z is not None
                     face_centroid_at_max = Vector((*face.calc_center_median().xy, max_z))
                 elif axis == "-Y":
+                    assert min_y is not None
                     centroid = face.calc_center_median()
                     face_centroid_at_max = Vector((centroid.x, min_y, centroid.z))
                 face_centroid_at_max = obj.matrix_world @ face_centroid_at_max
@@ -1149,6 +1151,9 @@ class Geometry(bonsai.core.tool.Geometry):
         settings.set("layerset-first", True)
         settings.set("keep-bounding-boxes", True)
         settings.set("dimensionality", ifcopenshell.ifcopenshell_wrapper.CURVES_SURFACES_AND_SOLIDS)
+        settings.set("mesher-linear-deflection", ifc_import_settings.deflection_tolerance)
+        settings.set("mesher-angular-deflection", ifc_import_settings.angular_tolerance)
+        geometry_library = ifc_import_settings.geometry_library
 
         ifc_importer = bonsai.bim.import_ifc.IfcImporter(ifc_import_settings)
         ifc_importer.file = tool.Ifc.get()
@@ -1160,7 +1165,11 @@ class Geometry(bonsai.core.tool.Geometry):
         shape = None
         if elements:
             iterator = ifcopenshell.geom.iterator(
-                settings, tool.Ifc.get(), multiprocessing.cpu_count(), include=elements
+                settings,
+                tool.Ifc.get(),
+                multiprocessing.cpu_count(),
+                include=elements,
+                geometry_library=geometry_library,
             )
         else:
             iterator = None  # For example, when switching representation of a type with no occurrences
@@ -1215,7 +1224,9 @@ class Geometry(bonsai.core.tool.Geometry):
         for element in element_types:
             if obj := tool.Ifc.get_object(element):
                 if representation := ifcopenshell.util.representation.get_representation(element, context):
-                    geometry = ifcopenshell.geom.create_shape(settings, representation)
+                    geometry = ifcopenshell.geom.create_shape(
+                        settings, representation, geometry_library=geometry_library
+                    )
                     mesh_name = tool.Loader.get_mesh_name_from_shape(geometry)
                     mesh = meshes.get(mesh_name)
                     if mesh is None:
@@ -1886,6 +1897,7 @@ class Geometry(bonsai.core.tool.Geometry):
         """NOTE: we assume that all items belonged to the same representation and to the same shape aspect"""
         ifc_file = tool.Ifc.get()
         previous_shape_aspect = None
+        base_representation = None
         for inverse in ifc_file.get_inverse(representation_items[0]):
             if inverse.is_a("IfcShapeRepresentation"):
                 if inverse.OfShapeAspect:
@@ -1895,6 +1907,7 @@ class Geometry(bonsai.core.tool.Geometry):
                     previous_shape_aspect = inverse.OfShapeAspect[0]
                 else:
                     base_representation = inverse
+        assert base_representation
 
         # remove item from previous shape aspect
         if previous_shape_aspect:
@@ -2187,7 +2200,7 @@ class Geometry(bonsai.core.tool.Geometry):
             setattr(item, attribute.name, attribute.get_value())
 
         if item.is_a("IfcSweptAreaSolid"):
-            item_profile = cast(str, props.item_profile)
+            item_profile = props.item_profile
             profile = item.SweptArea
             profile_name: Union[str, None] = profile.ProfileName
             if item_profile == "-":
@@ -2212,6 +2225,7 @@ class Geometry(bonsai.core.tool.Geometry):
         assert item
         obj.data.clear_geometry()
 
+        cartesian_point_offset = None
         if item.is_a("IfcHalfSpaceSolid"):
             bm = bmesh.new()
             bmesh.ops.create_grid(bm, size=0.5)

src/bonsai/bonsai/tool/loader.py

@@ -197,7 +197,6 @@ class Loader(bonsai.core.tool.Loader):
         cls, blender_material: bpy.types.Material, surface_style: ifcopenshell.entity_instance
     ) -> None:
         surface_style = cls.surface_style_to_dict(surface_style)
-        surface_style: dict[str, Any]
 
         cls.create_surface_style_shading(blender_material, surface_style)
 
