Bonsai: draw moved and multi-linked models at their displayed locations

create_drawing opened linked IFCs raw, so a moved link serialized at
its original coordinates and its elements fell outside the drawing.
The stored link transformation is the model-space delta, so it is now
baked into the linework iterator via the model-offset/model-rotation
settings (Trans @ Rot composition matches the rigid matrix
decomposition; the plan-view Z offset adds onto the translation).

The serialization loop also collapsed same-file links into a dict
keyed by filepath, dropping all but the last link. It now iterates one
entry per link and intersects each link's drawing elements with its
selector query, so drawings show what each link displays in the
viewport. Adds tool.Project.get_link_transformation_matrix as the
shared accessor for the stored 4x4.

Verified headless: window link moved +5m appears offset by exactly
5m x scale; unmoved door link at its native position; both present.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

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

@@ -602,7 +602,7 @@ class CreateDrawing(bpy.types.Operator):
         context_type: Literal["body", "annotation"],
         drawing_elements: set[ifcopenshell.entity_instance],
         target_view: str,
-        link_matrix: Optional[Matrix] = None,
+        link_transform: Optional[np.ndarray] = None,
     ) -> None:
         drawing_elements = drawing_elements.copy()
         contexts_: list[list[int]] = getattr(contexts, context_type)
@@ -614,19 +614,22 @@ class CreateDrawing(bpy.types.Operator):
                 geom_settings.set("dimensionality", ifcopenshell.ifcopenshell_wrapper.CURVES_SURFACES_AND_SOLIDS)
                 geom_settings.set("iterator-output", ifcopenshell.ifcopenshell_wrapper.NATIVE)
 
-                is_plan = ifc.by_id(context[0]).ContextType == "Plan" and "PLAN_VIEW" in target_view
-                z_offset = (0.002 if target_view == "PLAN_VIEW" else -0.002) if is_plan else 0.0
-
-                if link_matrix is not None:
-                    unit_scale = ifcopenshell.util.unit.calculate_unit_scale(ifc)
-                    t = link_matrix.to_translation()
-                    offset = (t.x / unit_scale, t.y / unit_scale, t.z / unit_scale + z_offset)
-                    geom_settings.set("model-offset", offset)
-                    q = link_matrix.to_quaternion()
-                    geom_settings.set("model-rotation", (q.x, q.y, q.z, q.w))
-                elif z_offset:
+                offset = np.zeros(3)
+                if ifc.by_id(context[0]).ContextType == "Plan" and "PLAN_VIEW" in target_view:
                     # A 2mm Z offset to combat Z-fighting in plan or RCPs
-                    geom_settings.set("model-offset", (0.0, 0.0, z_offset))
+                    offset[2] = 0.002 if target_view == "PLAN_VIEW" else -0.002
+                if link_transform is not None:
+                    # Bake a moved link's transformation into the geometry. The
+                    # mapping composes Trans(model-offset) @ Rot(model-rotation),
+                    # matching the Trans(t) @ Rot(R) decomposition of the rigid
+                    # link matrix, so the Z offset above simply adds on.
+                    offset += link_transform[:3, 3]
+                    quaternion = Matrix(link_transform.tolist()).to_quaternion()
+                    geom_settings.set(
+                        "model-rotation", (quaternion.x, quaternion.y, quaternion.z, quaternion.w)
+                    )
+                if offset.any():
+                    geom_settings.set("model-offset", tuple(float(o) for o in offset))
 
                 geom_settings.set("context-ids", context)
                 it = ifcopenshell.geom.iterator(
@@ -934,16 +937,24 @@ class CreateDrawing(bpy.types.Operator):
 
         bim_props = tool.Blender.get_bim_props()
         prefs = tool.Blender.get_addon_preferences()
-        # Map ifc_path → (ifc_file, link_matrix); main file has no link_matrix (None)
-        files: dict[str, tuple[ifcopenshell.file, Optional[Matrix]]] = {bim_props.ifc_file: (tool.Ifc.get(), None)}
 
