Fix workspace.py is_manual_reference block ordering for build compatibility

Move is_manual_reference UI block to before _DIMENSION_TYPES to match the
position established by PR #7965's conflict resolution already present in
the build. The prior merge fix (66fcad84e3) placed it after _DIMENSION_TYPES,
causing a 3-way merge conflict when the build's #7965 has it before.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/scripts/publish-bonsai-releases.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env -S uv run
+# /// script
+# dependencies = [
+#     "PyGithub",
+#     "requests",
+# ]
+# ///
+
+import os
+from pathlib import Path
+
+import requests
+from github import Github
+from github.GitReleaseAsset import GitReleaseAsset
+
+EXTENSION_ID = "bonsai"
+CURRENT_PYTHON_VERSION = "py313"
+CURRENT_PLATFORMS = ["linux-x64", "macos-arm64", "windows-x64"]
+
+
+def publish_asset(asset: GitReleaseAsset, token: str, repo_root: Path) -> None:
+    """
+    Publish an asset to Blender Extensions.
+    Reference: https://extensions.blender.org/api/v1/swagger
+    """
+    temp_path = repo_root / asset.name
+
+    response = requests.get(asset.browser_download_url)
+    response.raise_for_status()
+    temp_path.write_bytes(response.content)
+
+    url = f"https://extensions.blender.org/api/v1/extensions/{EXTENSION_ID}/versions/upload/"
+    headers = {"Authorization": f"Bearer {token}"}
+
+    files = {"version_file": temp_path.read_bytes()}
+    response = requests.post(url, headers=headers, files=files)
+    response.raise_for_status()
+
+    temp_path.unlink()
+
+    print(f"✓ Published {asset.name}")
+
+
+def main() -> None:
+    token = os.getenv("BLENDER_EXTENSIONS_TOKEN")
+    if not token:
+        raise Exception("BLENDER_EXTENSIONS_TOKEN environment variable not set")
+
+    # Get the repository root
+    repo_root = Path(__file__).parent.parent.parent
+
+    # Read VERSION file
+    version_file = repo_root / "VERSION"
+    version = version_file.read_text().strip()
+
+    print(f"Current VERSION: {version}")
+
+    tag_name = f"bonsai-{version}"
+
+    # Get release from GitHub
+    gh = Github()
+    gh_repo = gh.get_repo("IfcOpenShell/IfcOpenShell")
+    release = gh_repo.get_release(tag_name)
+
+    assets = release.get_assets()
+
+    asset_platform_map: dict[str, tuple[GitReleaseAsset, str]] = {}
+    for asset in assets:
+        if CURRENT_PYTHON_VERSION not in asset.name:
+            continue
+        for platform in CURRENT_PLATFORMS:
+            if platform in asset.name:
+                asset_platform_map[asset.name] = (asset, platform)
+                break
+
+    if len(asset_platform_map) != len(CURRENT_PLATFORMS):
+        found_platforms = {platform for _, (_, platform) in asset_platform_map.items()}
+        missing_platforms = set(CURRENT_PLATFORMS) - found_platforms
+        raise Exception(
+            f"Expected {len(CURRENT_PLATFORMS)} assets but found {len(asset_platform_map)}. "
+            f"Missing: {', '.join(sorted(missing_platforms))}"
+        )
+
+    print("\nRelease assets:")
+    for asset_name in sorted(asset_platform_map.keys()):
+        print(f"- {asset_name}")
+
+    # https://extensions.blender.org/api/v1/swagger
+    print("\nPublishing assets to Blender Extensions:")
+    for asset_name, (asset, platform) in asset_platform_map.items():
+        publish_asset(asset, token, repo_root)
+
+
+if __name__ == "__main__":
+    main()

.github/workflows/build_osx.yml

@@ -53,7 +53,7 @@ jobs:
           python ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: mac-${{ matrix.arch }}
 

.github/workflows/build_pyodide.yml

@@ -29,7 +29,7 @@ jobs:
           python ../IfcOpenShell/nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}
 

.github/workflows/build_rocky.yml

@@ -9,6 +9,13 @@ jobs:
     container: rockylinux:9
 
     steps:
+      - name: Set up uv
+        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
+
+      - name: Install Python
+        # Installs latest Python version so it's preferred by uv over Rocky's system Python.
+        run: uv python install
+
       - name: Install Dependencies
         run: |
           dnf update -y
@@ -17,7 +24,6 @@ jobs:
                          sqlite-devel bzip2-devel zlib-devel openssl-devel xz-devel      \
                          readline-devel ncurses-devel libffi-devel libuuid-devel git-lfs \
                          findutils xz byacc
-          python3 -m pip install typing_extensions
           git config --global --add safe.directory '*'
 
       - name: Install aws cli
@@ -45,10 +51,10 @@ jobs:
       - name: Unpack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py unpack
+          uv run ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}-rockylinux9
 
@@ -56,7 +62,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release python3 ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
+          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release uv run ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
 
       - name: Upload Build Logs
         if: always()
@@ -71,7 +77,7 @@ jobs:
       - name: Pack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py pack
+          uv run ../nix/cache_dependencies.py pack
 
       - name: Commit and Push Changes to Build Repository
         run: |

.github/workflows/build_rocky_arm.yml

@@ -9,6 +9,13 @@ jobs:
     container: arm64v8/rockylinux:9
 
     steps:
+      - name: Set up uv
+        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
+
+      - name: Install Python
+        # Installs latest Python version so it's preferred by uv over Rocky's system Python.
+        run: uv python install
+
       - name: Install Dependencies
         run: |
           dnf update -y
@@ -17,7 +24,6 @@ jobs:
                          sqlite-devel bzip2-devel zlib-devel openssl-devel xz-devel      \
                          readline-devel ncurses-devel libffi-devel libuuid-devel git-lfs \
                          findutils xz byacc
-          python3 -m pip install typing_extensions
           git config --global --add safe.directory '*'
 
       - name: Install aws cli
@@ -45,10 +51,10 @@ jobs:
       - name: Unpack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py unpack
+          uv run ../nix/cache_dependencies.py unpack
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}-rockylinux9
 
@@ -56,7 +62,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release python3 ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
+          CXXFLAGS="-O3" CFLAGS="-O3 ${DARWIN_C_SOURCE}" ADD_COMMIT_SHA=1 BUILD_CFG=Release uv run ./nix/build-all.py -v --diskcleanup 2>&1 | tee build.log
 
       - name: Upload Build Logs
         if: always()
@@ -71,7 +77,7 @@ jobs:
       - name: Pack Dependencies
         run: |
           cd build
-          python3 ../nix/cache_dependencies.py pack
+          uv run ../nix/cache_dependencies.py pack
 
       - name: Commit and Push Changes to Build Repository
         run: |

.github/workflows/build_win.yml

@@ -52,7 +52,7 @@ jobs:
           }
 
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: win-${{ matrix.arch }}
           # Windows ccache needs ~1GB

.github/workflows/ci-ifcopenshell-docker.yml

@@ -35,7 +35,7 @@ jobs:
 
     -
       name: ccache
-      uses: hendrikmuhs/ccache-action@v1.2.22
+      uses: hendrikmuhs/ccache-action@v1.2.23
 
     - 
       name: Build ifcopenshell

.github/workflows/ci-lint.yaml

@@ -95,8 +95,7 @@ jobs:
             echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
           }
 
-          run_check poe ruff-main
-          run_check poe ruff-old
+          run_check poe ruff
 
           exit $ERROR
         continue-on-error: true

.github/workflows/ci.yml

@@ -79,7 +79,7 @@ jobs:
           libhdf5-dev libcgal-dev libeigen3-dev
           
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2.22
+        uses: hendrikmuhs/ccache-action@v1.2.23
         with:
           key: ubuntu-22.04-${{ runner.arch }}
 

.github/workflows/publish-bonsai-releases.yml

@@ -0,0 +1,16 @@
+name: Publish Bonsai Releases
+
+on:
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: astral-sh/setup-uv@v7
+
+      - run: uv run .github/scripts/publish-bonsai-releases.py
+        env:
+          BLENDER_EXTENSIONS_TOKEN: ${{ secrets.BLENDER_EXTENSIONS_TOKEN }}

nix/build-all.py

@@ -1,4 +1,6 @@
 #!/usr/bin/python
+# /// script
+# ///
 ###############################################################################
 #                                                                             #
 # This file is part of IfcOpenShell.                                          #
@@ -126,13 +128,7 @@ from collections.abc import Generator, Sequence
 from pathlib import Path
 from urllib.request import urlretrieve
 
-try:
-    from typing import Literal, Union
-except:
-    # python 3.6 compatibility for rocky 8
-    from typing import Union
-
-    from typing_extensions import Literal
+from typing import Literal, Union
 
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.INFO)

nix/cache_dependencies.py

@@ -1,3 +1,5 @@
+# /// script
+# ///
 """
 Cache built dependencies for builds.
 

pyodide/build_pyodide.sh

@@ -1,6 +1,11 @@
 #!/usr/bin/bash
 set -ex
 
+PYODIDE_VERSION=0.29.3
+PYODIDE_BUILD_VERSION=0.33.0
+PYODIDE_XBUILDENV_ROOT="${HOME}/.cache/.pyodide-xbuildenv-${PYODIDE_BUILD_VERSION}"
+PYODIDE_XBUILDENV="${PYODIDE_XBUILDENV_ROOT}/${PYODIDE_VERSION}"
+
 # Script is assuming that it will be possible to execute it multiple times
 # therefore we're clearing venv each time and ignoring existing 'emsdk' folder.
 
@@ -11,14 +16,15 @@ source .venv/bin/activate
 
 # Install pyodide cross build environment.
 # Instructions: https://pyodide.org/en/stable/development/building-packages.html
-uv pip install pyodide-build
+uv pip install "pyodide-build==${PYODIDE_BUILD_VERSION}"
 # `uv run` is required, so xbuildenv would skip using `pip`.
-uv run pyodide xbuildenv install
+uv run pyodide xbuildenv install "${PYODIDE_VERSION}"
 uv run pyodide xbuildenv install-emscripten
 
-EMSDK_ROOT=$(pyodide config get emscripten_dir)
-source ${EMSDK_ROOT}/emsdk_env.sh
+EMSDK_ROOT="${PYODIDE_XBUILDENV}/emsdk"
+source "${EMSDK_ROOT}/emsdk_env.sh"
 which emcc
+emcc --version
 
 mkdir -p packages/ifcopenshell
 VERSION=`cat IfcOpenShell/VERSION`

pyproject.toml

@@ -3,9 +3,9 @@ name = "IfcOpenShell"
 version = "0.0.0"
 dependencies = [
     "black==26.3.1",
-    "ruff==0.15.9",
+    "ruff==0.15.12",
     "poethepoet",
-    "ty==0.0.29",
+    "ty==0.0.32",
     "gersemi==0.26.1",
 ]
 
@@ -215,10 +215,7 @@ exclude = [
 
 [tool.poe.tasks]
 
-ruff-main = "ruff check --extend-exclude nix/build-all.py"
-# It's actually Python 3.6, but ruff only supports 3.7+, but it should do.
-ruff-old = "ruff check nix/build-all.py --target-version py37"
-ruff.sequence = ["ruff-main", "ruff-old"]
+ruff = "ruff check"
 
 black = "black ."
 
@@ -238,7 +235,7 @@ ty-venv-ios.sequence = [
     {cmd = "uv pip install -r src/ifcopenshell-python/type-check-requirements.txt --python=src/ifcopenshell-python/.venv"},
 ]
 
-format.sequence = ["black", "ruff-main", "ruff-old"]
+format.sequence = ["black", "ruff"]
 
 cmake-format = "gersemi . --in-place"
 

src/bonsai/Makefile

@@ -17,8 +17,8 @@
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
 
 SHELL := sh
-PYTHON:=python3.11
-PIP:=pip3.11
+PYTHON:=python3
+PIP:=pip3
 PATCH:=patch
 SED:=sed -i
 VENV_ACTIVATE:=bin/activate

src/bonsai/bonsai/bim/data/fonts/LICENSE

@@ -0,0 +1,96 @@
+Copyright (c) 2011-2012, Nikita Volchenkov (<nikitavolchenkov@gmail.com>),
+with Reserved Font Name OpenGost Type B.
+
+Copyright (c) 2012, Valek Filippov (<frob@gnome.org>).
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

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

@@ -5,7 +5,7 @@ FILE_NAME('Psets_BBIM_Annotation.ifc','2020-01-01T00:00:00',$,$,'Psets_BBIM_Anno
 FILE_SCHEMA(('IFC4'));
 ENDSEC;
 DATA;
-#1=IFCPROPERTYSETTEMPLATE('3VuPUwdCD2Qx3XDDRs0R1N',$,'EPset_Annotation','',.PSET_TYPEDRIVENOVERRIDE.,'IfcAnnotation,IfcTypeProduct',(#4,#33,#29,#32,#3,#2));
+#1=IFCPROPERTYSETTEMPLATE('3VuPUwdCD2Qx3XDDRs0R1N',$,'EPset_Annotation','',.PSET_TYPEDRIVENOVERRIDE.,'IfcAnnotation,IfcTypeProduct',(#4,#33,#29,#32,#3,#2,#41,#42));
 #2=IFCSIMPLEPROPERTYTEMPLATE('2P7JN79n96Q9pElZ83LKe4',$,'ZIndex','',.P_SINGLEVALUE.,'IfcInteger',$,$,$,$,$,.READWRITE.);
 #3=IFCSIMPLEPROPERTYTEMPLATE('1Wpx_r2xj1_9w5JpI0QRJy',$,'Symbol','',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
 #4=IFCSIMPLEPROPERTYTEMPLATE('3q0oxMUKP47vZ4jnyG$dDb',$,'Classes','Classes separated by spaces that end up in classes for this element in svg. Can be used to specify the text font size: small - 1.8mm; regular - 2.5mm; large - 3.5mm; header - 5mm; title - 7mm. By default regular size is used.',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
@@ -28,7 +28,7 @@ DATA;
 #21=IFCSIMPLEPROPERTYTEMPLATE('1UDakJ5_f7kBhggNSW4$h5',$,'SymbolsPath','Default symbols SVG',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
 #22=IFCSIMPLEPROPERTYTEMPLATE('0d53LEtgLDQxnv__NfgH7i',$,'PatternsPath','Default patterns SVG',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
 #23=IFCSIMPLEPROPERTYTEMPLATE('26qFNMv7nCHgU6Jd7Anga5',$,'ShadingStylesPath','Default shading styles',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
-#24=IFCPROPERTYSETTEMPLATE('0I9merLinF5Ap$aZwaclgm',$,'BBIM_Dimension','',.PSET_TYPEDRIVENOVERRIDE.,'IfcAnnotation/DIMENSION,IfcAnnotation/RADIUS,IfcAnnotation/DIAMETER,IfcTypeProduct',(#25,#26,#27,#28,#30));
+#24=IFCPROPERTYSETTEMPLATE('0I9merLinF5Ap$aZwaclgm',$,'BBIM_Dimension','',.PSET_TYPEDRIVENOVERRIDE.,'IfcAnnotation/DIMENSION,IfcAnnotation/RADIUS,IfcAnnotation/DIAMETER,IfcAnnotation/ANGLE,IfcAnnotation/PLAN_LEVEL,IfcAnnotation/SECTION_LEVEL,IfcTypeProduct',(#25,#26,#35,#36,#27,#28,#30,#34,#37,#38,#39,#40));
 #25=IFCSIMPLEPROPERTYTEMPLATE('1rL2AbQsXD8RbpoWH5pYOV',$,'ShowDescriptionOnly','Hide the measurement values and show only annotation description',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
 #26=IFCSIMPLEPROPERTYTEMPLATE('0SVyOfB0rC2xNfdRYf3XvY',$,'SuppressZeroInches','Suppress 0 inch values in dimension annotation text (for example: 12'' - 0" -> 12'')',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
 #27=IFCSIMPLEPROPERTYTEMPLATE('2bUmj458PBqPAtUoI3MXsb',$,'TextPrefix','Text to add before annotation measurement value',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
@@ -38,5 +38,14 @@ DATA;
 #31=IFCPROPERTYENUMERATION('CustomUnit',(IFCTEXT('Feet and Inches - Fractional'),IFCTEXT('Feet - Decimal'),IFCTEXT('Inches - Fractional'),IFCTEXT('Inches - Decimal'),IFCTEXT('Meters'),IFCTEXT('Decimeters'),IFCTEXT('Centimeters'),IFCTEXT('Millimeters')),$);
 #32=IFCSIMPLEPROPERTYTEMPLATE('0gjJzDYBX8P85qn1xcAOOo',$,'Reverse_List','',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
 #33=IFCSIMPLEPROPERTYTEMPLATE('22TrcxF8jFNB4buSmzjGEF',$,'List_Separator','',.P_SINGLEVALUE.,'IfcText',$,$,$,$,$,.READWRITE.);
+#34=IFCSIMPLEPROPERTYTEMPLATE('1Kx4Pm9nR8vBwZqTs2uYeL',$,'Separator','Characters placed between multiple dimension values when CustomUnit has more than one unit selected (default: '' / '')',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
+#35=IFCSIMPLEPROPERTYTEMPLATE('3Nf6Qs1mT0pWxBuCvDyEzA',$,'SuppressZeroFeet','Suppress 0 feet in dimension annotation text (for example: 0'' - 3 1/2" -> 3 1/2")',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#36=IFCSIMPLEPROPERTYTEMPLATE('2Rg7Hn5jK4mLpNqOsVwXtY',$,'IsOrdinate','Show accumulated distance from the first vertex instead of individual segment lengths',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#37=IFCSIMPLEPROPERTYTEMPLATE('1XpRnKoT2sGuW7vYcZaMqb',$,'Anchors','JSON array of parametric anchor descriptors — one per polyline vertex. Each entry: {"guid": str|null, "type": "FACE"|"CIRCLE_CENTER"|"WORLD", "addr": {...}, "hint": [x,y,z]|null, "pt": [x,y,z]}',.P_SINGLEVALUE.,'IfcText',$,$,$,$,$,.READWRITE.);
+#38=IFCSIMPLEPROPERTYTEMPLATE('2YqSmLoU3tHvX8wZdaNrjc',$,'MeasureAxis','Axis along which distances are projected: X | Y | Z | TRUE | PERPENDICULAR',.P_SINGLEVALUE.,'IfcLabel',$,$,$,$,$,.READWRITE.);
+#39=IFCSIMPLEPROPERTYTEMPLATE('3Ny31Go6T5Z9fh8j4yQC0p',$,'ForcePerpendicularToFace','When enabled the polyline is constrained to follow the face normal of the first anchor vertex so the dimension measures straight-line distance perpendicular to that face',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#40=IFCSIMPLEPROPERTYTEMPLATE('1LoNpKqR3sTuVwXyZaBcDe',$,'LinePosition','Absolute world-space coordinate (metres) of the dimension line along the horizontal offset axis (perpendicular to the dimension direction). When set, the dimension line is held at this fixed global position even if the measured geometry moves. When absent the line sits at the anchor points.',.P_SINGLEVALUE.,'IfcLengthMeasure',$,$,$,$,$,.READWRITE.);
+#41=IFCSIMPLEPROPERTYTEMPLATE('0FauxIsAnnotFaux0001aB',$,'IsManualDrawingReference','Marks this annotation as a manually placed drawing reference, exempt from automatic drawing regeneration.',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
+#42=IFCSIMPLEPROPERTYTEMPLATE('0FauxIsDocRefFaux001aB',$,'IsDocumentReference','Marks this annotation as pointing to an external document reference (not a Bonsai drawing camera).',.P_SINGLEVALUE.,'IfcBoolean',$,$,$,$,$,.READWRITE.);
 ENDSEC;
 END-ISO-10303-21;

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

@@ -30,6 +30,7 @@ classes = (
     operator.ActivateModel,
     operator.AddAnnotation,
     operator.AddAnnotationType,
+    operator.AssignManualDrawingReference,
     operator.AddDrawing,
     operator.AddDrawingStyle,
     operator.AddDrawingToSheet,
@@ -107,6 +108,11 @@ classes = (
     operator.ToggleTargetView,
     operator.OpenDocumentationWebUi,
     operator.FilterSelectedObjectsIfIntersectedByCamera,
+    operator.DrawParametricDimension,
+    operator.SetDimensionAnchor,
+    operator.RegenerateDimensions,
+    operator.ClickNearestDimensionAnchor,
+    operator.DebugDimensionClicks,
     prop.Variable,
     prop.Drawing,
     prop.Document,
@@ -148,11 +154,17 @@ classes = (
     gizmos.UglyDotGizmo,
     gizmos.ExtrusionGuidesGizmo,
     gizmos.ExtrusionWidget,
+    gizmos.GizmoAnchorHandle,
+    gizmos.DimensionAnchorWidget,
+    gizmos.DimensionLinePositionWidget,
     workspace.LaunchAnnotationTypeManager,
     workspace.Hotkey,
 )
 