@@ -1088,18 +1087,21 @@ class Loader(bonsai.core.tool.Loader):
         bm = bmesh.new()
         bm.from_mesh(mesh)
         prev_co = None
-        if usage.LayerSetDirection == "AXIS2":
+        layer_set_direction = usage.LayerSetDirection
+        if layer_set_direction == "AXIS2":
             co = Vector((0.0, offset, 0.0))
             no = cls.get_extrusion_vector(element).normalized()
             no = no.cross(Vector([1.0, 0.0, 0.0]))
-        elif usage.LayerSetDirection == "AXIS3":
+        elif layer_set_direction == "AXIS3":
             co = Vector((0.0, 0.0, offset))
             no = cls.get_extrusion_vector(element).normalized()
             no = Vector([0.0, 0.0, 1.0])
-        elif usage.LayerSetDirection == "AXIS1":
+        elif layer_set_direction == "AXIS1":
             co = Vector((0.0, 0.0, offset))
             no = cls.get_extrusion_vector(element).normalized()
             no = Vector([1.0, 0.0, 0.0])
+        else:
+            assert False, layer_set_direction
         no *= sense_factor
         # Cache this
         body = ifcopenshell.util.representation.get_context(tool.Ifc.get(), "Model", "Body", "MODEL_VIEW")
@@ -1109,6 +1111,7 @@ class Loader(bonsai.core.tool.Loader):
             if style := tool.Ifc.get_entity(material):
                 styles[style] = i
         last_i = len(layer_set.MaterialLayers) - 1
+        bisect_geom = None
         for i, layer in enumerate(layer_set.MaterialLayers):
             if i != last_i:
                 prev_co = co.copy()
@@ -1122,6 +1125,7 @@ class Loader(bonsai.core.tool.Loader):
             if (material_index := styles.get(style, None)) is None:
                 material_index = len(mesh.materials)
                 mesh.materials.append(tool.Ifc.get_object(style))
+            assert bisect_geom is not None
             if i == last_i:
                 for face in bisect_geom["geom"]:
                     if isinstance(face, bmesh.types.BMFace):
@@ -1287,6 +1291,7 @@ class Loader(bonsai.core.tool.Loader):
             polyline.material_index = material_index
             return polyline
 
+        item = None
         for item_data, item_style in zip(rep_items, item_styles):
             item = item_data["item"]
 
@@ -1314,6 +1319,7 @@ class Loader(bonsai.core.tool.Loader):
                 polyline.points.add(1)
                 polyline.points[-1].co = native_data["matrix"] @ Vector(v2)
 
+        assert item is not None
         curve.bevel_depth = unit_scale * item.Radius
         thickness = None
         if (inner_radius := item.InnerRadius) and (thickness := max(item.Radius - inner_radius, 0)):

src/bonsai/bonsai/tool/misc.py

@@ -112,10 +112,14 @@ class Misc(bonsai.core.tool.Misc):
         reading data and never writing, to avoid the possibility of corrupting user preferences.
         """
 
+        # Byte offset of UserDef.user_menus within the UserDef C struct, per (major, minor)
+        # Blender version. Shifts whenever UserDef's fields change, so must be re-derived
+        # per version (e.g. from that Blender build's SDNA).
         OFFSET_USER_MENUS: dict[tuple[int, int], int] = {
             (4, 5): 10032,
             (5, 0): 10032,
             (5, 1): 10032,
+            (5, 2): 10800,
         }
 
         @classmethod
@@ -216,10 +220,12 @@ class Misc(bonsai.core.tool.Misc):
                         related_objects.append((element, ifcopenshell.util.placement.get_storey_elevation(element)))
         related_objects = sorted(related_objects, key=lambda e: e[1])
         storey_elevation = None
+        i = None
         for i, related_object in enumerate(related_objects):
             if related_object[0] == storey:
                 storey_elevation = related_object[1]
                 break
+        assert i is not None
         if i + total_storeys < len(related_objects):
             next_storey_elevation = related_objects[i + total_storeys][1]
             unit_scale = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())

src/bonsai/bonsai/tool/model.py

@@ -2292,32 +2292,18 @@ class Model(bonsai.core.tool.Model):
         deform_layer = bm.verts.layers.deform.active
 
         # Sanity check
-        group_verts = {"IFCARCINDEX": {}, "IFCCIRCLE": {}}
         if deform_layer:
             for vert in bm.verts:
                 vert_group_indices = tool.Blender.bmesh_get_vertex_groups(vert, deform_layer)
-                is_circle = False
-                for group_index in vert_group_indices:
-                    group_type = "IFCARCINDEX" if group_index in groups["IFCARCINDEX"] else "IFCCIRCLE"
-                    group_verts[group_type].setdefault(group_index, 0)
-                    group_verts[group_type][group_index] += 1
-                    if group_type == "IFCCIRCLE":
-                        is_circle = True
+                is_circle = any(gi in groups["IFCCIRCLE"] for gi in vert_group_indices)
+                is_arc = any(gi in groups["IFCARCINDEX"] for gi in vert_group_indices)
+                if (is_circle or is_arc) and not vert.link_edges:
+                    return (False, "CIRCLE" if is_circle else "3POINT_ARC")
                 if is_circle:
                     pass  # Circles are allowed to be unclosed
                 elif len(vert.link_edges) != 2:  # Unclosed loop or forked loop
                     return (False, "UNCLOSED_LOOP")
 
-        for group_type, group_counts in group_verts.items():
-            if group_type == "IFCARCINDEX":
-                for group_count in group_counts.values():
-                    if group_count != 3:  # Each arc needs 3 verts
-                        return (False, "3POINT_ARC")
-            elif group_type == "IFCCIRCLE":
-                for group_count in group_counts.values():
-                    if group_count != 2:  # Each circle needs 2 verts
-                        return (False, "CIRCLE")
-
         loop_edges = list(bm.edges)
 
