Project parametric dimensions onto annotation drawing plane

In section/elevation views the resolved anchor points have non-zero depth
relative to the camera, causing dimension curves to float in 3D space instead
of lying flat on the drawing plane. Zero each point's annotation-local Z in
_update_blender_curve so all parametric dimensions land on the same plane as
other annotations regardless of view type. IFC is updated with projected
coords too so Edit Mode reloads stay consistent.

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

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

@@ -8152,6 +8152,20 @@ def _update_blender_curve(
     if not obj or not obj.data or not hasattr(obj.data, "splines"):
         return
 
+    # Parametric dimensions must lie on the annotation object's drawing plane so
+    # they render correctly in section/elevation drawings.  Project every point
+    # by zeroing its annotation-local Z (depth relative to the object origin),
+    # then rebuild world-space coords so both Blender and IFC stay in sync.
+    if ifcopenshell.util.element.get_pset(annotation, "BBIM_Dimension"):
+        inv_world_local = obj.matrix_world.inverted()
+        projected = []
+        for pt in resolved_pts_m:
+            local = inv_world_local @ Vector((float(pt[0]), float(pt[1]), float(pt[2])))
+            local.z = 0.0
+            world = obj.matrix_world @ local
+            projected.append((world.x, world.y, world.z))
+        resolved_pts_m = projected
+
     curve_data: bpy.types.Curve = obj.data
     inv_world = obj.matrix_world.inverted()
     n = len(resolved_pts_m)