 
+_keymaps = []
+
+
 def menu_func(self, context):
     active_obj = context.active_object
     if active_obj:
@@ -172,9 +184,17 @@ def register():
     bpy.types.TextCurve.BIMTextProperties = bpy.props.PointerProperty(type=prop.BIMTextProperties)
     bpy.app.handlers.load_post.append(handler.load_post)
     bpy.app.handlers.depsgraph_update_pre.append(handler.depsgraph_update_pre_handler)
+    bpy.app.handlers.depsgraph_update_post.append(handler.depsgraph_update_post_handler)
     bpy.types.VIEW3D_MT_image_add.append(ui.add_object_button)
     bpy.types.VIEW3D_MT_object_context_menu.append(menu_func)
 
+    wm = bpy.context.window_manager
+    kc = wm.keyconfigs.addon
+    if kc:
+        km = kc.keymaps.new(name="3D View", space_type="VIEW_3D")
+        kmi = km.keymap_items.new("bim.click_nearest_dimension_anchor", "LEFTMOUSE", "PRESS")
+        _keymaps.append((km, kmi))
+
 
 def unregister():
     if not bpy.app.background:
@@ -187,5 +207,10 @@ def unregister():
     del bpy.types.TextCurve.BIMTextProperties
     bpy.app.handlers.load_post.remove(handler.load_post)
     bpy.app.handlers.depsgraph_update_pre.remove(handler.depsgraph_update_pre_handler)
+    bpy.app.handlers.depsgraph_update_post.remove(handler.depsgraph_update_post_handler)
+
+    for km, kmi in _keymaps:
+        km.keymap_items.remove(kmi)
+    _keymaps.clear()
     bpy.types.VIEW3D_MT_image_add.remove(ui.add_object_button)
     bpy.types.VIEW3D_MT_object_context_menu.remove(menu_func)

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

@@ -55,6 +55,14 @@ class ProductAssignmentsData:
         element = tool.Ifc.get_entity(bpy.context.active_object)
         if not element or not element.is_a("IfcAnnotation"):
             return
+        # Document-reference annotations link to an IfcDocumentInformation, not a product.
+        if tool.Drawing.is_document_reference(element):
+            for rel in element.HasAssociations:
+                if rel.is_a("IfcRelAssociatesDocument"):
+                    doc = rel.RelatingDocument
+                    if doc.is_a("IfcDocumentInformation"):
+                        return doc.Name or "Unnamed"
+            return None
         for rel in element.HasAssignments:
             if rel.is_a("IfcRelAssignsToProduct"):
                 name = rel.RelatingProduct.Name or "Unnamed"
@@ -799,19 +807,24 @@ class DecoratorData:
         pset_data = ifcopenshell.util.element.get_pset(element, "BBIM_Dimension") or {}
         show_description_only = pset_data.get("ShowDescriptionOnly", False)
         suppress_zero_inches = pset_data.get("SuppressZeroInches", False)
+        suppress_zero_feet = pset_data.get("SuppressZeroFeet", False)
+        is_ordinate = pset_data.get("IsOrdinate", False)
         text_prefix = pset_data.get("TextPrefix", None) or ""
         text_suffix = pset_data.get("TextSuffix", None) or ""
-        custom_unit_list = pset_data.get("CustomUnit", None) or ""
-        custom_unit = custom_unit_list[0] if custom_unit_list else ""
+        custom_units = list(pset_data.get("CustomUnit", None) or [])
+        separator = pset_data.get("Separator", None) or " / "
 
         return {
             "dimension_style": dimension_style,
             "show_description_only": show_description_only,
             "suppress_zero_inches": suppress_zero_inches,
+            "suppress_zero_feet": suppress_zero_feet,
+            "is_ordinate": is_ordinate,
             "text_prefix": text_prefix,
             "text_suffix": text_suffix,
             "fill_bg": fill_bg,
-            "custom_unit": custom_unit,
+            "custom_units": custom_units,
+            "separator": separator,
         }
 
     @classmethod

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

@@ -490,7 +490,7 @@ class BaseDecorator:
         self.draw_label(context, text=text, line_no=line_number_start, multiline=True, **draw_label_kwargs)
 
     @cache
-    def format_value(self, context, value, suppress_zero_inches=False, custom_unit=None, in_unit_length=False):
+    def format_value(self, context, value, suppress_zero_inches=False, suppress_zero_feet=False, custom_unit=None, in_unit_length=False):
         drawing_pset_data = DrawingsData.data["active_drawing_pset_data"]
         precision = drawing_pset_data.get("MetricPrecision", None)
         if not precision:
@@ -502,6 +502,7 @@ class BaseDecorator:
             precision=precision,
             decimal_places=decimal_places,
             suppress_zero_inches=suppress_zero_inches,
+            suppress_zero_feet=suppress_zero_feet,
             custom_unit=custom_unit,
             in_unit_length=in_unit_length,
         )
@@ -718,11 +719,13 @@ class DimensionDecorator(BaseDecorator):
         if not dimension_data:
             return
         show_description_only = dimension_data["show_description_only"]
+        is_ordinate = dimension_data["is_ordinate"]
         text_prefix = dimension_data["text_prefix"]
         text_suffix = dimension_data["text_suffix"]
         viewportDrawingScale = self.get_viewport_drawing_scale(context)
         text_offset_value = viewportDrawingScale * 3
 
+        ordinate_total = 0.0
         for i0, i1 in indices:
             v0 = Vector(vertices[i0])
             v1 = Vector(vertices[i1])
@@ -741,16 +744,25 @@ class DimensionDecorator(BaseDecorator):
                 "multiline": True,
                 "text_dir": text_dir,
             }
-            base_pos = p0 + text_dir * 0.5
+            base_pos = p1 if is_ordinate else p0 + text_dir * 0.5
 
             if not show_description_only:
-                length = (v1 - v0).length
-                text = self.format_value(
-                    context,
-                    length,
-                    suppress_zero_inches=dimension_data["suppress_zero_inches"],
-                    custom_unit=dimension_data["custom_unit"],
-                )
+                segment_length = (v1 - v0).length
+                if is_ordinate:
+                    ordinate_total += segment_length
+                length = ordinate_total if is_ordinate else segment_length
+                units_to_format = dimension_data["custom_units"] if dimension_data["custom_units"] else [None]
+                parts = [
+                    self.format_value(
+                        context,
+                        length,
+                        suppress_zero_inches=dimension_data["suppress_zero_inches"],
+                        suppress_zero_feet=dimension_data["suppress_zero_feet"],
+                        custom_unit=unit,
+                    )
+                    for unit in units_to_format
+                ]
+                text = dimension_data["separator"].join(str(p) for p in parts)
                 if isinstance(self, DiameterDecorator):
                     text = "D" + text
                 text = text_prefix + text + text_suffix
@@ -761,15 +773,18 @@ class DimensionDecorator(BaseDecorator):
 
             self.draw_label(
                 text=text,
-                pos=base_pos + text_offset,
-                box_alignment="bottom-middle",
+                pos=base_pos + text_offset + (Vector((0, text_offset_value)) if is_ordinate else Vector((0, 0))),
+                box_alignment="bottom-right" if is_ordinate else "bottom-middle",
                 multiline_to_bottom=False,
                 **common_label_attrs,
             )
 
             if not show_description_only and description:
                 self.draw_label(
-                    text=description, pos=base_pos - text_offset, box_alignment="top-middle", **common_label_attrs
+                    text=description,
+                    pos=base_pos - text_offset + (Vector((0, text_offset_value)) if is_ordinate else Vector((0, 0))),
+                    box_alignment="top-right" if is_ordinate else "top-middle",
+                    **common_label_attrs,
                 )
 
 
@@ -965,7 +980,9 @@ class RadiusDecorator(BaseDecorator):
 
         def get_text():
             length = (spline_points[-1] - spline_points[-2]).length
-            return "R" + self.format_value(context, length, custom_unit=dimension_data["custom_unit"])
+            units_to_format = dimension_data["custom_units"] if dimension_data["custom_units"] else [None]
+            parts = [self.format_value(context, length, suppress_zero_feet=dimension_data["suppress_zero_feet"], custom_unit=unit) for unit in units_to_format]
+            return "R" + dimension_data["separator"].join(str(p) for p in parts)
 
         self.draw_dimension_text(
             context, get_text, description, dimension_data, pos=pos, text_dir=Vector((1, 0)), box_alignment="center"
@@ -1497,6 +1514,20 @@ class ElevationDecorator(BaseDecorator):
             "output_edges": output_edges,
         }
 
+        # Determine the arrow direction in camera-image-plane (XY) space.
+        # The elevation tag's local -Z is intentionally parallel to the drawing
+        # camera's view direction, so projecting it always gives a near-zero XY
+        # delta.  Fall through to local +X (which is perpendicular to the view
+        # and rotates visibly when the user spins the tag).
+        view_mat = context.region_data.view_matrix
+        edge_dir_2d = Vector((1.0, 0.0))  # final fallback
+        for local_axis in (Vector((0, 0, -1)), Vector((1, 0, 0)), Vector((0, 1, 0))):
+            world_axis = obj.matrix_world.to_3x3() @ local_axis
+            cam_xy = (view_mat.to_3x3() @ world_axis).xy
+            if cam_xy.length > 1e-6:
+                edge_dir_2d = cam_xy.normalized()
+                break
+
         # process edges
         for edge in edges_original:
             v0, v1 = winspace_verts[edge[0]], winspace_verts[edge[1]]
@@ -1505,7 +1536,7 @@ class ElevationDecorator(BaseDecorator):
             circle_head = get_circle_head(circle_size)
             start_i = add_verts_sequence(add_offsets(v0, circle_head), start_i, **out_kwargs, closed=True)
 
-            edge_dir = (v1 - v0).normalized()
+            edge_dir = edge_dir_2d.to_3d()
             side = (edge_dir.yx * Vector((1, -1))).to_3d()
             triangle_head = get_triangle_head(side, edge_dir, triangle_length, triangle_width)
             start_i = add_verts_sequence(add_offsets(v0, triangle_head), start_i, **out_kwargs, closed=True)
@@ -2090,4 +2121,8 @@ class DecorationsHandler:
 
         object_decorators = DecoratorData.data.get("object_decorators", [])
         for obj, decorator in object_decorators:
-            decorator.decorate(context, obj)
+            try:
+                decorator.decorate(context, obj)
+            except ReferenceError:
+                DecoratorData.is_loaded = False
+                break

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

@@ -1789,6 +1789,19 @@ DISC = (
     (1.0, 0.0, 0),
 )
 
+# Anchor index currently being edited by SetDimensionAnchor (-1 = none).
+_active_anchor_idx: int = -1
+# The annotation curve object being edited (kept so the gizmo group stays
+# visible even when SetDimensionAnchor temporarily changes the active object).
+_editing_annotation_obj = None
+
+
+def set_active_anchor(idx: int, annotation_obj=None) -> None:
+    global _active_anchor_idx, _editing_annotation_obj
+    _active_anchor_idx = idx
+    _editing_annotation_obj = annotation_obj if idx >= 0 else None
+
+
 X3DISC = (
     (0.0, 0.0, 0.0),
     (1.0, 0.0, 0),
@@ -2120,6 +2133,340 @@ class ExtrusionWidget(types.GizmoGroup):
         self.handle.target_set_prop("offset", prop, "value")
         self.guides.target_set_prop("depth", prop, "value")
 
+
+class GizmoAnchorHandle(bpy.types.Gizmo):
+    """Visual-only dot at a parametric dimension vertex.
+
+    No draw_select/invoke — any draw_select entry puts the gizmo in Blender's
+    select buffer, which causes the gizmo system to consume the click even
+    without an explicit invoke.  All click handling is done by the
+    bim.click_nearest_dimension_anchor keymap operator.
+    """
+
+    bl_idname = "BIM_GT_anchor_handle"
+
+    __slots__ = ("anchor_index", "custom_shape")
+
+    def setup(self):
+        self.anchor_index = 0
+        self.custom_shape = self.new_custom_shape(type="TRIS", verts=X3DISC)
+
+    def draw(self, context):
+        self.draw_custom_shape(self.custom_shape)
+
+
+
+class DimensionAnchorWidget(types.GizmoGroup):
+    """Anchor handle gizmos at each vertex of the active parametric dimension.
+
+    Green dots indicate vertices that are anchored to an IFC element face;
+    orange dots are free world-point anchors.  Clicking any dot fires
+    ``bim.set_dimension_anchor`` pre-targeted at that vertex index.
+    """
+
+    bl_idname = "BIM_GGT_dimension_anchors"
+    bl_label = "Dimension Anchor Handles"
+    bl_space_type = "VIEW_3D"
+    bl_region_type = "WINDOW"
+    bl_options = {"3D", "PERSISTENT", "SHOW_MODAL_ALL"}
+
+    _DIM_TYPES = frozenset(("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"))
+    _MAX_ANCHORS = 16
+
+    @classmethod
+    def poll(cls, context: bpy.types.Context) -> bool:
+        if not tool.Ifc.get():
+            return False
+        # Stay visible while SetDimensionAnchor is running (active obj may temporarily
+        # be an IFC element in the face-picking phase rather than the annotation).
+        if _active_anchor_idx >= 0 and _editing_annotation_obj is not None:
+            active = context.active_object
+            if active is _editing_annotation_obj:
+                return True  # annotation still active
+            if active is not None and tool.Ifc.get_entity(active) is not None:
+                return True  # face-picking phase: active obj is a target element
+            # Active object is None or a non-IFC object — the modal ended without
+            # calling set_active_anchor(-1).  Reset stale state and fall through.
+            set_active_anchor(-1)
+        obj = context.active_object
+        if not obj or obj.type != "CURVE":
+            return False
+        if not obj.select_get():
+            return False
+        element = tool.Ifc.get_entity(obj)
+        if not element or not element.is_a("IfcAnnotation"):
+            return False
+        import ifcopenshell.util.element as _ue
+        if _ue.get_predefined_type(element) not in cls._DIM_TYPES:
+            return False
+        pset = _ue.get_pset(element, "BBIM_Dimension")
+        return bool(pset and pset.get("Anchors"))
+
+    def setup(self, context: bpy.types.Context) -> None:
+        self._handles: list = []
+        for _ in range(self._MAX_ANCHORS):
+            gz = self.gizmos.new("BIM_GT_anchor_handle")
+            gz.scale_basis = 0.2
+            gz.use_draw_modal = True
+            gz.hide = True
+            self._handles.append(gz)
+
+    def refresh(self, context: bpy.types.Context) -> None:
+        import json
+        import ifcopenshell.util.element as _ue
+
+        obj = _editing_annotation_obj if _active_anchor_idx >= 0 and _editing_annotation_obj else context.active_object
+        if not obj or not obj.data or not getattr(obj.data, "splines", None):
+            for gz in self._handles:
+                gz.hide = True
+            return
+
+        element = tool.Ifc.get_entity(obj)
+        if not element:
+            for gz in self._handles:
+                gz.hide = True
+            return
+
+        pset = _ue.get_pset(element, "BBIM_Dimension")
+        if not pset or not pset.get("Anchors"):
+            for gz in self._handles:
+                gz.hide = True
+            return
+
+        try:
+            anchors = json.loads(pset["Anchors"])
+        except Exception:
+            for gz in self._handles:
+                gz.hide = True
+            return
+
+        spline = obj.data.splines[0]
+        n = min(len(spline.points), len(anchors), self._MAX_ANCHORS)
+
+        for i in range(n):
+            gz = self._handles[i]
+            raw_co = spline.points[i].co
+            world_co = obj.matrix_world @ raw_co.to_3d()
+            gz.matrix_basis = Matrix.Translation(world_co)
+            gz.anchor_index = i
+            if i == _active_anchor_idx and obj is _editing_annotation_obj:
+                gz.color = (0.2, 0.7, 1.0)
+                gz.color_highlight = (0.4, 0.85, 1.0)
+            elif anchors[i].get("guid"):
+                gz.color = (0.2, 0.85, 0.2)
+                gz.color_highlight = (0.4, 1.0, 0.4)
+            else:
+                gz.color = (0.9, 0.6, 0.1)
+                gz.color_highlight = (1.0, 0.85, 0.2)
+            gz.alpha = 0.85
+            gz.alpha_highlight = 1.0
+            gz.hide = False
+
+        for i in range(n, self._MAX_ANCHORS):
+            self._handles[i].hide = True
+
+    def draw_prepare(self, context: bpy.types.Context) -> None:
+        self.refresh(context)
+
+
+class DimensionLinePositionWidget(types.GizmoGroup):
+    """Drag handle for the LinePosition of a parametric dimension annotation.
+
+    Shows two opposing cones at the midpoint of the dimension curve, oriented
+    along the horizontal offset axis (cross(world_Z, dim_direction)).  Dragging
+    either cone updates BBIM_Dimension.LinePosition and regenerates the curve in
+    real time.  The forward cone points in +offset_dir; the reverse cone in
+    -offset_dir — both respond to mouse movement along the shared axis so the
+    user can drag in either direction from either handle.
+    """
+
+    bl_idname = "BIM_GGT_dimension_line_position"
+    bl_label = "Dimension Line Position"
+    bl_space_type = "VIEW_3D"
+    bl_region_type = "WINDOW"
+    bl_options = {"3D", "PERSISTENT", "SHOW_MODAL_ALL"}
+
+    _DIM_TYPES = frozenset(("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"))
+
+    @classmethod
+    def poll(cls, context: bpy.types.Context) -> bool:
+        if not tool.Ifc.get():
+            return False
+        obj = context.active_object
+        if not obj or obj.type != "CURVE":
+            return False
+        element = tool.Ifc.get_entity(obj)
+        if not element or not element.is_a("IfcAnnotation"):
+            return False
+        import ifcopenshell.util.element as _ue
+        if _ue.get_predefined_type(element) not in cls._DIM_TYPES:
+            return False
+        pset = _ue.get_pset(element, "BBIM_Dimension")
+        return bool(pset and pset.get("Anchors") and pset.get("ForcePerpendicularToFace"))
+
+    # ------------------------------------------------------------------
+    # Helpers
+
+    @staticmethod
+    def _offset_dir(obj: bpy.types.Object) -> "Vector | None":
+        """World-space unit direction perpendicular to the dimension line and world_Z."""
+        if not obj.data or not hasattr(obj.data, "splines") or not obj.data.splines:
+            return None
+        spline = obj.data.splines[0]
+        if len(spline.points) < 2:
+            return None
+        a = obj.matrix_world @ spline.points[0].co.to_3d()
+        b = obj.matrix_world @ spline.points[-1].co.to_3d()
+        dim = b - a
+        if dim.length < 1e-10:
+            return None
+        dim.normalize()
+        world_z = Vector((0.0, 0.0, 1.0))
+        od = world_z.cross(dim)
+        if od.length < 1e-6:
+            od = Vector((1.0, 0.0, 0.0)).cross(dim)
+        if od.length < 1e-6:
+            return None
+        return od.normalized()
+
+    @staticmethod
+    def _midpoint(obj: bpy.types.Object) -> "Vector":
+        spline = obj.data.splines[0]
+        pts = [obj.matrix_world @ p.co.to_3d() for p in spline.points]
+        return sum(pts, Vector()) / len(pts)
+
+    @staticmethod
+    def _basis(origin: "Vector", x_axis: "Vector") -> "Matrix":
+        """4×4 matrix with translation=origin, local-X=x_axis."""
+        ref = Vector((0.0, 0.0, 1.0)) if abs(x_axis.dot(Vector((0.0, 0.0, 1.0)))) < 0.9 else Vector((1.0, 0.0, 0.0))
+        y_ax = x_axis.cross(ref).normalized()
+        z_ax = x_axis.cross(y_ax)
+        return Matrix([
+            [x_axis.x, y_ax.x, z_ax.x, origin.x],
+            [x_axis.y, y_ax.y, z_ax.y, origin.y],
+            [x_axis.z, y_ax.z, z_ax.z, origin.z],
+            [0.0,      0.0,    0.0,    1.0],
+        ])
+
+    # ------------------------------------------------------------------
+    # Value callbacks
+
+    def _get_pos(self) -> float:
+        obj = bpy.context.active_object
+        if not obj:
+            return 0.0
+        element = tool.Ifc.get_entity(obj)
+        if not element:
+            return 0.0
+        import ifcopenshell.util.element as _ue
+        pset = _ue.get_pset(element, "BBIM_Dimension")
+        if not pset:
+            return 0.0
+        stored = pset.get("LinePosition")
+        if stored is not None:
+            return float(stored)
+        # Natural position: projection of midpoint onto offset axis
+        od = self._offset_dir(obj)
+        if od is None:
+            return 0.0
+        return self._midpoint(obj).dot(od)
+
+    def _set_pos(self, value: float) -> None:
+        bpy.ops.ed.undo_push(message="Set Line Position")
+        import json
+        import numpy as np
+        import ifcopenshell.util.element as _ue
+        import ifcopenshell.api.pset as _pset_api
+        import ifcopenshell.api.drawing as drawing_api
+        from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+        obj = bpy.context.active_object
+        if not obj:
+            return
+        file = tool.Ifc.get()
+        if not file:
+            return
+        element = tool.Ifc.get_entity(obj)
+        if not element:
+            return
+        pset_data = _ue.get_pset(element, "BBIM_Dimension")
+        if not pset_data:
+            return
+
+        pset_entity = file.by_id(pset_data["id"])
+        _pset_api.edit_pset(file, pset=pset_entity, properties={"LinePosition": value})
+
+        anchors = json.loads(pset_data.get("Anchors") or "[]")
+        placement_override: dict = {}
+        for a in anchors:
+            guid = a.get("guid")
+            if not guid:
+                continue
+            try:
+                elem = file.by_guid(guid)
+                elem_obj = tool.Ifc.get_object(elem)
+                if elem_obj:
+                    placement_override[elem.id()] = np.array(elem_obj.matrix_world)
+            except Exception:
+                pass
+
+        resolved_pts = drawing_api.regenerate_dimension(file, element, placement_override=placement_override)
+        if resolved_pts:
+            _update_blender_curve(element, resolved_pts)
+        tool.Blender.update_viewport()
+
+    # ------------------------------------------------------------------
+    # GizmoGroup interface
+
+    def _make_cone(self, color: tuple, highlight: tuple) -> "bpy.types.Gizmo":
+        gz = self.gizmos.new("BIM_GT_gizmo_cone")
+        gz.color = color
+        gz.alpha = 0.8
+        gz.color_highlight = highlight
+        gz.alpha_highlight = 1.0
+        gz.scale_basis = 0.15
+        gz.use_draw_modal = True
+        gz.prop_name = "Line Position"
+        gz.move_get_cb = self._get_pos
+        gz.move_set_cb = self._set_pos
+        gz.gizmo_group = self
+        gz.delta_scale = 1.0
+        return gz
+
+    def setup(self, context: bpy.types.Context) -> None:
+        color = (0.9, 0.6, 0.1)
+        highlight = (1.0, 0.9, 0.2)
+        self.gz_fwd = self._make_cone(color, highlight)
+        self.gz_rev = self._make_cone(color, highlight)
+
+    def refresh(self, context: bpy.types.Context) -> None:
+        obj = context.active_object
+        if not obj:
+            self.gz_fwd.hide = self.gz_rev.hide = True
+            return
+
+        od = self._offset_dir(obj)
+        if od is None:
+            self.gz_fwd.hide = self.gz_rev.hide = True
+            return
+
+        mid = self._midpoint(obj)
+        # Lift each cone off the dimension line so the arrow base doesn't
+        # overlap anchor dots.  0.3 m gives clear separation at typical zoom.
+        _GAP = 0.15
+        fwd_origin = mid + _GAP * od
+        rev_origin = mid - _GAP * od
+
+        self.gz_fwd.matrix_basis = self._basis(fwd_origin, od)
+        self.gz_fwd.axis = od.copy()
+        self.gz_fwd.hide = False
+
+        # Reverse cone: visually points in -od; same drag axis so both cones
+        # respond identically — drag toward either tip to move the line.
+        self.gz_rev.matrix_basis = self._basis(rev_origin, -od)
+        self.gz_rev.axis = od.copy()
+        self.gz_rev.hide = False
+
     @staticmethod
     def get_scale_value(system: str, length_unit: str) -> float:
         scale_value = 1