         # Create loops from edges
@@ -2340,6 +2326,28 @@ class Model(bonsai.core.tool.Model):
                         has_found_connected_edge = True
             loops.append(loop)
 
+        # Sanity check, per loop rather than across the whole mesh
+        if deform_layer:
+            for loop in loops:
+                loop_group_counts = {"IFCARCINDEX": {}, "IFCCIRCLE": {}}
+                loop_verts = {v for edge in loop for v in edge.verts}
+                for vert in loop_verts:
+                    for group_index in tool.Blender.bmesh_get_vertex_groups(vert, deform_layer):
+                        if group_index in groups["IFCARCINDEX"]:
+                            group_type = "IFCARCINDEX"
+                        elif group_index in groups["IFCCIRCLE"]:
+                            group_type = "IFCCIRCLE"
+                        else:
+                            continue
+                        loop_group_counts[group_type].setdefault(group_index, 0)
+                        loop_group_counts[group_type][group_index] += 1
+                for group_count in loop_group_counts["IFCARCINDEX"].values():
+                    if group_count != 3:  # Each arc needs 3 verts
+                        return (False, "3POINT_ARC")
+                for group_count in loop_group_counts["IFCCIRCLE"].values():
+                    if group_count != 2:  # Each circle needs 2 verts
+                        return (False, "CIRCLE")
+
         tmp = ifcopenshell.file(schema=tool.Ifc.get().schema)
 
         def is_in_group(v: bmesh.types.BMVert, group_name: str) -> bool:
@@ -2520,27 +2528,11 @@ class Model(bonsai.core.tool.Model):
         deform_layer = bm.verts.layers.deform.active
 
         # Sanity check
-        group_verts = {"IFCARCINDEX": {}, "IFCCIRCLE": {}}
         if deform_layer:
             for vert in bm.verts:
-                vert_group_indices = tool.Blender.bmesh_get_vertex_groups(vert, deform_layer)
-                for group_index in vert_group_indices:
-                    group_type = "IFCARCINDEX" if group_index in groups["IFCARCINDEX"] else "IFCCIRCLE"
-                    group_verts[group_type].setdefault(group_index, 0)
-                    group_verts[group_type][group_index] += 1
                 if len(vert.link_edges) > 2:  # Forked loop
                     return (False, "FORKED_LOOP")
 
-        for group_type, group_counts in group_verts.items():
-            if group_type == "IFCARCINDEX":
-                for group_count in group_counts.values():
-                    if group_count != 3:  # Each arc needs 3 verts
-                        return (False, "3POINT_ARC")
-            elif group_type == "IFCCIRCLE":
-                for group_count in group_counts.values():
-                    if group_count != 2:  # Each circle needs 2 verts
-                        return (False, "CIRCLE")
-
         loop_edges = list(bm.edges)
 
         # Create loops from edges
@@ -2563,6 +2555,28 @@ class Model(bonsai.core.tool.Model):
                         has_found_connected_edge = True
             loops.append(loop)
 
+        # Sanity check, per loop rather than across the whole mesh
+        if deform_layer:
+            for loop in loops:
+                loop_group_counts = {"IFCARCINDEX": {}, "IFCCIRCLE": {}}
+                loop_verts = {v for edge in loop for v in edge.verts}
+                for vert in loop_verts:
+                    for group_index in tool.Blender.bmesh_get_vertex_groups(vert, deform_layer):
+                        if group_index in groups["IFCARCINDEX"]:
+                            group_type = "IFCARCINDEX"
+                        elif group_index in groups["IFCCIRCLE"]:
+                            group_type = "IFCCIRCLE"
+                        else:
+                            continue
+                        loop_group_counts[group_type].setdefault(group_index, 0)
+                        loop_group_counts[group_type][group_index] += 1
+                for group_count in loop_group_counts["IFCARCINDEX"].values():
+                    if group_count != 3:  # Each arc needs 3 verts
+                        return (False, "3POINT_ARC")
+                for group_count in loop_group_counts["IFCCIRCLE"].values():
+                    if group_count != 2:  # Each circle needs 2 verts
+                        return (False, "CIRCLE")
+
         tmp = ifcopenshell.file(schema=tool.Ifc.get().schema)
 
         def is_in_group(v: bmesh.types.BMVert, group_name: str) -> bool:

src/bonsai/bonsai/tool/parametric.py

@@ -641,6 +641,8 @@ del _edit_type_names
 # call sites can reference ``tool.Parametric.ROOF`` directly. Renaming a
 # registry entry renames the constant; a typo at the call site surfaces as
 # AttributeError at module load.
+_entry = None
 for _entry in Parametric.EDIT_TYPES:
     setattr(Parametric, _entry.name.upper(), _entry)
+assert _entry is not None
 del _entry