         props = tool.Project.get_project_props()
+        # One entry per file *and* per link - the same file can be linked
+        # several times with different queries and transformations, so links
+        # cannot be collapsed into a dict keyed by filepath.
+        # Each entry is (path, file, link transformation or None, link query).
+        file_entries: list[tuple[str, ifcopenshell.file, Optional[np.ndarray], str]] = [
+            (bim_props.ifc_file, tool.Ifc.get(), None, "")
+        ]
         for link in props.get_loaded_links_for_drawings():
-            try:
-                link_matrix = tool.Project.calculate_link_matrix(link)
-            except Exception:
-                link_matrix = None
-            files[link.filepath] = (self.get_linked_file(link), link_matrix)
+            file_entries.append(
+                (
+                    link.filepath,
+                    self.get_linked_file(link),
+                    tool.Project.get_link_transformation_matrix(link),
+                    link.query,
+                )
+            )
 
         target_view = ifcopenshell.util.element.get_psets(self.camera_element)["EPset_Drawing"]["TargetView"]
         self.setup_serialiser(target_view)
@@ -957,7 +968,7 @@ class CreateDrawing(bpy.types.Operator):
         raycast_objs = set()
         elements_with_faces = set()
 
-        for ifc_path, (ifc, link_matrix) in files.items():
+        for ifc_path, ifc, link_transform, link_query in file_entries:
             # Don't use draw.main() just whilst we're prototyping and experimenting
             # TODO: hash paths are never used
             ifc_hash = hashlib.md5(ifc_path.encode("utf-8")).hexdigest()
@@ -965,6 +976,9 @@ class CreateDrawing(bpy.types.Operator):
 
             self.serialiser.setFile(ifc)
             drawing_elements = tool.Drawing.get_drawing_elements(self.camera_element, ifc_file=ifc)
+            if link_query:
+                # Draw only what the link's selector query loaded in the viewport.
+                drawing_elements &= ifcopenshell.util.selector.filter_elements(ifc, link_query)
 
             if self.cprops.fill_mode == "SHAPELY":
                 for element in drawing_elements.copy():
@@ -980,8 +994,12 @@ class CreateDrawing(bpy.types.Operator):
             # A drawing prioritises a target view context first, followed by a model view context as a fallback.
             # Specifically for PLAN_VIEW and REFLECTED_PLAN_VIEW, any Plan context is also prioritised.
             contexts = self.get_linework_contexts(ifc, target_view)
-            self.serialize_contexts_elements(ifc, tree, contexts, "body", drawing_elements, target_view, link_matrix)
-            self.serialize_contexts_elements(ifc, tree, contexts, "annotation", drawing_elements, target_view, link_matrix)
+            self.serialize_contexts_elements(
+                ifc, tree, contexts, "body", drawing_elements, target_view, link_transform
+            )
+            self.serialize_contexts_elements(
+                ifc, tree, contexts, "annotation", drawing_elements, target_view, link_transform
+            )
 
             if tool.Ifc.get() == ifc and self.camera_element not in drawing_elements:
                 with profile("Camera element"):

src/bonsai/bonsai/tool/project.py

@@ -133,6 +133,20 @@ class Project(bonsai.core.tool.Project):
         local_matrix[:, 3][:3] = [float(o) for o in gprops.model_origin_si.split(",")]
         return Matrix(np.linalg.inv(local_matrix) @ global_matrix)
 
+    @classmethod
+    def get_link_transformation_matrix(cls, link: Link) -> Union[npt.NDArray[np.float64], None]:
+        """Get the link's saved 4x4 transformation in model coordinates, or None when identity."""
+        if tool.Ifc.get():
+            transformation = tool.Ifc.get().by_id(link.ifc_definition_id)[1]  # Identification
+        else:
+            transformation = link.transformation
+        if not transformation:
+            return None
+        matrix = np.fromstring(transformation, sep=",", dtype=np.float64).reshape(4, 4)
+        if np.allclose(matrix, np.eye(4)):
+            return None
+        return matrix
+
     @classmethod
     def calculate_link_delta_matrix(cls, link: Link) -> Matrix:
         """Get the matrix mapping the link's unmoved world positions to its moved ones.