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

@@ -16,15 +16,141 @@
 # You should have received a copy of the GNU General Public License
 # along with Bonsai.  If not, see <http://www.gnu.org/licenses/>.
 
+import json
+
 import bpy
+import numpy as np
 from bpy.app.handlers import persistent
 
 import bonsai.bim.module.drawing.decoration as decoration
 import bonsai.tool as tool
 
+# ---------------------------------------------------------------------------
+# Parametric dimension auto-regeneration state
+# ---------------------------------------------------------------------------
+
+# Maps element GUID → list of annotation STEP IDs that reference it.
+_dim_guid_index: dict = {}
+# Persistent tessellation cache for the depsgraph handler (element id → shape).
+_dim_shape_cache: dict = {}
+# Set True whenever BBIM_Dimension anchors change or a new file loads.
+_dim_index_dirty: bool = True
+# Re-entry guard so curve updates don't trigger a second handler call.
+_dim_handler_running: bool = False
+
+
+def invalidate_dim_index() -> None:
+    """Mark the GUID index as stale so it is rebuilt on the next handler call."""
+    global _dim_index_dirty, _dim_shape_cache
+    _dim_index_dirty = True
+    _dim_shape_cache.clear()
+
+
+def _rebuild_dim_guid_index(file) -> None:
+    global _dim_guid_index, _dim_index_dirty
+    import ifcopenshell.util.element
+
+    _dim_guid_index = {}
+    for annotation in file.by_type("IfcAnnotation"):
+        pset_data = ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension")
+        if not pset_data or not pset_data.get("Anchors"):
+            continue
+        try:
+            anchors = json.loads(pset_data["Anchors"])
+        except Exception:
+            continue
+        ann_id = annotation.id()
+        for anchor in anchors:
+            guid = anchor.get("guid")
+            if not guid:
+                continue
+            ids = _dim_guid_index.setdefault(guid, [])
+            if ann_id not in ids:
+                ids.append(ann_id)
+    _dim_index_dirty = False
+
+
+def regenerate_dims_for_layer(file, layer) -> None:
+    """Regenerate all parametric dimensions anchored to elements that use *layer*."""
+    global _dim_shape_cache, _dim_index_dirty, _dim_guid_index
+
+    if _dim_index_dirty:
+        _rebuild_dim_guid_index(file)
+
+    affected_guids: set = set()
+    for layer_set in file.get_inverse(layer):
+        if not layer_set.is_a("IfcMaterialLayerSet"):
+            continue
+        for inv in file.get_inverse(layer_set):
+            if inv.is_a("IfcRelAssociatesMaterial"):
+                rels = [inv]
+            elif inv.is_a("IfcMaterialLayerSetUsage"):
+                rels = [r for r in file.get_inverse(inv) if r.is_a("IfcRelAssociatesMaterial")]
+            else:
+                continue
+            for rel in rels:
+                for element in rel.RelatedObjects:
+                    if hasattr(element, "GlobalId"):
+                        affected_guids.add(element.GlobalId)
+                        _dim_shape_cache.pop(element.id(), None)
+
+    if not affected_guids:
+        return
+
+    annotation_ids: set = set()
+    for guid in affected_guids:
+        for ann_id in _dim_guid_index.get(guid, []):
+            annotation_ids.add(ann_id)
+
+    if not annotation_ids:
+        return
+
+    import ifcopenshell.util.element
+    import ifcopenshell.api.drawing as drawing_api
+    import ifcopenshell.geom
+    from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+    geom_settings = ifcopenshell.geom.settings()
+    geom_settings.set("APPLY_DEFAULT_MATERIALS", False)
+
+    for ann_id in annotation_ids:
+        try:
+            annotation = file.by_id(ann_id)
+        except Exception:
+            continue
+        pset = ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension")
+        if not pset:
+            continue
+        placement_override: dict = {}
+        try:
+            anchors_raw = json.loads(pset.get("Anchors") or "[]")
+            for anchor in anchors_raw:
+                guid = anchor.get("guid")
+                if not guid:
+                    continue
+                try:
+                    elem = file.by_guid(guid)
+                    elem_obj = tool.Ifc.get_object(elem)
+                    if elem_obj:
+                        placement_override[elem.id()] = np.array(elem_obj.matrix_world)
+                except Exception:
+                    pass
+        except Exception:
+            pass
+        resolved_pts = drawing_api.regenerate_dimension(
+            file,
+            annotation,
+            settings=geom_settings,
+            shape_cache=_dim_shape_cache,
+            placement_override=placement_override,
+        )
+        if resolved_pts:
+            _update_blender_curve(annotation, resolved_pts)
+
 
 @persistent
 def load_post(*args):
+    invalidate_dim_index()
     props = tool.Drawing.get_document_props()
     if props.should_draw_decorations:
         decoration.DecorationsHandler.install(bpy.context)
@@ -58,3 +184,177 @@ def set_active_camera_resolution(scene: bpy.types.Scene) -> None:
         raster_x, raster_y = props.update_camera_resolution()
         scene_render.resolution_x = raster_x
         scene_render.resolution_y = raster_y
+
+
+def _sync_dimension_anchors_to_curve(file, annotation, obj) -> bool:
+    """Sync BBIM_Dimension.Anchors length to match the curve's spline point count.
+
+    Called when the user adds or removes vertices from a dimension annotation in
+    Edit Mode.  New vertices get a free WORLD-type anchor at their current world
+    position; removed tail vertices simply lose their anchor entries.
+
+    Returns True if the pset was changed.
+    """
+    import ifcopenshell.util.element
+    import ifcopenshell.api.pset
+
+    if not obj.data or not getattr(obj.data, "splines", None) or not obj.data.splines:
+        return False
+
+    pset_data = ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension")
+    if not pset_data or not pset_data.get("Anchors"):
+        return False
+
+    try:
+        anchors: list = json.loads(pset_data["Anchors"])
+    except Exception:
+        return False
+
+    spline = obj.data.splines[0]
+    spline_world = [obj.matrix_world @ p.co.to_3d() for p in spline.points]
+    n_pts = len(spline_world)
+    n_anchors = len(anchors)
+
+    if n_pts == n_anchors:
+        return False
+
+    # Match each spline point to the nearest unused anchor by proximity.
+    # This handles insertions (subdivide) and deletions correctly regardless
+    # of where in the polyline the edit happened.
+    _MATCH_THRESH_SQ = 1e-4  # 1 cm² — distinguishes existing pts from new midpoints
+    used: set = set()
+    new_anchors: list = []
+
+    for pt in spline_world:
+        best_idx, best_sq = None, float("inf")
+        for i, anc in enumerate(anchors):
+            if i in used:
+                continue
+            stored = anc.get("pt")
+            if not stored:
+                continue
+            dx, dy, dz = stored[0] - pt.x, stored[1] - pt.y, stored[2] - pt.z
+            sq = dx * dx + dy * dy + dz * dz
+            if sq < best_sq:
+                best_sq, best_idx = sq, i
+        if best_idx is not None and best_sq < _MATCH_THRESH_SQ:
+            new_anchors.append(anchors[best_idx])
+            used.add(best_idx)
+        else:
+            new_anchors.append({
+                "guid": None,
+                "type": "WORLD",
+                "addr": {},
+                "hint": None,
+                "pt": [pt.x, pt.y, pt.z],
+            })
+
+
+    pset_entity = file.by_id(pset_data["id"])
+    ifcopenshell.api.pset.edit_pset(file, pset=pset_entity, properties={"Anchors": json.dumps(new_anchors)})
+    invalidate_dim_index()
+    return True
+
+
+@persistent
+def depsgraph_update_post_handler(scene, depsgraph):
+    """Auto-regenerate parametric dimensions when referenced elements are moved."""
+    global _dim_handler_running, _dim_index_dirty, _dim_guid_index, _dim_shape_cache
+
+    if _dim_handler_running:
+        return
+
+    file = tool.Ifc.get()
+    if not file:
+        return
+
+    if _dim_index_dirty:
+        _rebuild_dim_guid_index(file)
+
+    import ifcopenshell.util.element
+
+    moved_guids: set = set()
+    edited_annotation_ids: set = set()
+
+    for update in depsgraph.updates:
+        obj = update.id
+        if not isinstance(obj, bpy.types.Object):
+            continue
+        if not (update.is_updated_transform or update.is_updated_geometry):
+            continue
+        element = tool.Ifc.get_entity(obj)
+        if element is None or not hasattr(element, "GlobalId"):
+            continue
+
+
+        if update.is_updated_geometry and obj.type == "CURVE" and element.is_a("IfcAnnotation"):
+            import ifcopenshell.util.element as _ue
+            ptype = _ue.get_predefined_type(element)
+            if ptype in ("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"):
+                changed = _sync_dimension_anchors_to_curve(file, element, obj)
+                if changed:
+                    edited_annotation_ids.add(element.id())
+                continue
+
+        moved_guids.add(element.GlobalId)
+        if update.is_updated_geometry:
+            _dim_shape_cache.pop(element.id(), None)
+
+    annotation_ids: set = set(edited_annotation_ids)
+    for guid in moved_guids:
+        for ann_id in _dim_guid_index.get(guid, []):
+            annotation_ids.add(ann_id)
+
+    if not annotation_ids:
+        return
+
+    import ifcopenshell.api.drawing as drawing_api
+    import ifcopenshell.geom
+    from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+    geom_settings = ifcopenshell.geom.settings()
+    geom_settings.set("APPLY_DEFAULT_MATERIALS", False)
+
+    _dim_handler_running = True
+    try:
+        for ann_id in annotation_ids:
+            try:
+                annotation = file.by_id(ann_id)
+            except Exception:
+                continue
+
+            pset = ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension")
+            if not pset:
+                continue
+
+            placement_override: dict = {}
+            try:
+                anchors_raw = json.loads(pset.get("Anchors") or "[]")
+                for anchor in anchors_raw:
+                    guid = anchor.get("guid")
+                    if not guid:
+                        continue
+                    try:
+                        elem = file.by_guid(guid)
+                        elem_id = elem.id()
+                        if elem_id in placement_override:
+                            continue
+                        elem_obj = tool.Ifc.get_object(elem)
+                        if elem_obj:
+                            placement_override[elem_id] = np.array(elem_obj.matrix_world)
+                    except Exception:
+                        pass
+            except Exception:
+                pass
+
+            resolved_pts = drawing_api.regenerate_dimension(
+                file,
+                annotation,
+                settings=geom_settings,
+                shape_cache=_dim_shape_cache,
+                placement_override=placement_override,
+            )
+            if resolved_pts:
+                _update_blender_curve(annotation, resolved_pts)
+    finally:
+        _dim_handler_running = False

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

@@ -170,6 +170,7 @@ def format_distance(
     precision=None,
     decimal_places=None,
     suppress_zero_inches=False,
+    suppress_zero_feet=False,
     in_unit_length=False,
     custom_unit=None,
 ):
@@ -310,10 +311,10 @@ def format_distance(
             tx_dist = ""
             if feet:
                 tx_dist += str(feet) + "'"
-            if not feet and not add_inches:
+            if not feet and not add_inches and not suppress_zero_feet:
                 tx_dist += str(feet) + "'"
 
-            if not feet and add_inches:
+            if not feet and add_inches and unit_length != "INCHES" and not suppress_zero_feet:
                 if value < 0:
                     tx_dist += "-0' - "
                 else:

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

@@ -986,6 +986,160 @@ def update_sheet_data(self, context):
     SheetsData.is_loaded = False
 
 
+def _update_force_perpendicular(self, context):
+    """Apply ForcePerpendicularToFace to all selected dimension annotations and regenerate them."""
+    import json
+    import numpy as np
+    import ifcopenshell.util.element
+    import ifcopenshell.api.pset
+    import ifcopenshell.api.drawing as drawing_api
+    import bonsai.tool as tool
+
+    file = tool.Ifc.get()
+    if not file:
+        return
+
+    new_value = self.force_perpendicular_to_face
+    _DIM_TYPES = frozenset(("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"))
+
+    targets = []
+    for obj in context.selected_objects:
+        element = tool.Ifc.get_entity(obj)
+        if not element or not element.is_a("IfcAnnotation"):
+            continue
+        if ifcopenshell.util.element.get_predefined_type(element) not in _DIM_TYPES:
+            continue
+        pset_data = ifcopenshell.util.element.get_pset(element, "BBIM_Dimension")
+        if not pset_data:
+            continue
+        targets.append((obj, element, pset_data))
+
+    if not targets:
+        return
+
+    from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+    for obj, element, pset_data in targets:
+        pset_entity = file.by_id(pset_data["id"])
+        ifcopenshell.api.pset.edit_pset(file, pset=pset_entity, properties={"ForcePerpendicularToFace": new_value})
+
+        anchors = json.loads(pset_data.get("Anchors") or "[]")
+        placement_override = {}
+        for a in anchors:
+            guid = a.get("guid")
+            if not guid:
+                continue
+            try:
+                elem = file.by_guid(guid)
+                elem_obj = tool.Ifc.get_object(elem)
+                if elem_obj:
+                    placement_override[elem.id()] = np.array(elem_obj.matrix_world)
+            except Exception:
+                pass
+
+        resolved_pts = drawing_api.regenerate_dimension(file, element, placement_override=placement_override)
+        if resolved_pts:
+            _update_blender_curve(element, resolved_pts)
+
+
+def _get_line_position(self) -> float:
+    """Return LinePosition from the active annotation's BBIM_Dimension pset.
+
+    Falls back to the natural anchor projection when LinePosition has not been
+    explicitly set, so the field always shows a meaningful value.
+    """
+    import math
+    import json
+    try:
+        import bpy as _bpy
+        import ifcopenshell.util.element as _ue
+        import bonsai.tool as _tool
+        obj = getattr(_bpy.context, "active_object", None)
+        if obj:
+            element = _tool.Ifc.get_entity(obj)
+            if element and element.is_a("IfcAnnotation"):
+                pset = _ue.get_pset(element, "BBIM_Dimension")
+                if pset:
+                    stored = pset.get("LinePosition")
+                    if stored is not None:
+                        return float(stored)
+                    raw = pset.get("Anchors")
+                    if raw:
+                        anchors = json.loads(raw)
+                        if len(anchors) >= 2 and anchors[0].get("pt") and anchors[1].get("pt"):
+                            a, b = anchors[0]["pt"], anchors[1]["pt"]
+                            dx, dy, dz = b[0] - a[0], b[1] - a[1], b[2] - a[2]
+                            m = math.sqrt(dx * dx + dy * dy + dz * dz)
+                            if m > 1e-10:
+                                ddx, ddy, ddz = dx / m, dy / m, dz / m
+                                # cross(world_Z=(0,0,1), dim_dir) = (-ddy, ddx, 0)
+                                ox, oy, oz = -ddy, ddx, 0.0
+                                om = math.sqrt(ox * ox + oy * oy)
+                                if om > 1e-6:
+                                    od = (ox / om, oy / om, 0.0)
+                                    pt = anchors[0]["pt"]
+                                    return float(pt[0] * od[0] + pt[1] * od[1])
+    except Exception:
+        pass
+    return 0.0
+
+
+def _set_line_position(self, value: float) -> None:
+    """Write LinePosition to all selected dimension annotations and regenerate."""
+    import json
+    import numpy as np
+    import ifcopenshell.util.element
+    import ifcopenshell.api.pset
+    import ifcopenshell.api.drawing as drawing_api
+    import bonsai.tool as tool
+
+    file = tool.Ifc.get()
+    if not file:
+        return
+
+    _DIM_TYPES = frozenset(("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"))
+
+    targets = []
+    import bpy as _bpy
+    for obj in getattr(_bpy.context, "selected_objects", []):
+        element = tool.Ifc.get_entity(obj)
+        if not element or not element.is_a("IfcAnnotation"):
+            continue
+        if ifcopenshell.util.element.get_predefined_type(element) not in _DIM_TYPES:
+            continue
+        pset_data = ifcopenshell.util.element.get_pset(element, "BBIM_Dimension")
+        if not pset_data:
+            continue
+        targets.append((obj, element, pset_data))
+
+    if not targets:
+        return
+
+    from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+    for obj, element, pset_data in targets:
+        pset_entity = file.by_id(pset_data["id"])
+        ifcopenshell.api.pset.edit_pset(file, pset=pset_entity, properties={"LinePosition": value})
+
+        anchors = json.loads(pset_data.get("Anchors") or "[]")
+        placement_override = {}
+        for a in anchors:
+            guid = a.get("guid")
+            if not guid:
+                continue
+            try:
+                elem = file.by_guid(guid)
+                elem_obj = tool.Ifc.get_object(elem)
+                if elem_obj:
+                    placement_override[elem.id()] = np.array(elem_obj.matrix_world)
+            except Exception:
+                pass
+
+        resolved_pts = drawing_api.regenerate_dimension(file, element, placement_override=placement_override)
+        if resolved_pts:
+            _update_blender_curve(element, resolved_pts)
+
+
 class BIMAnnotationProperties(PropertyGroup):
     object_type: bpy.props.EnumProperty(
         name="Annotation Object Type", items=annotation_classes, default="TEXT", update=update_annotation_object_type
@@ -999,6 +1153,25 @@ class BIMAnnotationProperties(PropertyGroup):
     )
     is_adding_type: bpy.props.BoolProperty(default=False)
     type_name: bpy.props.StringProperty(name="Name", default="TYPEX")
+    force_perpendicular_to_face: bpy.props.BoolProperty(
+        name="Force ⊥ to Face",
+        description="Constrain dimension vertices to the face normal of the first anchor. When dimensions are selected, toggling this updates them all.",
+        default=False,
+        update=_update_force_perpendicular,
+    )
+    line_position: bpy.props.FloatProperty(
+        name="Line Position",
+        description="Absolute world position of the dimension line along the horizontal axis perpendicular to the dimension. The line is held at this fixed global coordinate even when the measured geometry moves. Updates all selected dimensions.",
+        unit="LENGTH",
+        get=_get_line_position,
+        set=_set_line_position,
+    )
+    is_manual_reference: bpy.props.BoolProperty(
+        name="Is a Reference",
+        default=False,
+        description="Place as a manual reference tag (IsManualDrawingReference). "
+        "Exempt from automatic drawing regeneration. Optionally link to a drawing or external reference.",
+    )
     tag_rotation_mode: bpy.props.EnumProperty(
         name="Tag Rotation Mode",
         description="How to orient the tag relative to the tagged object",
@@ -1019,3 +1192,4 @@ class BIMAnnotationProperties(PropertyGroup):
         create_representation_for_type: bool
         is_adding_type: bool
         type_name: str
+        is_manual_reference: bool