src/bonsai/bonsai/tool/polyline.py

@@ -168,6 +168,7 @@ class Polyline(bonsai.core.tool.Polyline):
         distance = (mouse_vector - last_point).length
         if distance < 0:
             return
+        angle, orientation_angle, angle_round_threshold = None, None, None
         if distance > 0:
             angle = tool.Cad.angle_3_vectors(
                 second_to_last_point, last_point, mouse_vector, new_angle=None, degrees=True
@@ -188,6 +189,7 @@ class Polyline(bonsai.core.tool.Polyline):
             angle = 0
             orientation_angle = 0
         if input_ui:
+            assert angle is not None and orientation_angle is not None and angle_round_threshold is not None
             if should_round:
                 angle_snap = tool.Snap.get_angle_snap_value(context)
                 angle = angle_snap * round(angle / angle_snap) if distance < angle_round_threshold else angle

src/bonsai/bonsai/tool/project.py

@@ -370,18 +370,21 @@ class Project(bonsai.core.tool.Project):
         props = cls.get_project_props()
         active_library_breadcrumb = props.get_active_library_breadcrumb()
         change_back = False
+        breadcrumb = None
         if active_library_breadcrumb:
             name = active_library_breadcrumb.name
             breadcrumb_type = active_library_breadcrumb.breadcrumb_type
             library_id = active_library_breadcrumb.library_id
+            breadcrumb = (name, breadcrumb_type, library_id)
             change_back = True
 
         bpy.ops.bim.rewind_library()
         if change_back:
+            assert breadcrumb
             bpy.ops.bim.change_library_element(
-                element_name=name,
-                breadcrumb_type=breadcrumb_type,
-                library_id=library_id,
+                element_name=breadcrumb[0],
+                breadcrumb_type=breadcrumb[1],
+                library_id=breadcrumb[2],
             )
 
     @classmethod

src/bonsai/bonsai/tool/pset.py

@@ -124,6 +124,9 @@ class Pset(bonsai.core.tool.Pset):
             return bpy.context.scene.GroupPsetProperties
         elif obj_type == "Zone":
             return bpy.context.scene.ZonePsetProperties
+        elif obj_type == "Cost":
+            # No psets for cost items currently.
+            assert False, obj_type
         assert_never(obj_type)
 
     @classmethod

src/bonsai/bonsai/tool/raycast.py

@@ -232,7 +232,7 @@ class Raycast(bonsai.core.tool.Raycast):
         return final_2d, v2
 
     @classmethod
-    def intersect_mouse_2d_bounding_box(cls, mouse_pos: tuple[int, int], bbox: list[float, float, float, float]):
+    def intersect_mouse_2d_bounding_box(cls, mouse_pos: tuple[int, int], bbox: list[float]):
         x, y = mouse_pos
         xmin, xmax, ymin, ymax = bbox
 

src/bonsai/bonsai/tool/search.py

@@ -505,6 +505,8 @@ class Search(bonsai.core.tool.Search):
                 (0.773, 0.922, 0.816),
                 (0.871, 0.957, 0.894),
             ]
+        else:
+            assert False, theme
 
         if value < min_val:
             value = min_val
@@ -574,8 +576,10 @@ class ImportFilterQueryTransformer(lark.Transformer):
         new = self.filter_groups.add()
         global_ids = []
         is_first_group = len(self.filter_groups) == 1
+        new2 = None
         for filter_index, arg in enumerate(args):
             if arg["type"] == "instance" and global_ids:
+                assert new2
                 if "bpy.data.texts" in new2.value:
                     data_name = new2.value.split("bpy.data.texts")[1][2:-2]
                     bpy.data.texts[data_name].write("," + arg["value"])

src/bonsai/bonsai/tool/sequence.py

@@ -23,7 +23,7 @@ import re
 from collections.abc import Iterable
 from datetime import datetime
 from datetime import time as datetime_time
-from typing import TYPE_CHECKING, Any, Literal, Optional, Union
+from typing import TYPE_CHECKING, Any, Literal, Optional, Union, assert_never
 
 import bpy
 import ifcopenshell
@@ -1127,7 +1127,8 @@ class Sequence(bonsai.core.tool.Sequence):
 
     @classmethod
     def load_default_animation_color_scheme(cls):
-        groups = {
+        GroupType = Literal["CREATION", "OPERATION", "MOVEMENT_TO", "DESTRUCTION", "MOVEMENT_FROM", "USERDEFINED"]
+        groups: dict[GroupType, dict[str, Any]] = {
             "CREATION": {
                 "PredefinedType": ["CONSTRUCTION", "INSTALLATION"],
                 "Color": (0.0, 1.0, 0.0),
@@ -1158,15 +1159,17 @@ class Sequence(bonsai.core.tool.Sequence):
         props.task_input_colors.clear()
         for group, data in groups.items():
             for predefined_type in data["PredefinedType"]:
-                if group in ["CREATION", "OPERATION", "MOVEMENT_TO"]:
+                if group in ("CREATION", "OPERATION", "MOVEMENT_TO"):
                     predefined_type_item = props.task_output_colors.add()
-                elif group in ["MOVEMENT_FROM"]:
+                elif group in ("MOVEMENT_FROM",):
                     predefined_type_item = props.task_input_colors.add()
-                elif group in ["USERDEFINED", "DESTRUCTION"]:
+                elif group in ("USERDEFINED", "DESTRUCTION"):
                     predefined_type_item = props.task_input_colors.add()
                     predefined_type_item2 = props.task_output_colors.add()
                     predefined_type_item2.name = predefined_type
                     predefined_type_item2.color = data["Color"]
+                else:
+                    assert_never(group)
                 # TO DO: consider cases where users confuses inputs and outputs
                 predefined_type_item.name = predefined_type
                 predefined_type_item.color = data["Color"]

src/bonsai/bonsai/tool/snap.py

@@ -225,6 +225,7 @@ class Snap(bonsai.core.tool.Snap):
         # Get axis that are closer than the stick factor threshold
         elegible_axis = []
 
+        axis = None
         for axis in snap_axis:
             if not axis:
                 continue
@@ -326,6 +327,7 @@ class Snap(bonsai.core.tool.Snap):
         detected_snaps: list[dict[str, Any]] = []
 
         def select_plane_method():
+            plane_origin, plane_normal = None, None
             if not last_polyline_point:
                 plane_origin = Vector((0, 0, 0))
                 plane_normal = Vector((0, 0, 1))
@@ -357,6 +359,7 @@ class Snap(bonsai.core.tool.Snap):
                     plane_origin = Vector((last_polyline_point.x, last_polyline_point.y, last_polyline_point.z))
                 plane_normal = Vector((1, 0, 0))
 
+            assert plane_origin and plane_normal
             plane_normal = tool.Polyline.use_transform_orientations(plane_normal)
             return plane_origin, plane_normal
 
@@ -583,6 +586,7 @@ class Snap(bonsai.core.tool.Snap):
 
         snaps_by_group = filter_snapping_points_by_group(detected_snaps)
         edges = []  # Get edges to create edge-intersection snap
+        axis_start, axis_end = ..., ...
         for snapping_point in snaps_by_group:
             if snapping_point["group"] in {"Polyline", "Measure", "Wireframe", "Object"}:
                 if snapping_point["type"] == "Edge":
@@ -607,6 +611,7 @@ class Snap(bonsai.core.tool.Snap):
                 if point["type"] == "Axis":
                     if ordered_snaps[0]["type"] not in {"Axis", "Plane"}:
                         obj = ordered_snaps[0]["object"]
+                        assert axis_start is not ... and axis_end is not ...
                         mixed_snap = cls.mix_snap_and_axis(ordered_snaps[0], axis_start, axis_end)
                         for mixed_point in mixed_snap:
                             snap_point = {

src/bonsai/bonsai/tool/spatial.py

@@ -304,12 +304,14 @@ class Spatial(bonsai.core.tool.Spatial):
 
             while True:
                 has_parent = None
+                new_current_results = None
                 for key in current_results:
                     if flat_key.startswith(key):
                         has_parent = True
                         new_current_results = current_results[key]["children"]
                         break
                 if has_parent:
+                    assert new_current_results is not None
                     current_results = new_current_results
                 else:
                     break
@@ -978,19 +980,24 @@ class Spatial(bonsai.core.tool.Spatial):
         interiors_list = []
 
         if union_geom.geom_type == "MultiPolygon":
+            poly = None
             for poly in union_geom.geoms:
                 interiors_list = cls.get_poly_valid_interior_list(
                     poly=poly, min_area=min_area, interiors_list=interiors_list
                 )
 
+            assert poly
             new_poly = Polygon(poly.exterior.coords, holes=interiors_list)
 
-        if union_geom.geom_type == "Polygon":
+        elif union_geom.geom_type == "Polygon":
             interiors_list = cls.get_poly_valid_interior_list(
                 poly=union_geom, min_area=min_area, interiors_list=interiors_list
             )
             new_poly = Polygon(union_geom.exterior.coords, holes=interiors_list)
 
+        else:
+            assert False, union_geom.geom_type
+
         return new_poly
 
     @classmethod

src/bonsai/bonsai/tool/style.py

@@ -360,6 +360,10 @@ class Style(bonsai.core.tool.Style):
         material_output = tool.Blender.get_material_node(obj, "OUTPUT_MATERIAL", {"is_active_output": True})
         surface_output = get_input_node(material_output, "Surface")
 
+        # TODO: this variable is not really needed,
+        # just workaround a for ty issue detecting unresolved refs.
+        bsdf = None
+
         if surface_output and surface_output.type == "MIX_SHADER":
             mix_shader = surface_output
             if (
@@ -388,6 +392,7 @@ class Style(bonsai.core.tool.Style):
                 and (bsdf := get_input_node(surface_output, input_index=1, of_type="BSDF_PRINCIPLED"))
             )
         ):
+            assert bsdf
             report(f"Because of {BLUE}BSDF_PRINCIPLED{R} node reflectance method identified as {BLUE}PHYSICAL{R}")
             attributes["ReflectanceMethod"] = "NOTDEFINED" if tool.Ifc.get_schema() != "IFC4X3" else "PHYSICAL"
 

src/bonsai/docs/guides/development/installation.rst

@@ -24,7 +24,7 @@ Blender versions:
 - 64-bit MacOS Intel (``macos-x64``)
 - 64-bit MacOS Silicon (``macos-arm64``)
 - 64-bit Windows (``windows-x64``)
-- Blender 4.3, 4.4, or 4.5 with Python 3.11
+- Blender 5.1 or 5.2 with Python 3.13
 