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

@@ -872,7 +872,11 @@ class SvgWriter:
 
         v1 = self.project_point_onto_camera(obj.matrix_world @ Vector((0, 0, 0)))
         v2 = self.project_point_onto_camera(obj.matrix_world @ Vector((0, 0, -1)))
-        angle = -math.degrees((v2 - v1).xy.angle_signed(Vector((0, 1))))
+        delta = (v2 - v1).xy
+        if delta.length <= 1e-6:
+            v2 = self.project_point_onto_camera(obj.matrix_world @ Vector((1, 0, 0)))
+            delta = (v2 - v1).xy
+        angle = -math.degrees(delta.angle_signed(Vector((0, 1)))) if delta.length > 1e-6 else 90.0
 
         transform = "rotate({}, {}, {})".format(angle, *symbol_position_svg.xy)
 
@@ -892,9 +896,35 @@ class SvgWriter:
         )
 
     def get_reference_and_sheet_id_from_annotation(self, element: ifcopenshell.entity_instance) -> tuple[str, str]:
-        reference_id = "-"
-        sheet_id = "-"
+        is_ifc2x3 = tool.Ifc.get_schema() == "IFC2X3"
+
+        # Document-reference annotations link to an IfcDocumentInformation via
+        # IfcRelAssociatesDocument rather than to a drawing product.
+        if tool.Drawing.is_document_reference(element):
+            doc_info = tool.Drawing.get_annotation_reference_doc(element)
+            if not doc_info:
+                return ("-", "-")
+            ext_location = tool.Drawing.get_path_with_ext(
+                (doc_info.DocumentReferences[0].Location if is_ifc2x3 else doc_info.HasDocumentReferences[0].Location),
+                "svg",
+            ) if (doc_info.DocumentReferences if is_ifc2x3 else doc_info.HasDocumentReferences) else None
+            if not ext_location:
+                return ("-", "-")
+            for sheet_reference in tool.Ifc.get().by_type("IfcDocumentReference"):
+                if tool.Drawing.get_reference_description(sheet_reference) != "REFERENCE":
+                    continue
+                if sheet_reference.Location != ext_location:
+                    continue
+                sheet = tool.Drawing.get_reference_document(sheet_reference)
+                if sheet:
+                    if is_ifc2x3:
+                        return (sheet_reference.ItemReference or "-", sheet.DocumentId or "-")
+                    return (sheet_reference.Identification or "-", sheet.Identification or "-")
+            return ("-", "-")
+
         drawing = tool.Drawing.get_annotation_element(element)
+        if not drawing:
+            return ("-", "-")
         reference = tool.Drawing.get_drawing_reference(drawing)
         if reference:
             for sheet_reference in tool.Ifc.get().by_type("IfcDocumentReference"):
@@ -903,13 +933,9 @@ 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 "-"
-                    return (reference_id, sheet_id)
+                    if is_ifc2x3:
+                        return (sheet_reference.ItemReference or "-", sheet.DocumentId or "-")
+                    return (sheet_reference.Identification or "-", sheet.Identification or "-")
                 break
         return ("-", "-")
 
@@ -1371,14 +1397,18 @@ class SvgWriter:
 
             def get_text():
                 radius = (points[-1].co - points[-2].co).length
-                radius = helper.format_distance(
-                    radius,
-                    precision=self.precision,
-                    decimal_places=self.decimal_places,
-                    custom_unit=dimension_data["custom_unit"],
-                )
-                text = f"R{radius}"
-                return text
+                units_to_format = dimension_data["custom_units"] if dimension_data["custom_units"] else [None]
+                parts = [
+                    helper.format_distance(
+                        radius,
+                        precision=self.precision,
+                        decimal_places=self.decimal_places,
+                        suppress_zero_feet=dimension_data["suppress_zero_feet"],
+                        custom_unit=unit,
+                    )
+                    for unit in units_to_format
+                ]
+                return "R" + dimension_data["separator"].join(str(p) for p in parts)
 
             self.draw_dimension_text(
                 get_text, tag, dimension_data, text_position=text_position, class_str="RADIUS", box_alignment="center"
@@ -1503,10 +1533,12 @@ class SvgWriter:
                     text_format=lambda x: "D" + x,
                     show_description_only=dimension_data["show_description_only"],
                     suppress_zero_inches=dimension_data["suppress_zero_inches"],
+                    suppress_zero_feet=dimension_data["suppress_zero_feet"],
                     text_prefix=dimension_data["text_prefix"],
                     text_suffix=dimension_data["text_suffix"],
                     fill_bg=dimension_data["fill_bg"],
-                    custom_unit=dimension_data["custom_unit"],
+                    custom_units=dimension_data["custom_units"],
+                    separator=dimension_data["separator"],
                 )
 
     def draw_dimension_annotations(self, obj: bpy.types.Object) -> None:
@@ -1517,11 +1549,15 @@ class SvgWriter:
         dimension_data = DecoratorData.get_dimension_data(obj)
 
         assert isinstance(obj.data, bpy.types.Curve)
+        is_ordinate = dimension_data["is_ordinate"]
         for spline in obj.data.splines:
             points = self.get_spline_points(spline)
+            ordinate_total = 0.0
             for i in range(len(points) - 1):
                 v0_global = matrix_world @ points[i].co.xyz
                 v1_global = matrix_world @ points[i + 1].co.xyz
+                if is_ordinate:
+                    ordinate_total += (v1_global - v0_global).length
                 self.draw_dimension_annotation(
                     v0_global,
                     v1_global,
@@ -1529,10 +1565,13 @@ class SvgWriter:
                     dimension_text=dimension_text,
                     show_description_only=dimension_data["show_description_only"],
                     suppress_zero_inches=dimension_data["suppress_zero_inches"],
+                    suppress_zero_feet=dimension_data["suppress_zero_feet"],
                     text_prefix=dimension_data["text_prefix"],
                     text_suffix=dimension_data["text_suffix"],
                     fill_bg=dimension_data["fill_bg"],
-                    custom_unit=dimension_data["custom_unit"],
+                    custom_units=dimension_data["custom_units"],
+                    separator=dimension_data["separator"],
+                    distance_override=ordinate_total if is_ordinate else None,
                 )
 
     def draw_measureit_arch_dimension_annotations(self) -> None:
@@ -1556,10 +1595,13 @@ class SvgWriter:
         text_format=lambda x: x,
         show_description_only=False,
         suppress_zero_inches=False,
+        suppress_zero_feet=False,
         text_prefix="",
         text_suffix="",
         fill_bg=False,
-        custom_unit=None,
+        custom_units=None,
+        separator=" / ",
+        distance_override=None,
     ) -> None:
         offset = Vector([self.raw_width, self.raw_height]) / 2
         v0 = self.project_point_onto_camera(v0_global)
@@ -1572,7 +1614,10 @@ class SvgWriter:
         sheet_dimension = (end - start).length
 
         # if annotation can't fit offset text to the right of marker
-        text_position = mid if sheet_dimension > 5 else (end + (3 * vector.normalized()))
+        if distance_override is not None:
+            text_position = end
+        else:
+            text_position = mid if sheet_dimension > 5 else (end + (3 * vector.normalized()))
         angle = math.degrees(vector.angle_signed(Vector((1, 0))))
 
         line = self.svg.line(start=start, end=end, class_=" ".join(classes))
@@ -1587,15 +1632,20 @@ class SvgWriter:
         }
 
         if not show_description_only:
-            dimension = (v1_global - v0_global).length
-            dimension = helper.format_distance(
-                dimension,
-                precision=self.precision,
-                decimal_places=self.decimal_places,
-                suppress_zero_inches=suppress_zero_inches,
-                custom_unit=custom_unit,
-            )
-            text = text_prefix + str(dimension) + text_suffix
+            dimension = distance_override if distance_override is not None else (v1_global - v0_global).length
+            units_to_format = custom_units if custom_units else [None]
+            parts = [
+                helper.format_distance(
+                    dimension,
+                    precision=self.precision,
+                    decimal_places=self.decimal_places,
+                    suppress_zero_inches=suppress_zero_inches,
+                    suppress_zero_feet=suppress_zero_feet,
+                    custom_unit=unit,
+                )
+                for unit in units_to_format
+            ]
+            text = text_prefix + separator.join(str(p) for p in parts) + text_suffix
         else:
             if not dimension_text:
                 return
@@ -1603,8 +1653,8 @@ class SvgWriter:
 
         text_tags += self.create_text_tag(
             text,
-            text_position + perpendicular,
-            box_alignment="bottom-middle",
+            text_position + perpendicular + (Vector((0, 1.5)) if distance_override is not None else Vector((0, 0))),
+            box_alignment="bottom-right" if distance_override is not None else "bottom-middle",
             multiline_to_bottom=False,
             **text_tag_kwargs,
         )
@@ -1612,8 +1662,8 @@ class SvgWriter:
         if not show_description_only and dimension_text:
             text_tags += self.create_text_tag(
                 dimension_text,
-                text_position - perpendicular,
-                box_alignment="top-middle",
+                text_position - perpendicular + (Vector((0, 1.5)) if distance_override is not None else Vector((0, 0))),
+                box_alignment="top-right" if distance_override is not None else "top-middle",
                 multiline_to_bottom=True,
                 **text_tag_kwargs,
             )

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

@@ -535,6 +535,17 @@ class BIM_PT_product_assignments(Panel):
 
         assert self.layout
         assert (obj := context.active_object)
+
+        element = tool.Ifc.get_entity(obj)
+        if element and tool.Drawing.is_manual_drawing_reference(element):
+            row = self.layout.row(align=True)
+            fallback = "No Reference Assigned" if element.ObjectType == "REFERENCE" else "No Drawing Assigned"
+            row.label(
+                text=ProductAssignmentsData.data["relating_product"] or fallback, icon="IMAGE_DATA"
+            )
+            row.operator("bim.assign_manual_drawing_reference", icon="GREASEPENCIL", text="")
+            return
+
         props = tool.Drawing.get_object_assigned_product_props(obj)
 
         if props.is_editing_product:
@@ -552,6 +563,7 @@ class BIM_PT_product_assignments(Panel):
             col.enabled = bool(ProductAssignmentsData.data["relating_product"])
 
 
+
 def get_category_icon(category_name):
     """Get appropriate icon for each category"""
     icons = {

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

@@ -114,7 +114,11 @@ class AnnotationTool(WorkSpaceTool):
     bl_description = "Gives you Annotation related superpowers"
     bl_icon = os.path.join(os.path.dirname(__file__), "ops.authoring.annotation")
     bl_widget = None
-    bl_keymap = tool.Blender.get_default_selection_keypmap() + (
+    bl_keymap = (
+        # Before view3d.select: tool keymaps take priority over the addon keymap
+        # where ClickNearestDimensionAnchor is also registered.
+        ("bim.click_nearest_dimension_anchor", {"type": "LEFTMOUSE", "value": "PRESS"}, None),
+    ) + tool.Blender.get_default_selection_keypmap() + (
         ("bim.annotation_hotkey", {"type": "A", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_A")]}),
         ("bim.annotation_hotkey", {"type": "C", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_C")]}),
         ("bim.annotation_hotkey", {"type": "E", "value": "PRESS", "shift": True}, {"properties": [("hotkey", "S_E")]}),
@@ -221,11 +225,29 @@ class AnnotationToolUI:
         props = tool.Drawing.get_document_props()
         row.prop(props, "should_draw_decorations", text="Viewport Annotations")
 
+    _DIMENSION_TYPES = frozenset(("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"))
+
     @classmethod
     def draw_edit_object_interface(cls, context):
-        if DecoratorData.get_text_data(bpy.context.active_object):
+        obj = bpy.context.active_object
+        if tool.Ifc.get_entity(obj) and DecoratorData.get_text_data(obj):
             add_layout_hotkey_operator(cls.layout, "Edit Text", "S_E", "")
 
+        obj = context.active_object
+        element = tool.Ifc.get_entity(obj) if obj else None
+        if element and element.is_a("IfcAnnotation"):
+            ptype = ifcopenshell.util.element.get_predefined_type(element)
+            if ptype in cls._DIMENSION_TYPES:
+                cls.layout.separator()
+                ann_props = tool.Drawing.get_annotation_props()
+                if ann_props.force_perpendicular_to_face:
+                    row = cls.layout.row(align=True)
+                    row.prop(ann_props, "line_position")
+                cls.layout.separator()
+                row = cls.layout.row(align=True)
+                op = row.operator("bim.regenerate_dimensions", icon="FILE_REFRESH", text="Regenerate")
+                op.active_only = True
+
     @classmethod
     def draw_type_selection_interface(cls):
         # shared by both sidebar and header
@@ -248,6 +270,15 @@ class AnnotationToolUI:
 
         add_layout_hotkey_operator(cls.layout, "Add", "S_A", "Create a new annotation")
 
+        if object_type in ("ELEVATION", "SECTION"):
+            row = cls.layout.row(align=True)
+            row.prop(cls.props, "is_manual_reference")
+
+        _DIMENSION_TYPES = {"DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL"}
+        if object_type in _DIMENSION_TYPES:
+            row = cls.layout.row(align=True)
+            row.prop(cls.props, "force_perpendicular_to_face")
+
         if object_type in tool.Drawing.ANNOTATION_TYPES_SUPPORT_SETUP:
             row = cls.layout.row(align=True)
             row.label(text="", icon="DRIVER_ROTATIONAL_DIFFERENCE")
@@ -330,9 +361,17 @@ class Hotkey(bpy.types.Operator, tool.Ifc.Operator):
         if created_objects:
             bpy.context.view_layer.objects.active = created_objects[-1]
 
+    _PARAMETRIC_DIMENSION_TYPES = frozenset(
+        ("DIMENSION", "RADIUS", "DIAMETER", "ANGLE", "PLAN_LEVEL", "SECTION_LEVEL")
+    )
+
     def hotkey_S_A(self):
-        if bpy.ops.bim.add_annotation.poll():
-            bpy.ops.bim.add_annotation()
+        props = tool.Drawing.get_annotation_props()
+        if props.object_type in self._PARAMETRIC_DIMENSION_TYPES:
+            if bpy.ops.bim.draw_parametric_dimension.poll():
+                bpy.ops.bim.draw_parametric_dimension("INVOKE_DEFAULT")
+        elif bpy.ops.bim.add_annotation.poll():
+            bpy.ops.bim.add_annotation("INVOKE_DEFAULT")
 
     def hotkey_S_E(self):
         if not bpy.context.active_object:

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

@@ -630,7 +630,7 @@ class EditAssignedMaterial(bpy.types.Operator, tool.Ifc.Operator):
                     slab.DumbSlabPlaner().regenerate_from_layer_set(layer_set)
 
             if material_set_usage.is_a("IfcMaterialProfileSetUsage"):
-                if "CardinalPoint" in attributes:
+                if "CardinalPoint" in attributes and attributes["CardinalPoint"] is not None:
                     attributes["CardinalPoint"] = int(attributes["CardinalPoint"])
                 ifcopenshell.api.material.edit_profile_usage(
                     self.file,
@@ -804,6 +804,8 @@ class EditMaterialSetItem(bpy.types.Operator, tool.Ifc.Operator):
             )
             slab.DumbSlabPlaner().regenerate_from_layer(layer)
             wall.DumbWallPlaner().regenerate_from_layer(layer)
+            from bonsai.bim.module.drawing.handler import regenerate_dims_for_layer
+            regenerate_dims_for_layer(self.file, layer)
         elif material.is_a("IfcMaterialProfileSet"):
             profile_def = None
             if mprops.profiles:

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

@@ -753,6 +753,8 @@ class PolylineDecorator:
         rv3d = region.data
 
         polyline_props = tool.Model.get_polyline_props()
+        if not polyline_props.snap_mouse_point:
+            return
         snap_prop = polyline_props.snap_mouse_point[0]
         mouse_point = Vector((snap_prop.x, snap_prop.y, snap_prop.z))
 
@@ -820,6 +822,8 @@ class PolylineDecorator:
         gpu.state.point_size_set(6)
 
         polyline_props = tool.Model.get_polyline_props()
+        if not polyline_props.snap_mouse_point:
+            return
         snap_prop = polyline_props.snap_mouse_point[0]
         # Point related to the mouse
         mouse_point = [Vector((snap_prop.x, snap_prop.y, snap_prop.z))]

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

@@ -461,14 +461,26 @@ class PolylineOperator:
         self.tool_state.axis_method = None
         self.tool_state.plane_method = None
         self.tool_state.mode = "Mouse"
-        tool.Raycast.clear_snap_objs()
+        # Do not call clear_snap_objs() here — create_snap_obj() validates stale
+        # entries per-object (vertex count + position check), so the BVH cache can
+        # safely persist across invocations. Clearing it caused an 11-second stall
+        # on every Shift+A because SnapObj rebuilds a pure-Python BVH tree.
         self.visible_objs = tool.Raycast.get_visible_objects(context)
         for obj in self.visible_objs:
             if bbox_2d := tool.Raycast.get_on_screen_2d_bounding_boxes(context, obj):
                 self.objs_2d_bbox.append(bbox_2d)
-        detected_snaps = tool.Snap.detect_snapping_points(context, event, self.objs_2d_bbox, self.tool_state)
-        self.snapping_points = tool.Snap.select_snapping_points(context, event, self.tool_state, detected_snaps)
+        self._init_snapping_points(context, event)
         tool.Polyline.calculate_distance_and_angle(context, self.input_ui, self.tool_state)
 
         tool.Blender.update_viewport()
         context.window_manager.modal_handler_add(self)
+
+    def _init_snapping_points(self, context: bpy.types.Context, event: bpy.types.Event) -> None:
+        """Populate self.snapping_points at operator start.
+
+        Override in subclasses to skip the full BVH snap detection when a cheap
+        placeholder is sufficient.  The default runs the full detection pass.
+        """
+        detected_snaps = tool.Snap.detect_snapping_points(context, event, self.objs_2d_bbox, self.tool_state)
+        self.snapping_points = tool.Snap.select_snapping_points(context, event, self.tool_state, detected_snaps)
+

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

@@ -468,14 +468,16 @@ class ChangeExtrusionXAngle(bpy.types.Operator, tool.Ifc.Operator):
                     existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, 0, tolerance=0.001) else existing_x_angle
                     existing_x_angle = 0 if tool.Cad.is_x(existing_x_angle, pi, tolerance=0.001) else existing_x_angle
 
-                    coord_list = builder.get_polyline_coords(extrusion.SweptArea.OuterCurve)
-                    coord_list = [
-                        (p[0], p[1] * abs(cos(existing_x_angle))) for p in coord_list
-                    ]  # Reset the transformation and returns to the original points with 0 degrees
-                    coord_list = [
-                        (p[0], p[1] * abs(1 / cos(x_angle))) for p in coord_list
-                    ]  # Apply the transformation for the new x_angle
-                    builder.set_polyline_coords(extrusion.SweptArea.OuterCurve, coord_list)
+                    profiles = extrusion.SweptArea.Profiles if extrusion.SweptArea.is_a("IfcCompositeProfileDef") else [extrusion.SweptArea]
+                    for profile in profiles:
+                        coord_list = builder.get_polyline_coords(profile.OuterCurve)
+                        coord_list = [
+                            (p[0], p[1] * abs(cos(existing_x_angle))) for p in coord_list
+                        ]  # Reset the transformation and returns to the original points with 0 degrees
+                        coord_list = [
+                            (p[0], p[1] * abs(1 / cos(x_angle))) for p in coord_list
+                        ]  # Apply the transformation for the new x_angle
+                        builder.set_polyline_coords(profile.OuterCurve, coord_list)
 
                     # The extrusion direction calculated previously default to the positive direction
                     # Here we set the extrusion direction to negative if that's the case

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

@@ -88,6 +88,44 @@ class DisablePsetEditing(bpy.types.Operator, tool.Ifc.Operator):
         props.active_pset_type = "-"
 