 Developer builds may exist for different versions of Python but there will be
 no guarantee of the uptime or stability of these builds.

src/bonsai/docs/guides/development/maintenance.rst

@@ -44,8 +44,6 @@ When a new Blender version is released and supported:
 
    * - File
      - What to update
-   * - ``.github/workflows/ci-bonsai.yml``
-     - ``pyver`` matrix
    * - ``.github/workflows/ci-bonsai-daily.yml``
      - Blender download URL
 
@@ -61,6 +59,10 @@ When Blender ships with a new Python version:
      - What to update
    * - ``.github/workflows/ci-lint.yaml``
      - ``MIN_BLENDER_PY_VERSION``
+   * - ``.github/workflows/ci-bonsai.yml``
+     - ``pyver`` matrix
+   * - ``.github/workflows/ci-bonsai-daily.yml``
+     - ``pyver`` matrix
    * - ``.github/scripts/publish-bonsai-releases.py``
      - ``CURRENT_PYTHON_VERSION``
    * - ``src/bonsai/Makefile``

src/bonsai/pyproject.toml

@@ -18,12 +18,6 @@ dependencies = [
     "ifcopenshell",
 ]
 
-[project.optional-dependencies]
-dev = [
-  "pytest-blender",
-  "pytest-bdd",
-]
-
 [project.urls]
 Homepage = "http://bonsaibim.org"
 Documentation = "https://docs.bonsaibim.org"

src/bonsai/requirements-dev.txt

@@ -0,0 +1,3 @@
+pytest
+pytest-blender
+pytest-bdd

src/bonsai/scripts/bonsai_translations.py

@@ -216,6 +216,7 @@ def update_translations_from_po(po_directory: Path, translations_module: Path):
 
 
 if BPY_IS_LOADED:
+    import bpy
 
     class SetupTranslationUI(bpy.types.Operator):
         bl_idname = "bim.setup_translation_ui"

src/bonsai/scripts/classifications/brick_classifiction.py

@@ -82,6 +82,7 @@ class Generator:
                 }
                 """.replace("{entity}", location.split("#")[-1]))
             # filter parents for the brick entity
+            parent = None
             for row in query:
                 parent = row.get("parent").toPython()
                 if "brickschema.org" in parent and parent in references.keys():

src/bonsai/scripts/dev_environment.py

@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 """Setup Bonsai Development Environment.
 
 Script links existing Bonsai installation to the provided IfcOpenShell repository.
@@ -78,7 +79,8 @@ BONSAI_PATH = find_bonsai_path()
 # ---------------------------
 
 # Never changed by user.
-PYTHON_VERSION = "3.13" if BLENDER_VERSION == "5.1" else "3.11"
+BLENDER_VERSION_INT = tuple(map(int, BLENDER_VERSION.split(".")))
+PYTHON_VERSION = "3.13" if BLENDER_VERSION_INT >= (5, 1) else "3.11"
 PACKAGE_PATH = BLENDER_PATH / rf"extensions/.local/lib/python{PYTHON_VERSION}/site-packages"
 
 

src/bonsai/scripts/dxf2ifc.py

@@ -16,20 +16,26 @@
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
 
+import argparse
+
 import ezdxf
 import ifcopenshell
 import ifcopenshell.guid
 
 
 class Dxf2Ifc:
+    def __init__(self, dxf_path, outfile):
+        self.dxf_path = dxf_path
+        self.outfile = outfile
+
     def execute(self):
         self.create_ifc_file()
-        doc = ezdxf.readfile("input.dxf")
+        doc = ezdxf.readfile(self.dxf_path)
         model = doc.modelspace()
         products = []
         for entity in model:
             print(entity)
-            if entity.get_mode() == "AcDbPolyFaceMesh":
+            if entity.dxftype() == "POLYLINE" and entity.is_poly_face_mesh:
                 ifc_faces = []
                 for face in entity.faces():
                     ifc_faces.append(
@@ -67,15 +73,18 @@ class Dxf2Ifc:
                             "Name": entity.dxf.layer,
                             "ObjectPlacement": self.placement,
                             "Representation": representation,
-                        }
+                        },
                     )
                 )
             else:
-                print("Not yet implemented")
-        self.file.createIfcRelContainedInSpatialStructure(
-            ifcopenshell.guid.new(), None, None, None, products, self.site
-        )
-        self.file.write("test.ifc")
+                print(f"Skipping unsupported entity: {entity.dxftype()}")
+        if products:
+            self.file.createIfcRelContainedInSpatialStructure(
+                ifcopenshell.guid.new(), None, None, None, products, self.site
+            )
+        else:
+            print("No AcDbPolyFaceMesh entities found, writing an empty IFC")
+        self.file.write(self.outfile)
 