 
+def _regenerate_parametric_dimension(file, annotation):
+    """Regenerate a single parametric dimension annotation after a pset edit."""
+    try:
+        import json
+        import numpy as np
+        import ifcopenshell.util.element
+        import ifcopenshell.api.drawing as drawing_api
+        import bonsai.tool as _tool
+        from bonsai.bim.module.drawing.operator import _update_blender_curve
+
+        pset_data = ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension")
+        if not pset_data or not pset_data.get("Anchors"):
+            return
+
+        anchors = json.loads(pset_data["Anchors"])
+        placement_override = {}
+        for a in anchors:
+            guid = a.get("guid")
+            if not guid:
+                continue
+            try:
+                elem = file.by_guid(guid)
+                elem_obj = _tool.Ifc.get_object(elem)
+                if elem_obj:
+                    placement_override[elem.id()] = np.array(elem_obj.matrix_world)
+            except Exception:
+                pass
+
+        resolved_pts = drawing_api.regenerate_dimension(
+            file, annotation, placement_override=placement_override
+        )
+        if resolved_pts:
+            _update_blender_curve(annotation, resolved_pts)
+    except Exception:
+        import traceback
+        traceback.print_exc()
+
+
 class EditPset(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.edit_pset"
     bl_label = "Edit Pset"
@@ -150,7 +188,12 @@ class EditPset(bpy.types.Operator, tool.Ifc.Operator):
             )
             if tool.Cost.has_schedules():
                 tool.Cost.update_cost_items(pset=pset)
+        is_bbim_dimension = props.active_pset_name == "BBIM_Dimension" and element.is_a("IfcAnnotation")
+
         bpy.ops.bim.disable_pset_editing(obj=self.obj, obj_type=self.obj_type)
+        if is_bbim_dimension:
+            _regenerate_parametric_dimension(self.file, element)
+
         tool.Blender.update_viewport()
 
 

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

@@ -118,6 +118,19 @@ def update_shader_graph(self: Union["Texture", "BIMStylesProperties"], context:
     tool.Loader.create_surface_style_with_textures(material, shading_data, textures_data)
 
 
+def _make_clear_null_updater(null_prop: str):
+    def _update(self: "BIMStylesProperties", context: bpy.types.Context) -> None:
+        self[null_prop] = False
+        update_shader_graph(self, context)
+
+    return _update
+
+
+update_diffuse_colour = _make_clear_null_updater("is_diffuse_colour_null")
+update_specular_colour = _make_clear_null_updater("is_specular_colour_null")
+update_specular_highlight_value = _make_clear_null_updater("is_specular_highlight_null")
+
+
 UV_MODES = [
     ("UV", "UV", _("Actual UV data presented on the geometry")),
     ("Generated", "Generated", _("Automatically-generated UV from the vertex positions of the mesh")),
@@ -221,24 +234,29 @@ class BIMStylesProperties(PropertyGroup):
     transparency: bpy.props.FloatProperty(
         name="Transparency", default=0.0, min=0.0, max=1.0, update=update_shader_graph
     )
-    # TODO: do something on null?
-    is_diffuse_colour_null: BoolProperty(name="Is Null")
+    is_diffuse_colour_null: BoolProperty(name="Is Null", update=update_shader_graph)
     diffuse_colour_class: EnumProperty(
         items=[(x, x, "") for x in get_args(ColourClass)],
         name="Diffuse Colour Class",
-        update=update_shader_graph,
+        update=update_diffuse_colour,
     )
     diffuse_colour: bpy.props.FloatVectorProperty(
-        name="Diffuse Colour", subtype="COLOR", default=(1, 1, 1), min=0.0, max=1.0, size=3, update=update_shader_graph
+        name="Diffuse Colour",
+        subtype="COLOR",
+        default=(1, 1, 1),
+        min=0.0,
+        max=1.0,
+        size=3,
+        update=update_diffuse_colour,
     )
     diffuse_colour_ratio: bpy.props.FloatProperty(
-        name="Diffuse Ratio", default=0.0, min=0.0, max=1.0, update=update_shader_graph
+        name="Diffuse Ratio", default=0.0, min=0.0, max=1.0, update=update_diffuse_colour
     )
-    is_specular_colour_null: BoolProperty(name="Is Null")
+    is_specular_colour_null: BoolProperty(name="Is Null", update=update_shader_graph)
     specular_colour_class: EnumProperty(
         items=[(x, x, "") for x in get_args(ColourClass)],
         name="Specular Colour Class",
-        update=update_shader_graph,
+        update=update_specular_colour,
         default="IfcNormalisedRatioMeasure",
     )
     specular_colour: bpy.props.FloatVectorProperty(
@@ -248,7 +266,7 @@ class BIMStylesProperties(PropertyGroup):
         min=0.0,
         max=1.0,
         size=3,
-        update=update_shader_graph,
+        update=update_specular_colour,
     )
     specular_colour_ratio: bpy.props.FloatProperty(
         name="Specular Ratio",
@@ -256,16 +274,16 @@ class BIMStylesProperties(PropertyGroup):
         default=0.0,
         min=0.0,
         max=1.0,
-        update=update_shader_graph,
+        update=update_specular_colour,
     )
-    is_specular_highlight_null: BoolProperty(name="Is Null")
+    is_specular_highlight_null: BoolProperty(name="Is Null", update=update_shader_graph)
     specular_highlight: bpy.props.FloatProperty(
         name="Specular Highlight",
         description="Used as Roughness value in PHYSICAL Reflectance Method",
         default=0.0,
         min=0.0,
         max=1.0,
-        update=update_shader_graph,
+        update=update_specular_highlight_value,
     )
     reflectance_method: EnumProperty(
         name="Reflectance Method",

src/bonsai/bonsai/core/drawing.py

@@ -503,6 +503,26 @@ def add_annotation(
     return obj
 
 
+def assign_manual_drawing_reference(
+    ifc: type[tool.Ifc],
+    drawing_tool: type[tool.Drawing],
+    element: ifcopenshell.entity_instance,
+    drawing: Optional[ifcopenshell.entity_instance],
+) -> None:
+    for existing in drawing_tool.get_assigned_product_workaround(element):
+        ifc.run("drawing.unassign_product", relating_product=existing, related_object=element)
+    if drawing:
+        ifc.run("drawing.assign_product", relating_product=drawing, related_object=element)
+
+
+def assign_manual_reference_document(
+    drawing_tool: type[tool.Drawing],
+    element: ifcopenshell.entity_instance,
+    document: Optional[ifcopenshell.entity_instance],
+) -> None:
+    drawing_tool.set_annotation_reference_doc(element, document)
+
+
 def build_schedule(drawing: type[tool.Drawing], schedule: ifcopenshell.entity_instance) -> None:
     drawing.create_svg_schedule(schedule)
     drawing.open_svg(drawing.get_path_with_ext(drawing.get_document_uri(schedule), "svg"))

src/bonsai/bonsai/tool/cost.py

@@ -987,7 +987,8 @@ class Cost(bonsai.core.tool.Cost):
     def disable_editing_cost_item_parent(cls) -> None:
         props = cls.get_cost_props()
         props.active_cost_item_id = 0
-        props.change_cost_item_parent = False
+        if props.change_cost_item_parent == True:
+            props.change_cost_item_parent = False
 
     @classmethod
     def load_cost_item_quantities(cls, cost_item: Optional[ifcopenshell.entity_instance] = None) -> None:

src/bonsai/bonsai/tool/drawing.py

@@ -111,6 +111,7 @@ class Drawing(bonsai.core.tool.Drawing):
         "FILL_AREA":     AnnotationObjectType("Fill Area",        "", "NODE_TEXTURE", "mesh"),
         "FALL":          AnnotationObjectType("Fall",             "", "SORT_ASC", "curve"),
         "IMAGE":         AnnotationObjectType("Image",            "Add reference image attached to the drawing", "TEXTURE", "mesh"),
+        "MANUAL_DRAWING_REFERENCE": AnnotationObjectType("Manual Drawing Reference", "Add manual elevation or section reference tag that will not be moved or deleted during drawing regeneration", "EMPTY_ARROWS", "empty"),
     }
     # fmt: on
 
@@ -177,6 +178,10 @@ class Drawing(bonsai.core.tool.Drawing):
 
     @classmethod
     def get_annotation_data_type(cls, object_type: str) -> ANNOTATION_DATA_TYPE:
+        if object_type == "ELEVATION":
+            return "empty"
+        if object_type == "SECTION":
+            return "mesh"
         return cls.ANNOTATION_TYPES_DATA[object_type].data_type
 
     @classmethod
@@ -207,6 +212,14 @@ class Drawing(bonsai.core.tool.Drawing):
             co_end = co1 + vec * scaled_length
             obj = annotation.Annotator.add_line_to_annotation(obj, co_end, co1)
             obj.matrix_world = obj.matrix_world @ Matrix.Rotation(math.radians(-90), 4, "Z")
+        elif object_type == "ELEVATION":
+            obj.matrix_world = Matrix.Translation(bpy.context.scene.cursor.location.copy()) @ Matrix.Rotation(
+                math.radians(90), 4, "X"
+            )
+        elif object_type == "SECTION":
+            camera = tool.Ifc.get_object(drawing)
+            obj.matrix_world = cls.get_default_annotation_matrix(camera)
+            obj = annotation.Annotator.add_line_to_annotation(obj)
         elif object_type != "TEXT":
             obj = annotation.Annotator.add_line_to_annotation(obj)
 
@@ -1538,9 +1551,17 @@ class Drawing(bonsai.core.tool.Drawing):
                 elements.append(element)
         return elements
 
+    @classmethod
+    def is_manual_drawing_reference(cls, element: ifcopenshell.entity_instance) -> bool:
+        return bool(ifcopenshell.util.element.get_pset(element, "EPset_Annotation", "IsManualDrawingReference"))
+
     @classmethod
     def is_auto_annotation(cls, element: ifcopenshell.entity_instance):
-        return element.is_a("IfcAnnotation") and element.ObjectType in ("GRID", "SECTION", "ELEVATION", "SECTION_LEVEL")
+        if not (element.is_a("IfcAnnotation") and element.ObjectType in ("GRID", "SECTION", "ELEVATION", "SECTION_LEVEL")):
+            return False
+        if ifcopenshell.util.element.get_pset(element, "EPset_Annotation", "IsManualDrawingReference"):
+            return False
+        return True
 
     @classmethod
     def get_drawing_reference_annotation(
@@ -1756,6 +1777,10 @@ class Drawing(bonsai.core.tool.Drawing):
             # For section/elevation views, elevate the segment vertically
             if not (points := helper.elevate_segment(bounds, [v1, v2])):
                 return
+        elif target_view == "MODEL_VIEW":
+            # For model views, clip to XY bounds and keep Z (3D line at true elevation)
+            if not (points := helper.clip_segment(bounds, [v1, v2])):
+                return
         else:
             return
 
@@ -1868,6 +1893,57 @@ class Drawing(bonsai.core.tool.Drawing):
             element.Name = elevation.Name or "Unnamed"
             return element
 
+    @classmethod
+    def set_manual_drawing_reference(cls, element: ifcopenshell.entity_instance) -> None:
+        ifc_file = tool.Ifc.get()
+        pset = tool.Pset.get_element_pset(element, "EPset_Annotation")
+        if not pset:
+            pset = ifcopenshell.api.pset.add_pset(ifc_file, product=element, name="EPset_Annotation")
+        ifcopenshell.api.pset.edit_pset(ifc_file, pset=pset, properties={"IsManualDrawingReference": True})
+
+    @classmethod
+    def is_document_reference(cls, element: ifcopenshell.entity_instance) -> bool:
+        """Return True if this annotation links to an external document (not a Bonsai drawing camera)."""
+        return bool(ifcopenshell.util.element.get_pset(element, "EPset_Annotation", "IsDocumentReference"))
+
+    @classmethod
+    def set_document_reference_flag(cls, element: ifcopenshell.entity_instance) -> None:
+        """Mark this annotation as pointing to an external document reference."""
+        ifc_file = tool.Ifc.get()
+        pset = tool.Pset.get_element_pset(element, "EPset_Annotation")
+        if not pset:
+            pset = ifcopenshell.api.pset.add_pset(ifc_file, product=element, name="EPset_Annotation")
+        ifcopenshell.api.pset.edit_pset(ifc_file, pset=pset, properties={"IsDocumentReference": True})
+
+    @classmethod
+    def get_annotation_reference_doc(
+        cls, element: ifcopenshell.entity_instance
+    ) -> Union[ifcopenshell.entity_instance, None]:
+        """Return the IfcDocumentInformation linked to a document-reference annotation."""
+        for rel in element.HasAssociations:
+            if rel.is_a("IfcRelAssociatesDocument"):
+                doc = rel.RelatingDocument
+                if doc.is_a("IfcDocumentInformation"):
+                    return doc
+        return None
+
+    @classmethod
+    def set_annotation_reference_doc(
+        cls,
+        element: ifcopenshell.entity_instance,
+        document: Union[ifcopenshell.entity_instance, None],
+    ) -> None:
+        """Associate (or clear) an IfcDocumentInformation on a document-reference annotation."""
+        ifc_file = tool.Ifc.get()
+        # Remove existing document associations on this annotation.
+        for rel in list(element.HasAssociations):
+            if rel.is_a("IfcRelAssociatesDocument"):
+                ifcopenshell.api.document.unassign_document(
+                    ifc_file, products=[element], document=rel.RelatingDocument
+                )
+        if document:
+            ifcopenshell.api.document.assign_document(ifc_file, products=[element], document=document)
+
     @classmethod
     def regenerate_elevation_reference_annotation(
         cls,

src/bonsai/bonsai/tool/raycast.py

@@ -890,17 +890,25 @@ class Raycast(bonsai.core.tool.Raycast):
             return None
         for i, snap_obj in enumerate(cls.snap_objs):
             if obj.name == snap_obj.obj.name:
-                # Handle objects modified while a modal operator is active.
-                # Example: adding a door or window alters the wall geometry.
+                # Fast O(1) invalidation: vertex count change (mesh edit) or
+                # world matrix change (object moved/rotated).
                 if len(obj.data.vertices) != len(snap_obj.verts_3d):
                     cls.snap_objs.pop(i)
                     snap_obj = SnapObj(obj)
                     cls.snap_objs.append(snap_obj)
-                for v1, v2 in zip(obj.data.vertices, snap_obj.verts_3d):
-                    if (obj.matrix_world @ v1.co) != v2:
+                    return snap_obj
+                if obj.matrix_world != snap_obj.matrix_world:
+                    cls.snap_objs.pop(i)
+                    snap_obj = SnapObj(obj)
+                    cls.snap_objs.append(snap_obj)
+                    return snap_obj
+                # Sample one vertex to catch mesh edits that preserve vertex count.
+                if obj.data.vertices and snap_obj.verts_3d:
+                    if (obj.matrix_world @ obj.data.vertices[0].co) != snap_obj.verts_3d[0]:
                         cls.snap_objs.pop(i)
                         snap_obj = SnapObj(obj)
                         cls.snap_objs.append(snap_obj)
+                        return snap_obj
                 return snap_obj
         snap_obj = SnapObj(obj)
         cls.snap_objs.append(snap_obj)
@@ -940,6 +948,7 @@ class SnapObj:
         self.root.edges = [e.index for e in obj.data.edges]
         self.split_box(self.root, 0)
         self.verts_3d = [obj.matrix_world @ v.co for v in obj.data.vertices]
+        self.matrix_world = obj.matrix_world.copy()
         self.snap_points = []
 
     def __clear_all__():

src/bonsai/bonsai/tool/style.py

@@ -203,6 +203,11 @@ class Style(bonsai.core.tool.Style):
 
         available_props = props.bl_rna.properties.keys()
         for prop_blender, prop_ifc in STYLE_PROPS_MAP.items():
+            null_prop_name = f"is_{prop_blender}_null"
+            if null_prop_name in available_props and getattr(props, null_prop_name):
+                surface_style_data[prop_ifc] = None
+                continue
+
             class_prop_name = f"{prop_blender}_class"
 
             # get detailed color properties if available

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

@@ -61,6 +61,8 @@ When Blender ships with a new Python version:
      - What to update
    * - ``.github/workflows/ci-lint.yaml``
      - ``MIN_BLENDER_PY_VERSION``
+   * - ``.github/scripts/publish-bonsai-releases.py``
+     - ``CURRENT_PYTHON_VERSION``
    * - ``src/bonsai/Makefile``
      - ``SUPPORTED_PYVERSIONS``
    * - ``src/bonsai/scripts/dev_environment.py``
@@ -73,6 +75,18 @@ Notes:
 
 - Typically all packages are released at once using the same version schema
 - The ``README.md`` badges can serve as a visual reference for what versions have been released
+- Corrective Release (if needed after a standard release):
+
+  - Create a new branch from the release tag (e.g., from the ``ifcopenshell-0.8.5`` tag)
+  - Update ``VERSION`` with the ``-post1`` suffix (e.g., ``0.8.5-post1``, **not** ``.post1``)
+  - The hyphen is required for semantic versioning compliance; Blender will not process ``.post1`` suffixes correctly
+  - Follow the standard release process for the corrective version
+
+- Multiple Blender Python Versions:
+
+  - Blender does not allow multiple builds for the same platform with different Python versions (e.g., cannot have both ``bonsai_py311-0.8.5-windows-x64.zip`` and ``bonsai_py313-0.8.5-windows-x64.zip``)
+  - Workaround: publish different Python versions as different extension versions (e.g., py313 as ``0.8.5`` and py311 as ``0.8.5-post1``)
+  - Set the maximum Blender version on the Blender extensions platform UI to prevent conflicts (e.g., set max version ``5.1.0`` for ``0.8.5-post1``, which restricts it to versions below 5.1.0)
 
 Things to update:
 
@@ -96,10 +110,13 @@ Things to update:
 - ``.github/workflows/ci-ifcsverchok.yml`` - release ifcsverchok Blender add-on in GitHub releases
 - ``.github/workflows/ci-ifctester-pypi.yml`` - release `ifctester <https://pypi.org/project/ifctester/>`_ to PyPI
 - ``.github/workflows/ci-pyodide-wasm-release.yml`` - release pyodide wasm wheel to `wasm-wheels <https://github.com/IfcOpenShell/wasm-wheels>`_
-- Release Bonsai Blender extension - zip files from ci-bonsai.yml releases should be uploaded manually to `Blender extensions platform <https://extensions.blender.org/add-ons/bonsai/>`_
+- ``.github/workflows/publish-bonsai-releases.yml`` - publish Bonsai Blender extension to `Blender extensions platform <https://extensions.blender.org/add-ons/bonsai/>`_
+
+  - ❗ Requires ``BLENDER_EXTENSIONS_TOKEN`` secret to be set - ❗ not yet configured
+
 - Publishing documentation and websites (see `website <https://github.com/IfcOpenShell/website>`_ repository):
 
   - `ifcopenshell-docs.yml` - builds and publishes IfcOpenShell documentation to `docs.ifcopenshell.org <https://docs.ifcopenshell.org>`_ (`ifcopenshell_org_docs <https://github.com/IfcOpenShell/ifcopenshell_org_docs>`_ repo)
   - `bonsai-docs.yml` - builds and publishes Bonsai documentation to `docs.bonsaibim.org <https://docs.bonsaibim.org>`_ (`bonsaibim_org_docs <https://github.com/IfcOpenShell/bonsaibim_org_docs>`_ repo)
-  - `main.yml` - publishes `bonsaibim.org <https://bonsaibim.org>`_ (`bonsaibim_org_static_html <https://github.com/IfcOpenShell/bonsaibim_org_static_html>`_ repo) and `ifcopenshell.org <https://ifcopenshell.org>`_ (`ifcopenshell_org_static_html <https://github.com/IfcOpenShell/ifcopenshell_org_static_html>`_ repo)
+  - `publish-websites.yml` - publishes `bonsaibim.org <https://bonsaibim.org>`_ (`bonsaibim_org_static_html <https://github.com/IfcOpenShell/bonsaibim_org_static_html>`_ repo) and `ifcopenshell.org <https://ifcopenshell.org>`_ (`ifcopenshell_org_static_html <https://github.com/IfcOpenShell/ifcopenshell_org_static_html>`_ repo)
 - ``VERSION`` to the release version - **UPDATE THIS LAST** as all workflows above typically depend on it to set the version correctly

src/bonsai/docs/reference/project_overview/project_info.rst

@@ -58,7 +58,7 @@ Fields
     Class** based on the IFC Schema version.
 
 **Unit System**
-  Choose between metric and imperial units of measurement when creating a project.
+  Choose between metric and imperial units of measurement when creating a project. Project data is stored in this Unit System and displayed according to e.g. Length Unit, Area Unit, Volume Unit. Properly changing the Unit System after project creation requires conversion. See `Blender Manual : Scene Properties : Units <https://docs.blender.org/manual/en/latest/scene_layout/scene/properties.html#units>`_ for a description of changing the display units e.g. from Feet to Adaptive (enable Separate Units option) for Feet-and-Inches.
 
 **Length Unit**
   Depending on the unit system, choose the default unit to be used for all length measurements. Lengths are used for moving objects around in the 3D scene, as well as lengths, widths, height, and depth quantity take-off data.

src/bonsai/test/tool/test_cost.py

@@ -0,0 +1,49 @@
+# Bonsai - OpenBIM Blender Add-on
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# 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/>.
+
+
+import test.bim.bootstrap
+import ifcopenshell.api.cost
+
+import bonsai.core.tool
+import bonsai.tool as tool
+import test.bim.bootstrap
+from test.bim.bootstrap import NewFile
+
+from bonsai.tool.cost import Cost as subject
+
+class TestImplementsTool(NewFile):
+    def test_run(self):
+        assert isinstance(subject(), bonsai.core.tool.Cost)
+
+class TestDisableEditingCostItemParent(NewFile):
+    def test_avoid_recursion_error(newfile, monkeypatch):
+        class DummyProps:
+            def __init__(self):
+                self.change_cost_item_parent = None
+                self.active_cost_item_id = 5
+
+        props = DummyProps()
+        monkeypatch.setattr(
+            "bonsai.tool.Cost.get_cost_props",
+            lambda: props
+        )
+        subject.disable_editing_cost_item_parent()
+        assert props.active_cost_item_id == 0
+        assert props.change_cost_item_parent is not False
+

src/common.mk

@@ -1,7 +1,7 @@
 SHELL := sh
 IS_STABLE:=FALSE
-PYTHON:=python3.11
-PIP:=pip3.11
+PYTHON:=python3
+PIP:=pip3
 VERSION:=$(shell cat ../../VERSION)
 VERSION_DATE:=$(shell date '+%y%m%d')
 SED:=sed -i

src/ifc5d/ifc5d/IFC4X3QtoBaseQuantitiesBlender.json

@@ -237,7 +237,7 @@
                     "Area": "get_net_side_area",
                     "Height": "get_height",
                     "Perimeter": "get_rectangular_perimeter",
-                    "Width": "get_length"
+                    "Width": "get_x"
                 }
             },
             "IfcDuctFitting + IfcDuctFittingType": {

src/ifcchat/ifc_worker.js

@@ -29,16 +29,7 @@ async function ensurePyodide() {
         const micropip = pyodide.pyimport("micropip");
         micropip.install("python-dateutil")
         
-        // Detect python minor version (3.12 vs 3.13) and pick a matching wheel.
-        const pyVer = pyodide.runPython(`
-import sys
-f"{sys.version_info.major}.{sys.version_info.minor}"
-    `);
-
-        const wheelUrl =
-            pyVer === "3.13"
-                ? "https://ifcopenshell.github.io/wasm-wheels/ifcopenshell-0.8.3+34a1bc6-cp313-cp313-emscripten_4_0_9_wasm32.whl"
-                : "https://ifcopenshell.github.io/wasm-wheels/ifcopenshell-0.8.2+d50e806-cp312-cp312-emscripten_3_1_58_wasm32.whl";
+        const wheelUrl = "https://ifcopenshell.github.io/wasm-wheels/ifcopenshell-0.8.5-cp313-cp313-pyodide_2025_0_wasm32.whl";
 
         await micropip.install(wheelUrl);
 

src/ifcgeom/function_item_evaluator.cpp

@@ -104,14 +104,6 @@ struct gradient_fn_evaluator : public fn_evaluator {
         auto xy = horizontal_evaluator_.evaluate(u);
         auto uz = vertical_evaluator_.evaluate(u);
 
-        // curvature is stored in row 3 - capture it and remove it from the xy and uz matrices
-        // so the matrix operations (ie multiplication) works correct.y
-        auto horizontal_curvature = xy.row(3);
-        xy.row(3) = Eigen::Vector4d(0, 0, 0, 1);
-
-        auto vertical_curvature = uz.row(3);
-        uz.row(3) = Eigen::Vector4d(0, 0, 0, 1);
-
         uz(0, 3) = 0.0;      // x is distance along. zero it out so it doesn't add to the x from horizontal
         uz.col(1).swap(uz.col(2)); // uz is 2D in distance along - y plane, swap y and z so elevations become z
         uz.row(1).swap(uz.row(2));
@@ -119,12 +111,6 @@ struct gradient_fn_evaluator : public fn_evaluator {
         Eigen::Matrix4d m;
         m = xy * uz; // combine horizontal and vertical
 
-        // Put curvature back into the solution matrix
-        // curvature for vertical is in column 0, need it to be in column 1
-        // so it doesn't add to curvature for horizontal
-        std::swap(vertical_curvature(0), vertical_curvature(1));
-        m.row(3) = horizontal_curvature + vertical_curvature;
-
         return m;
     }
 

src/ifcgeom/mapping/IfcPointByDistanceExpression.cpp

@@ -52,6 +52,15 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcPointByDistanceExpression* i
    if (inst->OffsetVertical().has_value()) {
        auto offset_vertical = inst->OffsetVertical().get() * length_unit_;
        o += offset_vertical * z;
+
+       auto tmp1 = (z * offset_vertical).eval();
+       auto tmp2 = (Eigen::Vector3d(0, 0, 1) * offset_vertical).eval();
+       auto tmp3 = (tmp1 - tmp2).eval();
+
+       std::ostringstream oss;
+       oss << "local z: " << z.x() << "," << z.y() << "," << z.z() << "; delta: " << tmp3.x() << "," << tmp3.y() << "," << tmp3.z();
+       auto osss = oss.str();
+       std::wcout << osss.c_str() << std::endl;
    }
 
    if (inst->OffsetLongitudinal().has_value()) {

src/ifcgeom/mapping/mapping.cpp

@@ -562,6 +562,7 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcMaterial* material) {
             }
             // Check if it's failed or just some unsupported case.
             if (failed_on_purpose_.find(styled_item) == failed_on_purpose_.end()) {
+                failed_on_purpose_.insert(material);
                 return nullptr;
             }
             Logger::Warning("Skipping unsupported material style for material: ", material);
@@ -569,6 +570,7 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcMaterial* material) {
     }
 
     // When material does not have a representation we don't create a style from it
+    failed_on_purpose_.insert(material);
     return nullptr;
 
     /*

src/ifcopenshell-python/Makefile

@@ -5,8 +5,8 @@ VERSION_DATE:=$(shell date '+%y%m%d')
 PYVERSION:=py311
 PLATFORM:=linux64
 
-PYTHON:=python3.11
-PIP:=pip3.11
+PYTHON:=python3
+PIP:=pip3
 SED:=sed -i
 VENV_ACTIVATE:=bin/activate
 

src/ifcopenshell-python/ifcopenshell/api/cost/remove_cost_item.py

@@ -51,7 +51,7 @@ def remove_cost_item(file: ifcopenshell.file, cost_item: ifcopenshell.entity_ins
                 if history:
                     ifcopenshell.util.element.remove_deep2(file, history)
         elif inverse.is_a("IfcRelAssignsToControl"):
-            if len(inverse.RelatedObjects) >= 2 or inverse.RelatingControl == cost_item:
+            if len(inverse.RelatedObjects) >= 2:
                 continue
             history = inverse.OwnerHistory
             file.remove(inverse)

src/ifcopenshell-python/ifcopenshell/api/drawing/__init__.py

@@ -25,12 +25,24 @@ annotations may have relationships which indicate smart data being populated.
 from .. import wrap_usecases
 from .assign_product import assign_product
 from .edit_text_literal import edit_text_literal
+from .regenerate_dimension import regenerate_dimension, get_dimension_segment_lengths
+from .resolve_anchor import build_anchor_from_hit, build_anchor_from_layer_boundary, build_anchor_from_profile_vert, build_anchor_from_profile_edge, get_layer_snap_candidates, get_profile_snap_candidates, make_world_anchor, resolve_anchor
 from .unassign_product import unassign_product
 
 wrap_usecases(__path__, __name__)
 
 __all__ = [
     "assign_product",
+    "build_anchor_from_hit",
+    "build_anchor_from_layer_boundary",
+    "build_anchor_from_profile_edge",
+    "build_anchor_from_profile_vert",
     "edit_text_literal",
+    "get_dimension_segment_lengths",
+    "get_layer_snap_candidates",
+    "get_profile_snap_candidates",
+    "make_world_anchor",
+    "regenerate_dimension",
+    "resolve_anchor",
     "unassign_product",
 ]

src/ifcopenshell-python/ifcopenshell/api/drawing/regenerate_dimension.py

@@ -0,0 +1,383 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Regenerate a parametric dimension annotation from its BBIM_Dimension anchors.
+
+This module operates purely on IFC data.  It:
+  1. Reads the ``Anchors`` JSON array from the ``BBIM_Dimension`` pset on an
+     ``IfcAnnotation``.
+  2. Resolves each anchor to a world-space point (IFC project units) using
+     ``resolve_anchor``.
+  3. Computes per-segment distances and updates (or creates) the linked
+     ``IfcMetric`` + ``IfcRelAssociatesConstraint`` entities.
+  4. Returns the ordered list of resolved world-space points so that the
+     Bonsai operator layer can update the Blender curve object.
+
+Updating the Blender curve (converting IFC world coords → annotation local
+coords) is the *caller's* responsibility and does **not** happen here.
+"""
+
+from __future__ import annotations
+
+import json
+import math
+from typing import Optional
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.api.pset
+import ifcopenshell.geom
+import ifcopenshell.guid
+import ifcopenshell.util.element
+
+from .resolve_anchor import resolve_anchor
+
+
+_PSET_NAME = "BBIM_Dimension"
+_METRIC_INTENT_PREFIX = "PARAMETRIC_DIMENSION_SEG_"
+
+
+def regenerate_dimension(
+    file: ifcopenshell.file,
+    annotation: ifcopenshell.entity_instance,
+    settings: Optional[ifcopenshell.geom.settings] = None,
+    shape_cache: Optional[dict] = None,
+    placement_override: Optional[dict] = None,
+) -> list[tuple[float, float, float]]:
+    """Regenerate a parametric dimension from its stored anchor references.
+
+    Resolves every anchor in ``BBIM_Dimension.Anchors``, updates the
+    per-segment ``IfcMetric`` values (creating them when absent), and returns
+    the resolved world-space points in metres.
+
+    :param file: The open IFC file.
+    :param annotation: An ``IfcAnnotation`` with a ``BBIM_Dimension`` pset.
+    :param settings: Geometry settings for tessellation (shared across calls).
+    :param shape_cache: Shape cache dict (shared across calls for performance).
+    :param placement_override: Optional dict mapping element STEP id → 4×4 numpy
+        matrix (metres, row-major).  Pass ``{elem.id(): np.array(obj.matrix_world)}``
+        for each referenced element so that viewport moves not yet synced to the
+        IFC ``ObjectPlacement`` are reflected.  See ``resolve_anchor`` for details.
+    :return: Ordered list of ``(x, y, z)`` tuples, one per anchor.
+             Empty list if the pset is missing or malformed.
+    """
+    pset_data = ifcopenshell.util.element.get_pset(annotation, _PSET_NAME)
+    if not pset_data or "Anchors" not in pset_data:
+        return []
+
+    try:
+        anchors: list[dict] = json.loads(pset_data["Anchors"])
+    except (json.JSONDecodeError, TypeError):
+        return []
+
+    if not anchors:
+        return []
+
+    if shape_cache is None:
+        shape_cache = {}
+
+    resolved: list[Optional[tuple]] = []
+    for anchor in anchors:
+        pt = resolve_anchor(file, anchor, settings, shape_cache, placement_override)
+        if pt is None:
+            pt = tuple(anchor["pt"]) if anchor.get("pt") else (0.0, 0.0, 0.0)
+        resolved.append(pt)
+        anchor["pt"] = list(pt)
+
+    # ForcePerpendicularToFace: project vertices 1…n onto the line through
+    # pt[0] in the direction of anchor[0]'s face normal, so the polyline is
+    # constrained perpendicular to the face the first vertex is anchored to.
+    if pset_data.get("ForcePerpendicularToFace") and len(resolved) >= 2 and resolved[0] is not None:
+        normal = _get_anchor_face_normal_world(file, anchors[0], placement_override)
+        if normal:
+            base = resolved[0]
+            for i in range(1, len(resolved)):
+                if resolved[i] is None:
+                    continue
+                pt = resolved[i]
+                t = ((pt[0] - base[0]) * normal[0]
+                     + (pt[1] - base[1]) * normal[1]
+                     + (pt[2] - base[2]) * normal[2])
+                resolved[i] = (base[0] + t * normal[0],
+                                base[1] + t * normal[1],
+                                base[2] + t * normal[2])
+                anchors[i]["pt"] = list(resolved[i])
+
+    pset_entity_id = pset_data.get("id")
+    if pset_entity_id:
+        pset_entity = file.by_id(pset_entity_id)
+        ifcopenshell.api.pset.edit_pset(
+            file,
+            pset=pset_entity,
+            properties={"Anchors": json.dumps(anchors)},
+        )
+
+    n_segments = len(resolved) - 1
+    if n_segments >= 1:
+        existing_metrics = _get_segment_metrics(file, annotation)
+        _sync_segment_metrics(file, annotation, resolved, existing_metrics)
+
+    # LinePosition: project all points to a fixed absolute world coordinate along the
+    # horizontal offset axis (perpendicular to the dimension direction).  Applied after
+    # the pset write so anchor["pt"] always stores the true geometry surface hit.
+    # Because it is absolute, the dimension line stays put even if the geometry moves.
+    # Only active when ForcePerpendicularToFace is also set — the two are semantically coupled.
+    line_position = pset_data.get("LinePosition")
+    if line_position is not None and pset_data.get("ForcePerpendicularToFace") and resolved:
+        face_normal = _get_anchor_face_normal_world(file, anchors[0], placement_override)
+        offset_dir = _get_line_offset_direction(face_normal, [pt for pt in resolved if pt is not None])
+        if offset_dir:
+            resolved = [
+                _project_to_line_position(pt, offset_dir, float(line_position)) if pt is not None else None
+                for pt in resolved
+            ]
+
+    return [pt for pt in resolved if pt is not None]
+
+
+def get_dimension_segment_lengths(
+    file: ifcopenshell.file,
+    annotation: ifcopenshell.entity_instance,
+) -> list[float]:
+    """Return the segment lengths for a parametric dimension from stored anchor pts.
+
+    Distances are computed from the cached ``pt`` fields in ``BBIM_Dimension.Anchors``
+    (in metres, matching ifcopenshell.geom output).  Returns an empty list if the pset
+    is absent or malformed.
+    """
+    pset_data = ifcopenshell.util.element.get_pset(annotation, _PSET_NAME)
+    if not pset_data or not pset_data.get("Anchors"):
+        return []
+    try:
+        anchors: list[dict] = json.loads(pset_data["Anchors"])
+    except Exception:
+        return []
+    lengths: list[float] = []
+    for i in range(len(anchors) - 1):
+        pt_a = anchors[i].get("pt")
+        pt_b = anchors[i + 1].get("pt")
+        if pt_a and pt_b:
+            lengths.append(_dist(tuple(pt_a), tuple(pt_b)))
+        else:
+            lengths.append(0.0)
+    return lengths
+
+
+# ---------------------------------------------------------------------------
+# IfcMetric / IfcRelAssociatesConstraint management
+# ---------------------------------------------------------------------------
+
+
+def _get_segment_metrics(
+    file: ifcopenshell.file,
+    annotation: ifcopenshell.entity_instance,
+) -> dict[int, ifcopenshell.entity_instance]:
+    """Return {segment_index: IfcMetric} for all constraint rels on the annotation."""
+    metrics: dict[int, ifcopenshell.entity_instance] = {}
+    for rel in annotation.HasAssociations:
+        if not rel.is_a("IfcRelAssociatesConstraint"):
+            continue
+        intent: str = rel.Intent or ""
+        if not intent.startswith(_METRIC_INTENT_PREFIX):
+            continue
+        try:
+            seg_idx = int(intent[len(_METRIC_INTENT_PREFIX):])
+        except ValueError:
+            continue
+        constraint = rel.RelatingConstraint
+        if constraint.is_a("IfcMetric"):
+            metrics[seg_idx] = constraint
+    return metrics
+
+
+def _sync_segment_metrics(
+    file: ifcopenshell.file,
+    annotation: ifcopenshell.entity_instance,
+    resolved_pts: list[tuple],
+    existing: dict[int, ifcopenshell.entity_instance],
+) -> None:
+    """Create missing and update existing IfcMetric entities for each segment."""
+    n_segments = len(resolved_pts) - 1
+    seen_guids: set[str] = set()
+
+    # Build a lookup of which elements are at each anchor endpoint
+    pset_data = ifcopenshell.util.element.get_pset(annotation, _PSET_NAME)
+    anchors: list[dict] = []
+    if pset_data and pset_data.get("Anchors"):
+        try:
+            anchors = json.loads(pset_data["Anchors"])
+        except Exception:
+            pass
+
+    for seg_idx in range(n_segments):
+        if seg_idx in existing:
+            pass  # metric already exists; association is still valid
+        else:
+            # Create new IfcMetric + IfcRelAssociatesConstraint
+            # DataValue is IfcMetricValueSelect (entity-only SELECT in IFC4) — omit it;
+            # the measured distance is derivable from the anchor pt fields.
+            metric = file.create_entity(
+                "IfcMetric",
+                Name=f"seg_{seg_idx}",
+                ConstraintGrade="ADVISORY",
+                Benchmark="EQUALTO",
+            )
+            # Gather related products for this segment (the two anchor elements)
+            related: list[ifcopenshell.entity_instance] = [annotation]
+            for anchor_idx in (seg_idx, seg_idx + 1):
+                if anchor_idx < len(anchors):
+                    guid = anchors[anchor_idx].get("guid")
+                    if guid and guid not in seen_guids:
+                        try:
+                            elem = file.by_guid(guid)
+                            related.append(elem)
+                            seen_guids.add(guid)
+                        except Exception:
+                            pass
+
+            file.create_entity(
+                "IfcRelAssociatesConstraint",
+                GlobalId=ifcopenshell.guid.new(),
+                OwnerHistory=ifcopenshell.api.owner.create_owner_history(file),
+                Intent=f"{_METRIC_INTENT_PREFIX}{seg_idx}",
+                RelatingConstraint=metric,
+                RelatedObjects=related,
+            )
+
+    # Remove orphaned metrics for segments that no longer exist
+    for seg_idx, metric in existing.items():
+        if seg_idx >= n_segments:
+            for rel in file.get_inverse(metric):
+                if rel.is_a("IfcRelAssociatesConstraint"):
+                    file.remove(rel)
+            file.remove(metric)
+
+
+def _dist(a: tuple, b: tuple) -> float:
+    return math.sqrt((a[0] - b[0]) ** 2 + (a[1] - b[1]) ** 2 + (a[2] - b[2]) ** 2)
+
+
+def _project_to_line_position(
+    pt: tuple, offset_dir: tuple, target: float
+) -> tuple[float, float, float]:
+    """Shift *pt* along *offset_dir* so its projection onto that axis equals *target*.
+
+    Keeps every other component of the point unchanged, so only the dimension line
+    is repositioned — the measured length stays the same.
+    """
+    current = pt[0] * offset_dir[0] + pt[1] * offset_dir[1] + pt[2] * offset_dir[2]
+    delta = target - current
+    return (
+        pt[0] + delta * offset_dir[0],
+        pt[1] + delta * offset_dir[1],
+        pt[2] + delta * offset_dir[2],
+    )
+
+
+def _get_anchor_face_normal_world(
+    file: ifcopenshell.file,
+    anchor: dict,
+    placement_override: Optional[dict] = None,
+) -> Optional[tuple[float, float, float]]:
+    """Return the world-space unit face normal stored in a FACE anchor, or None.
+
+    Reads ``normal_local`` (element-local, rotation-invariant) from the anchor
+    addr and rotates it to world space via the current element placement.
+    Also accepts the legacy ``addr.fingerprint.normal_local`` format.
+    """
+    if anchor.get("type") != "FACE":
+        return None
+    guid = anchor.get("guid")
+    if not guid:
+        return None
+    try:
+        element = file.by_guid(guid)
+    except Exception:
+        return None
+
+    addr = anchor.get("addr") or {}
+    from .resolve_anchor import _rotate_local_to_world
+
+    if addr.get("method") == "LAYER_BOUNDARY":
+        import ifcopenshell.util.element as _ifc_elem
+        usage = _ifc_elem.get_material(element, should_inherit=True)
+        if not usage or not usage.is_a("IfcMaterialLayerSetUsage"):
+            return None
+        axis = (getattr(usage, "LayerSetDirection", None) or "AXIS2")
+        if axis == "AXIS1":
+            normal_local: tuple = (1.0, 0.0, 0.0)
+        elif axis == "AXIS3":
+            normal_local = (0.0, 0.0, 1.0)
+        else:
+            normal_local = (0.0, 1.0, 0.0)
+    else:
+        # FACE_NORMAL: normal_local stored in addr (new) or addr.fingerprint (legacy).
+        normal_local = addr.get("normal_local") or (addr.get("fingerprint") or {}).get("normal_local")
+        if not normal_local:
+            return None
+
+    n = _rotate_local_to_world(element, normal_local, placement_override)
+    mag = math.sqrt(n[0] ** 2 + n[1] ** 2 + n[2] ** 2)
+    return (n[0] / mag, n[1] / mag, n[2] / mag) if mag > 1e-12 else None
+
+
+def _get_line_offset_direction(
+    face_normal: Optional[tuple[float, float, float]],
+    resolved_pts: list[tuple],
+) -> Optional[tuple[float, float, float]]:
+    """Return the direction to apply LineOffset — parallel to the first face.
+
+    Uses cross(world_Z, dim_direction) to get the horizontal direction
+    perpendicular to the dimension line, which slides the line sideways
+    (parallel to the face) rather than into/out of it.
+
+    Falls back to cross(face_normal, world_Z) when the dimension line is
+    nearly vertical (e.g. elevation dimensions).
+    """
+    world_z = (0.0, 0.0, 1.0)
+
+    # Primary: use the dimension line direction (anchor[0] → anchor[1])
+    if len(resolved_pts) >= 2:
+        a, b = resolved_pts[0], resolved_pts[1]
+        dx, dy, dz = b[0] - a[0], b[1] - a[1], b[2] - a[2]
+        dim_mag = math.sqrt(dx * dx + dy * dy + dz * dz)
+        if dim_mag > 1e-10:
+            dim_dir = (dx / dim_mag, dy / dim_mag, dz / dim_mag)
+            # cross(world_Z, dim_dir) — horizontal direction perp to dimension
+            d = (
+                world_z[1] * dim_dir[2] - world_z[2] * dim_dir[1],
+                world_z[2] * dim_dir[0] - world_z[0] * dim_dir[2],
+                world_z[0] * dim_dir[1] - world_z[1] * dim_dir[0],
+            )
+            mag = math.sqrt(d[0] ** 2 + d[1] ** 2 + d[2] ** 2)
+            if mag > 1e-6:
+                return (d[0] / mag, d[1] / mag, d[2] / mag)
+
+    # Fallback for vertical dims: cross(face_normal, world_Z)
+    if face_normal:
+        n = face_normal
+        d = (
+            n[1] * world_z[2] - n[2] * world_z[1],
+            n[2] * world_z[0] - n[0] * world_z[2],
+            n[0] * world_z[1] - n[1] * world_z[0],
+        )
+        mag = math.sqrt(d[0] ** 2 + d[1] ** 2 + d[2] ** 2)
+        if mag > 1e-6:
+            return (d[0] / mag, d[1] / mag, d[2] / mag)
+
+    return None

src/ifcopenshell-python/ifcopenshell/draw.py

@@ -42,7 +42,8 @@ WHITE = numpy.array((1.0, 1.0, 1.0))
 