     def create_ifc_file(self):
         self.file = ifcopenshell.file()
@@ -97,14 +106,20 @@ class Dxf2Ifc:
                 "Name": "DXF Conversion",
                 "RepresentationContexts": [self.context],
                 "UnitsInContext": units,
-            }
+            },
         )
         self.site = self.file.create_entity(
             "IfcSite",
-            **{"GlobalId": ifcopenshell.guid.new(), "Name": "DXF Conversion Site", "ObjectPlacement": self.placement}
+            **{"GlobalId": ifcopenshell.guid.new(), "Name": "DXF Conversion Site", "ObjectPlacement": self.placement},
         )
         self.file.createIfcRelAggregates(ifcopenshell.guid.new(), None, None, None, self.project, [self.site])
 
 
-dxf2ifc = Dxf2Ifc()
-dxf2ifc.execute()
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Converts DXF polyface meshes (AcDbPolyFaceMesh) to an IFC")
+    parser.add_argument("dxf", type=str, help="The input DXF file")
+    parser.add_argument("-o", "--output", type=str, help="The output IFC file", default="out.ifc")
+    args = parser.parse_args()
+
+    dxf2ifc = Dxf2Ifc(args.dxf, args.output)
+    dxf2ifc.execute()

src/bonsai/scripts/generate_furniture_library.py

@@ -1036,6 +1036,7 @@ class LibraryGenerator:
             seat_width_offset = 0.7 * width / 2 if cistern_depth else width / 2
             seat_start_width_offset = 0.6 * width
 
+            cistern_3d = None
             if cistern_height:
                 cistern = builder.rectangle(size=V(width, cistern_depth), position=shift_to_center)
                 cistern_3d = ifcopenshell.util.element.copy_deep(self.file, cistern)
@@ -1118,6 +1119,7 @@ class LibraryGenerator:
 
             # cistern
             if cistern_height:
+                assert cistern_3d
                 cistern_3d = builder.extrude(
                     cistern_3d, cistern_height + seat_level / 2, position=V(0, 0, seat_level / 2)
                 )

src/bonsai/scripts/generate_steel_profiles_library.py

@@ -143,6 +143,7 @@ class LibraryGenerator:
                     if "unused" in ifc_params:
                         del ifc_params["unused"]
 
+                    profiles_gap = ...
                     if prof_type == "profile_hollow*_square":
                         ifc_params["YDim"] = ifc_params["XDim"]
                     elif ifc_profile_name == "IfcCircleHollowProfileDef":
@@ -160,6 +161,7 @@ class LibraryGenerator:
                     profile = self.file.create_entity(ifc_profile_name, ProfileName=prof_name, ProfileType="AREA", **ifc_params)
 
                     if prof_type == "profile_l*lbeam_2l":
+                        assert profiles_gap is not ...
                         profile.ProfileName = None # to avoid name confusion
                         mode = "SLBB" if prof_name.endswith("_SLBB") else "LLBB"
                         profile = self.create_double_l_profile(profile, prof_name, profiles_gap, mode)