 DO_NOTHING = lambda *args: None
 
-ARRANGE_POLYGON_SETTINGS = W.arrange_polygon_settings() if hasattr(W, 'arrange_polygon_settings') else None
+ARRANGE_POLYGON_SETTINGS = W.arrange_polygon_settings() if hasattr(W, "arrange_polygon_settings") else None
+
 
 @dataclass
 class draw_settings:

src/ifcopenshell-python/ifcopenshell/express/schema_class.py

@@ -420,7 +420,15 @@ class SchemaClass(codegen.Base):
 
             if isinstance(type, nodes.AggregationType):
                 aggr_type = type.aggregate_type
-                make_bound = lambda b: -1 if b == "?" else int(b)
+
+                def make_bound(b):
+                    # `?` and non-literal bounds (attribute references, arithmetic expressions) collapse to -1.
+                    #
+                    try:
+                        return int(b)
+                    except (TypeError, ValueError):
+                        return -1
+
                 bound1, bound2 = map(make_bound, (type.bounds.lower, type.bounds.upper))
                 decl_type = get_declared_type(type.type, emitted_names)
                 return x.aggregation_type(aggr_type, bound1, bound2, decl_type)
@@ -547,7 +555,16 @@ class SchemaClass(codegen.Base):
                 inv_attrs = []
                 for attr in type.inverse:
                     if attr.bounds:
-                        make_bound = lambda b: -1 if b == "?" else int(b)
+
+                        def make_bound(b):
+                            # `?` and non-literal bounds (attribute references, arithmetic
+                            # expressions) collapse to -1 (unbounded) — the C++ runtime has
+                            # no third state for "dynamic cardinality".
+                            try:
+                                return int(b)
+                            except (TypeError, ValueError):
+                                return -1
+
                         bound1, bound2 = map(make_bound, (attr.bounds.lower, attr.bounds.upper))
                     else:
                         bound1, bound2 = -1, -1

src/ifcopenshell-python/ifcopenshell/util/cost.py

@@ -196,9 +196,12 @@ def get_cost_items_for_product(product: ifcopenshell.entity_instance) -> list[if
     :return: A list of IfcCostItem objects representing the cost items related to the product.
     """
     cost_items = []
-    for assignment in product.HasAssignments:
-        if assignment.is_a("IfcRelAssignsToControl") and assignment.RelatingControl.is_a("IfcCostItem"):
-            cost_items.append(assignment.RelatingControl)
+    for assignment in product.HasAssignments or []:
+        if assignment.is_a("IfcRelAssignsToControl"):
+            control = assignment.RelatingControl
+            if control and control.is_a("IfcCostItem"):
+                cost_items.append(control)
+
     return cost_items
 
 

src/ifcopenshell-python/test/test_express_aggregate_bounds.py

@@ -0,0 +1,74 @@
+import os
+import sys
+import tempfile
+import unittest
+
+import ifcopenshell.express
+
+sys.path.insert(0, os.path.dirname(ifcopenshell.express.__file__))
+
+
+def _parse(schema_text):
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".exp", delete=False) as f:
+        f.write(schema_text)
+        path = f.name
+    try:
+        return ifcopenshell.express.parse(path)
+    finally:
+        os.unlink(path)
+        cache = path + ".cache.dat"
+        if os.path.exists(cache):
+            os.unlink(cache)
+
+
+class TestAggregateBounds(unittest.TestCase):
+    def test_literal_bounds_preserved(self):
+        """After loading [1;3] -> (1, 3)?"""
+        s = _parse("SCHEMA t; ENTITY E; v : ARRAY [1:3] OF REAL; END_ENTITY; END_SCHEMA;")
+        agg = (
+            next(d for d in s.schema.declarations() if d.name() == "E")
+            .attributes()[0]
+            .type_of_attribute()
+            .as_aggregation_type()
+        )
+        self.assertEqual((agg.bound1(), agg.bound2()), (1, 3))
+        s.disown()
+
+    def test_unbounded_marker(self):
+        """[0:?] -> (0, -1)?"""
+        s = _parse("SCHEMA t; ENTITY E; v : LIST [0:?] OF REAL; END_ENTITY; END_SCHEMA;")
+        agg = (
+            next(d for d in s.schema.declarations() if d.name() == "E")
+            .attributes()[0]
+            .type_of_attribute()
+            .as_aggregation_type()
+        )
+        # import pdb; pdb.set_trace()
+        self.assertEqual((agg.bound1(), agg.bound2()), (0, -1))
+        s.disown()
+
+    def test_voxel_grid_with_dynamic_bound_loads(self):
+        """
+        Array that is an expression :  [1:dim_x*dim_y*dim_z]
+        Parsing must not crash, Bbund must be (1, -1)
+        """
+        s = _parse("""
+            SCHEMA t;
+            TYPE IfcBoolean = BOOLEAN; END_TYPE;
+
+            ENTITY IfcVoxelHolder;
+              NumberOfVoxelsX : INTEGER;
+              NumberOfVoxelsY : INTEGER;
+              NumberOfVoxelsZ : INTEGER;
+              Voxels : ARRAY [1:NumberOfVoxelsX*NumberOfVoxelsY*NumberOfVoxelsZ] OF IfcBoolean;
+            END_ENTITY;
+            END_SCHEMA;
+            """)
+        holder = next(d for d in s.schema.declarations() if d.name() == "IfcVoxelHolder")
+        voxels = holder.attributes()[-1].type_of_attribute().as_aggregation_type()
+        self.assertEqual((voxels.bound1(), voxels.bound2()), (1, -1))
+        s.disown()
+
+
+if __name__ == "__main__":
+    unittest.main()

src/ifcopenshell-python/test/util/test_cost.py

@@ -0,0 +1,52 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell 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 Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import pytest
+
+import ifcopenshell.api.control
+import ifcopenshell.api.cost
+import test.bootstrap
+import ifcopenshell.api.root
+
+import ifcopenshell.util.cost as subject
+
+class TestGetCostItemForProduct(test.bootstrap.IFC4):
+    def test_run(self):
+        model = self.file
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        cost_schedule = ifcopenshell.api.cost.add_cost_schedule(model)
+        item1 = ifcopenshell.api.cost.add_cost_item(model, cost_schedule=cost_schedule)
+        ifcopenshell.api.control.assign_control(model, related_objects=[element], relating_control=item1)
+        assert list(subject.get_cost_items_for_product(element)) == [item1]
+
+    def test_remove_cost_item(self):
+        model = self.file
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        cost_schedule = ifcopenshell.api.cost.add_cost_schedule(model)
+        item1 = ifcopenshell.api.cost.add_cost_item(model, cost_schedule=cost_schedule)
+        ifcopenshell.api.control.assign_control(model, related_objects=[element], relating_control=item1)
+        ifcopenshell.api.cost.remove_cost_item(model, cost_item = item1)
+        assert list(subject.get_cost_items_for_product(element)) == []
+
+    def test_no_assigned_cost_items(self):
+        model = self.file
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        cost_schedule = ifcopenshell.api.cost.add_cost_schedule(model)
+        item1 = ifcopenshell.api.cost.add_cost_item(model, cost_schedule=cost_schedule)
+        assert list(subject.get_cost_items_for_product(element)) == []
+

src/ifcparse/IfcHierarchyHelper.h

@@ -475,7 +475,7 @@ class IFC_PARSE_API IfcHierarchyHelper : public IfcParse::IfcFile {
                 t->set_attribute_value(1, owner_hist);
                 int relating_index = 4;
                 int related_index = 5;
-                if (T::Class().name() == "IfcRelContainedInSpatialStructure" || std::is_base_of<typename Schema::IfcRelDefines, T>::value) {
+                if (T::Class().name() == "IfcRelContainedInSpatialStructure" || T::Class().name() == "IfcRelReferencedInSpatialStructure" || std::is_base_of<typename Schema::IfcRelDefines, T>::value) {
                     // some classes have attributes reversed.
                     std::swap(relating_index, related_index);
                 }

src/svgfill/src/arrange_polygons.cpp

@@ -432,6 +432,15 @@ class DebugWriter {
         }
     }
 
+    void write_point(const Point_2& p, const std::string& name) {
+        if (enabled_) {
+            obj << "o " << name << "\n";
+            obj << "v " << CGAL::to_double(p.x()) << " " << CGAL::to_double(p.y()) << " 0\n";
+            vi++;
+            svg << "<circle class=\"" << name << "\" cx=\"" << CGAL::to_double(p.x()) << "\" cy=\"" << -CGAL::to_double(p.y()) << "\" r=\"0.5\" />\n";
+        }
+    }
+
     void write_polygon(const Polygon_with_holes_2& polygon, const std::string& name) {
         if (enabled_) {
             write_polygon(polygon.outer_boundary(), name);
@@ -452,6 +461,20 @@ class DebugWriter {
         }
     }
 
+    void write_polygons(const Arrangement_2& arr, const std::string& name) {
+        if (enabled_) {
+            // Just for the automatic numbering, create a full vector
+            std::vector<Polygon_2> temp;
+            for (auto it = arr.faces_begin(); it != arr.faces_end(); ++it) {
+                if (it->is_unbounded()) {
+                    continue;
+                }
+                temp.push_back(circ_to_poly(it->outer_ccb()));
+            }
+            write_polygons(temp, name);
+        }
+    }
+
     void write_polygons(const std::vector<Polygon_with_holes_2>& polygons, const std::string& name) {
         if (enabled_) {
             size_t i = 0;
@@ -475,7 +498,14 @@ class DebugWriter {
     std::string last_segment_name_;
     
     void write_polygon_to_svg_(std::ostream& ofs, const Polygon_2& polygon, const std::string& class_name = "") {
-        ofs << "<polygon class=\"" + class_name + "\" points=\"";
+        auto class_name_ = class_name;
+        if (!polygon.is_simple()) {
+            if (!class_name_.empty()) {
+                class_name_ += " ";
+            }
+            class_name_ += "self_intersecting";
+        }
+        ofs << "<polygon class=\"" + class_name_ + "\" points=\"";
         for (auto vit = polygon.vertices_begin(); vit != polygon.vertices_end(); ++vit) {
             ofs << CGAL::to_double(vit->x()) << "," << -CGAL::to_double(vit->y()) << " ";
         }
@@ -804,6 +834,10 @@ class SegmentLookup {
         return out;
     }
 
+    PolygonIt end() const {
+        return polygons_ref_.end();
+    }
+
 private:
     using TreeTraits = CGAL::AABB_traits<K, CGAL::AABB_segment_primitive<K, std::list<CGAL::Segment_3<K>>::iterator>>;
     using Tree = CGAL::AABB_tree<TreeTraits>;
@@ -816,25 +850,33 @@ private:
     std::map<Point_2, std::vector<Polygon_2>::const_iterator> input_polygon_boundary_cache_;
 };
 
-Polygon_2 subdivide_polygon(double max_distance, const Polygon_2 & p) {
+Polygon_2 subdivide_polygon_on_same_input(SegmentLookup& segment_lookup, double max_distance, const Polygon_2& p, std::map<Point_2, SegmentLookup::PolygonIt>& point_lookup) {
     std::vector<Point_2> points;
     for (auto it = p.edges_begin(); it != p.edges_end(); ++it) {
+        auto source_poly = segment_lookup.input_polygon_boundary(it->source());
+        auto target_poly = segment_lookup.input_polygon_boundary(it->target());
         const auto& seg = *it;
-        auto num_splits = (int)std::ceil(std::sqrt(CGAL::to_double(seg.squared_length())) / max_distance) - 1;
         points.push_back(seg.source());
-        for (auto i = 0; i < num_splits; ++i) {
-            auto d = (seg.target() - seg.source()) / (num_splits + 1) * (i + 1);
-            points.push_back(seg.source() + d);
+        if (source_poly == target_poly && source_poly != segment_lookup.end()) {
+            point_lookup.emplace(seg.source(), source_poly);
+            point_lookup.emplace(seg.target(), source_poly);
+            auto num_splits = (int)std::ceil(std::sqrt(CGAL::to_double(seg.squared_length())) / max_distance) - 1;
+            for (auto i = 0; i < num_splits; ++i) {
+                auto d = (seg.target() - seg.source()) / (num_splits + 1) * (i + 1);
+                auto p = seg.source() + d;
+                point_lookup.emplace(p, source_poly);
+                points.push_back(p);
+            }
         }
     }
     return Polygon_2(points.begin(), points.end());
 };
 
-Polygon_with_holes_2 subdivide_polygon(double max_distance, const Polygon_with_holes_2& pwh) {
-    Polygon_2 outer = subdivide_polygon(max_distance, pwh.outer_boundary());
+Polygon_with_holes_2 subdivide_polygon_on_same_input(SegmentLookup& segment_lookup, double max_distance, const Polygon_with_holes_2& pwh, std::map<Point_2, SegmentLookup::PolygonIt>& point_lookup) {
+    Polygon_2 outer = subdivide_polygon_on_same_input(segment_lookup, max_distance, pwh.outer_boundary(), point_lookup);
     std::vector<Polygon_2> holes;
     for (auto hit = pwh.holes_begin(); hit != pwh.holes_end(); ++hit) {
-        holes.push_back(subdivide_polygon(max_distance, *hit));
+        holes.push_back(subdivide_polygon_on_same_input(segment_lookup, max_distance, *hit, point_lookup));
     }
     return Polygon_with_holes_2(outer, holes.begin(), holes.end());
 };
@@ -845,7 +887,7 @@ std::tuple<
     std::map<std::pair<Point_2, Point_2>, std::vector<const CGAL::Polygon_2<K>*>>,
     std::map<Point_2, double>
 >
-build_line_graph(const std::vector<Polygon_2>& input_polygons, SegmentLookup& segment_lookup, const std::vector<Polygon_2>& triangular_polygons)
+build_line_graph(const std::vector<Polygon_2>& input_polygons, const std::map<Point_2, SegmentLookup::PolygonIt>& point_lookup, const std::vector<Polygon_2>& triangular_polygons)
 {
 
     // Build maps of triangle -> edge and edge -> triangle in order to do traversal on the 'corridor mesh'
@@ -874,13 +916,17 @@ build_line_graph(const std::vector<Polygon_2>& input_polygons, SegmentLookup& se
     for (auto& p : segment_to_facet) {
         auto center = CGAL::ORIGIN + (((p.first.first - CGAL::ORIGIN) + (p.first.second - CGAL::ORIGIN)) / 2);
 
-        auto p1index = segment_lookup.input_polygon_boundary(p.first.first);
-        auto p2index = segment_lookup.input_polygon_boundary(p.first.second);
+        auto p1index = point_lookup.find(p.first.first);
+        auto p2index = point_lookup.find(p.first.second);
 
-        segment_to_input_facet[p.first].push_back(&*p1index);
-        segment_to_input_facet[p.first].push_back(&*p2index);
+        if (p1index == point_lookup.end() || p2index == point_lookup.end()) {
+            continue;
+        }
 
-        if (p1index != input_polygons.end() && p2index != input_polygons.end() && p1index != p2index) {
+        segment_to_input_facet[p.first].push_back(&*p1index->second);
+        segment_to_input_facet[p.first].push_back(&*p2index->second);
+
+        if (p1index->second != input_polygons.end() && p2index->second != input_polygons.end() && p1index->second != p2index->second) {
             segment_to_midpoint[p.first] = center;
             midpoint_to_segment[center] = p.first;
             midpoint_to_edge_length[center] = std::sqrt(CGAL::to_double(CGAL::squared_distance(p.first.first, p.first.second)));
@@ -1039,6 +1085,45 @@ bool aabb_overlap(const DBox& a, const DBox& b, double eps = 1.e-9) {
            a[1].y() + eps >= b[0].y();
 }
 
+std::pair<double, double> projected_interval_on_axis(const std::array<DPoint, 4>& points, const DDir& axis_u) {
+    auto u = unit(axis_u);
+    auto t0 = (points.front() - CGAL::ORIGIN) * u;
+    auto interval = std::make_pair(t0, t0);
+    for (auto& p : points) {
+        auto t = (p - CGAL::ORIGIN) * u;
+        interval.first = std::min(interval.first, t);
+        interval.second = std::max(interval.second, t);
+    }
+    return interval;
+}
+
+bool intervals_overlap(const std::pair<double, double>& a, const std::pair<double, double>& b, double eps = 1.e-9) {
+    return a.first <= b.second + eps && b.first <= a.second + eps;
+}
+
+bool obb_overlap(const std::array<DPoint, 4>& a, const std::array<DPoint, 4>& b, double eps = 1.e-9) {
+    auto has_separating_axis = [&](const std::array<DPoint, 4>& points) {
+        for (size_t i = 0; i < points.size(); ++i) {
+            auto edge = points[(i + 1) % points.size()] - points[i];
+            auto axis = unit(perpendicular(edge));
+            if (axis.squared_length() < 1.e-18) {
+                continue;
+            }
+            if (!intervals_overlap(projected_interval_on_axis(a, axis), projected_interval_on_axis(b, axis), eps)) {
+                return true;
+            }
+        }
+        return false;
+    };
+
+    return !has_separating_axis(a) && !has_separating_axis(b);
+}
+
+template <typename T, typename U>
+bool obb_overlap(const T& a, const U& b, double eps = 1.e-9) {
+    return obb_overlap(a.corners, b.corners, eps);
+}
+
 CenterLineGraphData make_center_line_graph_data(
     const std::map<Point_2, std::vector<Point_2>>& line_graph,
     const std::map<Point_2, double>& midpoint_to_edge_length)
@@ -1332,6 +1417,9 @@ bool clusters_can_merge(const BoxCluster& a, const BoxCluster& b, double angle_t
     if (!aabb_overlap(a.box.bbox, b.box.bbox)) {
         return false;
     }
+    if (!obb_overlap(a.box, b.box)) {
+        return false;
+    }
     if (angle_between_dirs_deg(a.box.direction, b.box.direction) > angle_tol_deg) {
         return false;
     }
@@ -1461,8 +1549,8 @@ double point_to_oriented_box_distance(const DPoint& p, const MergedBoxRecord& bo
 
 std::map<Point_2, std::vector<Point_2>> snap_points_to_box_axes(
     const CenterLineGraphData& graph,
-    const std::vector<MergedBoxRecord>& boxes)
-{
+    const std::vector<MergedBoxRecord>& boxes,
+    const K::FT& max_projection_distance) {
     std::vector<Point_2> snapped_points(graph.points.size());
 
     for (size_t i = 0; i < graph.points.size(); ++i) {
@@ -1521,7 +1609,13 @@ std::map<Point_2, std::vector<Point_2>> snap_points_to_box_axes(
             }
             return a.line_distance < b.line_distance;
         });
-        snapped_points[i] = best.projection;
+
+        if ((graph.points[i] - best.projection).squared_length() < (max_projection_distance * max_projection_distance)) {
+            snapped_points[i] = best.projection;
+        } else {
+            snapped_points[i] = graph.points[i];
+            std::cout << "Warning: snapping distance exceeding distance: " << std::sqrt(CGAL::to_double((snapped_points[i] - best.projection).squared_length())) << " > " << max_projection_distance << std::endl;
+        }
     }
 
     std::map<Point_2, std::set<Point_2>> adjacency;
@@ -1545,8 +1639,8 @@ std::map<Point_2, std::vector<Point_2>> snap_points_to_box_axes(
 Graph2D<K> join_segment_runs(
     DebugWriter& debug,
     const std::map<Point_2, std::vector<Point_2>>& line_graph,
-    const std::map<Point_2, double>& midpoint_to_edge_length)
-{
+    const std::map<Point_2, double>& midpoint_to_edge_length,
+    const K::FT& max_projection_distance) {
     auto graph = make_center_line_graph_data(line_graph, midpoint_to_edge_length);
     auto runs = runs_from_graph(graph);
     runs.erase(std::remove_if(runs.begin(), runs.end(), [](const LineRun& run) {
@@ -1577,7 +1671,7 @@ Graph2D<K> join_segment_runs(
     }
     debug.write_polygons(run_polygons, "merged_boxes");
 
-    auto snapped_graph = snap_points_to_box_axes(graph, boxes);
+    auto snapped_graph = snap_points_to_box_axes(graph, boxes, max_projection_distance);
     return Graph2D<K>(snapped_graph);
 }
 
@@ -2069,6 +2163,104 @@ std::list<std::pair<Point_2, Point_2>> extend_end_vertices_based_on_input(
     return constructed_segments;
 }
 
+std::list<std::pair<Point_2, Point_2>>
+extend_end_vertices_based_on_input_simple(
+    const Graph2D<K>& G,
+    const Polygon_list& outer_perimiter,
+    const K::FT& max_projection_distance)
+{
+    auto max_intersection_distance = max_projection_distance / 4;
+    std::list<std::pair<Point_2, Point_2>> constructed_segments;
+
+        for (auto it = G.vertices_begin(); it != G.vertices_end(); ++it) {
+        if (it->second.size() == 1) {
+            auto& M = it->first;
+
+            for (auto& bnd : outer_perimiter) {
+                // if point M is contained in bnd interior:
+                // if (!bnd.has_on_unbounded_side(M)) {
+                if (bnd.has_on_bounded_side(M)) {
+                    auto& incoming = *it->second.begin();
+                    // create ray incoming -> M
+                    CGAL::Ray_2<K> ray(incoming, M - incoming);
+
+                    // intersect ray with boundary
+                    boost::optional<CGAL::Segment_2<K>> closest_segment;
+                    boost::optional<CGAL::Point_2<K>> closest_intersection_point;
+                    K::FT sq_distance_along_ray = std::numeric_limits<double>::infinity();
+                    for (auto jt = bnd.edges_begin(); jt != bnd.edges_end(); ++jt) {
+                        const auto& seg = *jt;
+                        auto x = CGAL::intersection(ray, seg);
+                        if (x) {
+                            if (auto* xp = variant_get<CGAL::Point_2<K>>(&*x)) {
+                                auto dist = ((*xp) - M).squared_length();
+                                if (dist < sq_distance_along_ray) {
+                                    if (dist < (max_intersection_distance * max_intersection_distance)) {
+                                        closest_segment = seg;
+                                        closest_intersection_point = *xp;
+                                        sq_distance_along_ray = dist;
+                                    } else {
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    if (closest_intersection_point) {
+                        constructed_segments.push_front({M, *closest_intersection_point});
+                    } else {
+
+                        // Loop over boundary segments, and project point onto it, take the closest
+                        K::FT closest_distance = std::numeric_limits<double>::infinity();
+                        boost::optional<CGAL::Point_2<K>> closest_point;
+                        for (auto& poly : outer_perimiter) {
+                            for (auto jt = poly.edges_begin(); jt != poly.edges_end(); ++jt) {
+                                auto seg = *jt;
+                                auto Pp = seg.supporting_line().projection(M);
+                                if (seg.has_on(Pp)) {
+                                    auto d = CGAL::squared_distance(Pp, M);
+                                    if (d < (max_projection_distance * max_projection_distance)) {
+                                        if (d < closest_distance) {
+                                            closest_distance = d;
+                                            closest_point = Pp;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+
+                        if (closest_point) {
+                            constructed_segments.push_front({M, *closest_point});
+                        } else {
+
+                            for (auto& poly : outer_perimiter) {
+                                for (auto it = poly.begin(); it != poly.end(); ++it) {
+                                    auto Pp = *it;
+                                    auto d = CGAL::squared_distance(Pp, M);
+                                    if (d < (max_projection_distance * max_projection_distance)) {
+                                        if (d < closest_distance) {
+                                            closest_distance = d;
+                                            closest_point = Pp;
+                                        }
+                                    }
+                                }
+                            }
+
+                            if (closest_point) {
+                                constructed_segments.push_front({M, *closest_point});
+                            } else {
+                                std::cout << "Unable to find projection or intersection point for interior boundary (" << M.x() << " " << M.y() << ")" << std::endl;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    return constructed_segments;
+}
+
 void fuse_corridor_halves_with_input(Arrangement_2& arr, Graph2D<K>& G, SegmentLookup& segment_lookup, const Polygon_list& input_polygons, DebugWriter& debug_output) {
     std::set<Arrangement_2::Halfedge_handle> edges_to_remove;
 
@@ -2161,7 +2353,7 @@ class Segment_2_less {
     }
 };
 
-std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& right) {
+std::vector<K::FT> arrangement_cell_iou(DebugWriter& debug_output, Arrangement_2& left, Arrangement_2& right) {
 
     using Walk_pl = CGAL::Arr_walk_along_line_point_location<Arrangement_2>;
     Walk_pl walk_pl(right);
@@ -2170,6 +2362,9 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
 
     std::vector<K::FT> return_values;
 
+    K::FT max_iou_deviation = 1;
+    std::array<Polygon_2, 2> max_deviation_poly_pair;
+
     for (auto it = left.faces_begin(); it != left.faces_end(); ++it) {
         if (!it->is_unbounded()) {
             // convert arr facet to polygon with holes
@@ -2178,6 +2373,9 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
             for (auto hit = it->inner_ccbs_begin(); hit != it->inner_ccbs_end(); ++hit) {
                 pwh.add_hole(circ_to_poly(*hit));
             }
+            // if (!pwh.outer_boundary().is_simple()) {
+            //     throw std::runtime_error("Polygon with holes has a non-simple outer boundary");
+            // }
 
             CGAL::Polygon_triangulation_decomposition_2<K> decompositor;
             std::vector<Polygon_2> temp;
@@ -2218,10 +2416,26 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
                     }
                 }
 
+                if (max_score == -std::numeric_limits<double>::infinity()) {
+                    // no more points to try
+                    return_values.push_back(0);
+                    break;
+                }
+
+                visited_points.insert(best_point);
+
+                debug_output.write_point(best_point, "representative_point representative_point_" + std::to_string(std::distance(left.faces_begin(), it)));
+
                 auto res = walk_pl.locate(best_point);
                 if (auto* v = variant_get<Arrangement_2::Face_const_handle>(&res)) {
+                    if ((*v)->is_unbounded()) {
+                        // try next point
+                        continue;
+                    }
                     if (visited_faces_on_right.count(*v) > 0) {
+                        // Maybe we should be more permissive, try some other points etc.
                         return_values.push_back(0);
+                        std::cout << "Already visited face on right, skipping point\n";
                     } else {
                         // convert arr facet to polygon with holes
                         auto polygon_exterior = circ_to_poly((*v)->outer_ccb());
@@ -2229,6 +2443,9 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
                         for (auto hit = (*v)->inner_ccbs_begin(); hit != (*v)->inner_ccbs_end(); ++hit) {
                             pwh_right.add_hole(circ_to_poly(*hit));
                         }
+                        // if (!pwh_right.outer_boundary().is_simple()) {
+                        //     throw std::runtime_error("Polygon with holes has a non-simple outer boundary");
+                        // }
 
                         // compute intersection over union of pwh and the original polygon
                         if (CGAL::do_intersect(pwh, pwh_right)) {
@@ -2238,7 +2455,7 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
                             for (auto& r : result) {
                                 auto poly_area = r.outer_boundary().area();
                                 for (auto& h : r.holes()) {
-                                    poly_area -= h.area();
+                                    poly_area -= CGAL::abs(h.area());
                                 }
                                 intersection_area += poly_area;
                             }
@@ -2246,10 +2463,17 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
                             CGAL::join(pwh, pwh_right, poly12);
                             typename K::FT union_area = poly12.outer_boundary().area();
                             for (auto& h : poly12.holes()) {
-                                union_area -= h.area();
+                                union_area -= CGAL::abs(h.area());
                             }
                             return_values.push_back(intersection_area / union_area);
+
+                            auto& v = return_values.back();
+                            if (v < max_iou_deviation) {
+                                max_iou_deviation = v;
+                                max_deviation_poly_pair = {pwh.outer_boundary(), pwh_right.outer_boundary()};
+                            }
                         } else {
+                            std::cout << "No intersection, skipping point\n";
                             return_values.push_back(0);
                         }
                     }
@@ -2263,6 +2487,11 @@ std::vector<K::FT> arrangement_cell_iou(Arrangement_2& left, Arrangement_2& righ
         }
     }
 
+    if (max_iou_deviation != 1) {
+        debug_output.write_polygon(max_deviation_poly_pair[0], "max_iou_deviation_left");
+        debug_output.write_polygon(max_deviation_poly_pair[1], "max_iou_deviation_right");
+    }
+
     return return_values;
 }
 
@@ -2935,7 +3164,20 @@ class timer {
     bool enabled_;
 };
 
+size_t delete_same_facet_edge_pairs(Arrangement_2& arr) {
+    size_t n_deleted = 0;
+    for (auto it = arr.edges_begin(); it != arr.edges_end();) {
+        decltype(it) current = it++;
+        if (current->face() == current->twin()->face()) {
+            arr.remove_edge(current);
+            n_deleted++;
+        }
+    }
+    return n_deleted;
+}
+
 void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std::vector<Polygon_2>& input_polygons_, std::vector<Polygon_2>& output_polygons, double polygon_offset_distance = -1.) {
+
     static const double OVERLAP_RESOLUTION_DISTANCE = 1.e-1;
     // even larger amount of inset so that outer perimeter is safely within all input polygons even when overlap resolution is applied
     // no, `1.e-2 + 1.e-5` creates issues with the outer perimeter, are there other tolerances in play?
@@ -3097,13 +3339,17 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
     t0.stop();
     t0 = timer.start("corridor triangulation");
 
+    SegmentLookup segment_lookup(input_polygons);
+
     // subdivide difference_result to have better more detailed triangulation and therefore less-pronounced artefacts in midpoint network
 
+    // We store correspondence of subdivision points to input polygons when subdividing so that we do not need to query, which is expensive, when building the line graph later on.
+    std::map<Point_2, SegmentLookup::PolygonIt> point_lookup;
+
     auto subdivision_length = polygon_offset_distance / settings.subdivision_factor;
 
     for (auto& pwh : difference_result) {
-        difference_result_subdivided.push_back(subdivide_polygon(subdivision_length, pwh));
-        // difference_result_subdivided.push_back(subdivide_polygon(polygon_offset_distance / 64., pwh));
+        difference_result_subdivided.push_back(subdivide_polygon_on_same_input(segment_lookup, subdivision_length, pwh, point_lookup));
     }
 
     debug_output.write_polygons(difference_result_subdivided, "corridor_subdivided");
@@ -3128,9 +3374,7 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
 
     debug_output.write_polygons(triangular_polygons, "triangulated_corridor");
 
-    SegmentLookup segment_lookup(input_polygons);
-
-    auto [line_graph, midpoint_to_segment, segment_to_input_facet, midpoint_to_edge_length] = build_line_graph(input_polygons, segment_lookup, triangular_polygons);
+    auto [line_graph, midpoint_to_segment, segment_to_input_facet, midpoint_to_edge_length] = build_line_graph(input_polygons, point_lookup, triangular_polygons);
     for (auto& p : line_graph) {
         for (auto& q : p.second) {
             debug_output.write_segment(p.first, q, "network_1");
@@ -3142,8 +3386,45 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
     t0 = timer.start("center line cleaning");
 
     Graph2D<K> G;
+
+    {
+        // this is applied for both algos
+        auto eliminated_segments = eliminate_triangles(line_graph);
+        for (auto e : eliminated_segments) {
+            debug_output.write_segment(e.first, e.second, "eliminated");
+            for (int i = 0; i < 2; ++i) {
+                auto it = line_graph.find(e.first);
+                if (it == line_graph.end()) {
+                    std::cerr << "Warning: unable to locate vertex for elimination, skipping" << std::endl;
+                    continue;
+                }
+                auto& neighbours = it->second;
+                neighbours.erase(std::remove(neighbours.begin(), neighbours.end(), e.second), neighbours.end());
+                if (neighbours.empty()) {
+                    line_graph.erase(it);
+                }
+                std::swap(e.first, e.second);
+            }
+        }
+    }
+
+    Graph2D<K> G_orig(line_graph);
+
+    auto apply_line_cleaning_algo_1 = [&]() {
+        Graph2D<K> G2(line_graph);
+        G = G2.weld_vertices();
+        for (auto it = G.edges_begin(); it != G.edges_end(); ++it) {
+            debug_output.write_segment(it->first, it->second, "network_2");
+        }
+        eliminate_colinear_vertices(G);
+        edge_slide(G);
+        for (auto it = G.edges_begin(); it != G.edges_end(); ++it) {
+            debug_output.write_segment(it->first, it->second, "network_3");
+        }
+    };
+
     if (settings.line_cleaning_algo == 0) {
-        G = join_segment_runs(debug_output, line_graph, midpoint_to_edge_length);
+        G = join_segment_runs(debug_output, line_graph, midpoint_to_edge_length, subdivision_length * 4);
         Arrangement_2 arr;
         G.to_arrangement(arr);
         Graph2D<K> G2;
@@ -3154,34 +3435,78 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
             debug_output.write_segment(it->first, it->second, "network_2");
         }
     } else {
-        auto eliminated_segments = eliminate_triangles(line_graph);
-
-        Graph2D<K> G2(line_graph);
-        for (auto& e : eliminated_segments) {
-            debug_output.write_segment(e.first, e.second, "eliminated");
-            G2.remove_edge(e.first, e.second);
-        }
-
-        G = G2.weld_vertices();
-
-        for (auto it = G.edges_begin(); it != G.edges_end(); ++it) {
-            debug_output.write_segment(it->first, it->second, "network_2");
-        }
-
-        eliminate_colinear_vertices(G);
-
-        edge_slide(G);
-
-        for (auto it = G.edges_begin(); it != G.edges_end(); ++it) {
-            debug_output.write_segment(it->first, it->second, "network_3");
-        }
+        apply_line_cleaning_algo_1();
     }
 
     t0.stop();
 
     t0 = timer.start("topology");
 
-    auto segments = extend_end_vertices_based_on_input(G, midpoint_to_segment, segment_to_input_facet, outer_perimiter, segment_lookup, subdivision_length * 4);
+    std::list<std::pair<Point_2, Point_2>> segments, segments1, segments2;
+    bool fallback_to_line_cleaning_algo_1 = false;
+    
+    if (settings.line_cleaning_algo == 0) {
+        segments1 = extend_end_vertices_based_on_input_simple(G, outer_perimiter, subdivision_length * 16);
+        segments2 = extend_end_vertices_based_on_input_simple(G_orig, outer_perimiter, subdivision_length * 16);
+        
+        Arrangement_2 arr_clean;
+        G.to_arrangement(arr_clean);
+        for (auto& pq : segments1) {
+            if (pq.first == pq.second) {
+                continue;
+            }
+            CGAL::insert(arr_clean, Segment_2(pq.first, pq.second));
+        }
+
+        Arrangement_2 arr_orig;
+        G_orig.to_arrangement(arr_orig);
+        for (auto& pq : segments2) {
+            if (pq.first == pq.second) {
+                continue;
+            }
+            CGAL::insert(arr_orig, Segment_2(pq.first, pq.second));
+        }
+
+        for (auto& p : outer_perimiter) {
+            for (auto it = p.edges_begin(); it != p.edges_end(); ++it) {
+                auto source = it->source();
+                auto target = it->target();
+                if (source == target) {
+                    continue;
+                }
+                CGAL::insert(arr_orig, Segment_2(source, target));
+                CGAL::insert(arr_clean, Segment_2(source, target));
+            }
+        }
+
+        delete_same_facet_edge_pairs(arr_clean);
+        delete_same_facet_edge_pairs(arr_orig);
+
+        debug_output.write_polygons(arr_clean, "iou_left");
+        debug_output.write_polygons(arr_orig, "iou_right");
+
+        auto ious = arrangement_cell_iou(debug_output, arr_clean, arr_orig);
+        /*
+        for (auto& iou : ious) {
+            std::cout << " " << CGAL::to_double(iou - 1);
+        }
+        std::cout << std::endl;
+        */
+
+        auto it = std::min_element(ious.begin(), ious.end());
+
+        if (it != ious.end() && (*it < 0.45)) {
+            std::cerr << "Significant difference between cleaned and original arrangement, using original for topology reconstruction: " << *it << std::endl;
+            fallback_to_line_cleaning_algo_1 = true;
+            apply_line_cleaning_algo_1();
+        } else {
+            segments = segments1;
+        }
+    }
+
+    if (settings.line_cleaning_algo != 0 || fallback_to_line_cleaning_algo_1) {
+        segments = extend_end_vertices_based_on_input(G, midpoint_to_segment, segment_to_input_facet, outer_perimiter, segment_lookup, subdivision_length * 4);
+    }   
 
     // Now plot the edges on an arrangement in order to find planar cycles
     // and merge the corridor-halves with their neighbouring input polygon
@@ -3223,15 +3548,7 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
         }
     }
 
-    // Just for the automatic numbering, create a full vector
-    std::vector<Polygon_2> temp;
-    for (auto it = arr.faces_begin(); it != arr.faces_end(); ++it) {
-        if (it->is_unbounded()) {
-            continue;
-        }
-        temp.push_back(circ_to_poly(it->outer_ccb()));
-    }
-    debug_output.write_polygons(temp, "arr_faces");
+    debug_output.write_polygons(arr, "arr_faces");
 
 
     /* {
@@ -3256,7 +3573,7 @@ void arrange_cgal_polygons(svgfill::arrange_polygon_settings settings, const std
         double threshold;
         clean_noisy_paths(debug_output, arr, segment_lookup, threshold);
         remove_colinear_vertices(arr);
-        clean_noisy_bounds(debug_output, arr, segment_lookup, threshold);
+        // clean_noisy_bounds(debug_output, arr, segment_lookup, threshold);
     }
 
     t0.stop();

src/svgfill/src/graph_2d.h

@@ -178,6 +178,9 @@ public:
         std::vector<CGAL::Segment_2<Kernel>> segments;
         for (const auto& p : adjacency_list) {
             for (const auto& q : p.second) {
+                if (p.first == q) {
+                    return false;
+                }
                 if (p.first < q) {
                     segments.emplace_back(p.first, q);
                 }
@@ -198,7 +201,7 @@ public:
                 any = true;
             }
         });
-        return any;
+        return !any;
     }
 
     // Eliminates a vertex with exactly two neighbors by connecting its neighbors
@@ -338,12 +341,21 @@ public:
 
     template <typename T>
     void to_arrangement(T& arr) {
-        for (auto it = edges_begin(); it != edges_end(); ++it) {
-            if (it->first == it->second) {
-                continue;
+        if (is_valid() && arr.is_empty()) {
+            std::vector<CGAL::Segment_2<Kernel>> edges;
+            
+            for (auto it = edges_begin(); it != edges_end(); ++it) {
+                edges.emplace_back(it->first, it->second);
             }
-            CGAL::insert(arr, CGAL::Segment_2<Kernel>(it->first, it->second));
-        }
+            CGAL::insert_non_intersecting_curves(arr, edges.begin(), edges.end());
+        } else {
+            for (auto it = edges_begin(); it != edges_end(); ++it) {
+                if (it->first == it->second) {
+                    continue;
+                }
+                CGAL::insert(arr, CGAL::Segment_2<Kernel>(it->first, it->second));
+            }
+        }        
     }
 
     template <typename T>