src/bonsai/test/bim/module/model/test_profile_decorator_duplicate_loop.py

@@ -0,0 +1,141 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2026
+#
+# This file is part of Bonsai.
+#
+# Bonsai is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Bonsai is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
+#
+# This file was generated with the assistance of an AI coding tool.
+
+"""Regression tests for ``ProfileDecorator``'s ``_connected_components`` helper.
+
+Duplicating a circle/arc void's loop in Edit Mode (Tab, Tab, select the
+loop, Shift+D) copies the ``IFCARCINDEX``/``IFCCIRCLE`` vertex-group
+weights onto the new geometry, since Blender's mesh duplicate never
+allocates a new vertex group. Before this fix, ``ProfileDecorator``
+grouped arc/circle vertices by group index alone, so the duplicate's
+vertices piled into the same entry as the source loop's, failing the
+"exactly 2/3 verts" check and silently dropping *both* loops from the
+decorator until the mesh was re-imported (e.g. by leaving and re-entering
+Edit Mode). ``_connected_components`` splits each group's vertices back
+into their connected loops so a duplicate is drawn immediately, see #6944."""
+
+import bmesh
+import bpy
+import pytest
+
+from bonsai.bim.module.model.decorator import _connected_components
+
+pytestmark = pytest.mark.model
+
+
+def _bm_with_groups(verts, edges, groups):
+    """Build a standalone bmesh with a deform layer, and populate ``groups``:
+    a list of (group_index, [vert_indices]) pairs, mirroring how
+    ``tool.Model.import_profile``/``convert_curve_to_mesh`` assign one
+    vertex group per circle/arc loop."""
+    bm = bmesh.new()
+    deform_layer = bm.verts.layers.deform.new()
+    bm_verts = [bm.verts.new(v) for v in verts]
+    bm.verts.ensure_lookup_table()
+    for a, b in edges:
+        bm.edges.new((bm_verts[a], bm_verts[b]))
+    bm.verts.ensure_lookup_table()
+    bm_verts = list(bm.verts)
+    for group_index, vert_indices in groups:
+        for vi in vert_indices:
+            bm_verts[vi][deform_layer][group_index] = 1.0
+    return bm, bm_verts, deform_layer
+
+
+def _group_dict(bm_verts, deform_layer, group_index, vert_indices):
+    return {group_index: [bm_verts[i] for i in vert_indices]}
+
+
+def test_single_circle_loop_is_one_component():
+    # A circle is exactly 2 verts joined by 1 edge (tool.Model.convert_curve_to_mesh).
+    bm, bm_verts, deform_layer = _bm_with_groups(
+        verts=[(0, -1, 0), (0, 1, 0)],
+        edges=[(0, 1)],
+        groups=[(0, [0, 1])],
+    )
+    circles = _group_dict(bm_verts, deform_layer, 0, [0, 1])
+    components = _connected_components(circles)
+    assert len(components) == 1
+    assert len(components[0]) == 2
+    bm.free()
+
+
+def test_single_arc_loop_is_one_component():
+    # An arc is exactly 3 verts: endpoint-midpoint-endpoint (2 edges).
+    bm, bm_verts, deform_layer = _bm_with_groups(
+        verts=[(0, -1, 0), (0, 0, 0.3), (0, 1, 0)],
+        edges=[(0, 1), (1, 2)],
+        groups=[(0, [0, 1, 2])],
+    )
+    arcs = _group_dict(bm_verts, deform_layer, 0, [0, 1, 2])
+    components = _connected_components(arcs)
+    assert len(components) == 1
+    assert len(components[0]) == 3
+    bm.free()
+
+
+def test_duplicated_circle_loop_splits_into_two_components():
+    # Duplicating verts 0-1 (Shift+D) yields verts 2-3, connected to each
+    # other but NOT to the source loop, while keeping the same group index
+    # (0) -- exactly what bmesh.ops.duplicate produces mid Edit-Mode.
+    bm, bm_verts, deform_layer = _bm_with_groups(
+        verts=[(0, -1, 0), (0, 1, 0), (5, -1, 0), (5, 1, 0)],
+        edges=[(0, 1), (2, 3)],
+        groups=[(0, [0, 1, 2, 3])],
+    )
+    circles = _group_dict(bm_verts, deform_layer, 0, [0, 1, 2, 3])
+    components = _connected_components(circles)
+    assert len(components) == 2
+    assert sorted(len(c) for c in components) == [2, 2]
+    bm.free()
+
+
+def test_duplicated_arc_loop_splits_into_two_components():
+    bm, bm_verts, deform_layer = _bm_with_groups(
+        verts=[(0, -1, 0), (0, 0, 0.3), (0, 1, 0), (5, -1, 0), (5, 0, 0.3), (5, 1, 0)],
+        edges=[(0, 1), (1, 2), (3, 4), (4, 5)],
+        groups=[(0, [0, 1, 2, 3, 4, 5])],
+    )
+    arcs = _group_dict(bm_verts, deform_layer, 0, [0, 1, 2, 3, 4, 5])
+    components = _connected_components(arcs)
+    assert len(components) == 2
+    assert sorted(len(c) for c in components) == [3, 3]
+    bm.free()
+
+
+def test_distinct_circle_groups_stay_separate_and_correctly_sized():
+    # Multiple genuinely different circles (distinct group indices) must
+    # each still resolve to their own single 2-vert component.
+    verts = []
+    edges = []
+    groups = []
+    for i in range(5):
+        base = len(verts)
+        verts += [(i * 3, -1, 0), (i * 3, 1, 0)]
+        edges.append((base, base + 1))
+        groups.append((i, [base, base + 1]))
+    bm, bm_verts, deform_layer = _bm_with_groups(verts, edges, groups)
+    circles = {}
+    for group_index, vert_indices in groups:
+        circles[group_index] = [bm_verts[i] for i in vert_indices]
+    components = _connected_components(circles)
+    assert len(components) == 5
+    assert all(len(c) == 2 for c in components)
+    bm.free()

src/bonsai/test/bim/test_feature.py

@@ -30,7 +30,7 @@ from collections.abc import Generator
 from inspect import signature
 from math import radians
 from pathlib import Path
-from typing import Any, Union
+from typing import Any, Union, cast
 
 import bpy
 import ifcopenshell
@@ -140,7 +140,7 @@ class PanelSpy:
             else:
                 props = kwargs.get("data")
                 name = kwargs.get("property")
-            props: bpy.types.bpy_struct
+            props = cast(bpy.types.bpy_struct, props)
             text = kwargs.get("text", props.bl_rna.properties[name].name)
             icon = kwargs.get("icon", None)
             prop_type = props.bl_rna.properties[name].type