Adds operator to place manual elevation/section drawing reference
tags that survive drawing regeneration. Includes core function,
tool methods, type-selection dialog, default horizontal rotation
for elevation tags, and SVG null guard for unassigned references.

Generated with the assistance of an AI coding tool.

Adds operator to link a manual drawing reference tag to a target
drawing via IfcRelAssignsToProduct, with a pre-populated dialog
and immediate Properties panel refresh on confirm.

Generated with the assistance of an AI coding tool.

Adds MANUAL_DRAWING_REFERENCE to the annotation type dropdown.
Selecting it shows a dialog to choose elevation or section and
optionally assign a target drawing before placement. Tags are
protected from regeneration via EPset_Annotation.IsManualDrawingReference.

Generated with the assistance of an AI coding tool.

The elevation tag's local -Z axis is intentionally parallel to its
drawing camera's view direction, making screen-space projection of that
axis always degenerate (zero XY delta). Fall through to the tag's local
+X axis, which lies in the camera plane and rotates correctly as the
user adjusts the tag's orientation. Also fix a zero-length vector crash
in svgwriter when the same degenerate case occurs during SVG export.

Use get_default_annotation_matrix() for manual SECTION annotations so
the object is placed in the camera's annotation plane with the correct
rotation, matching how auto-generated section annotations are created.
Without this, annotations placed in elevation or section camera views
had identity rotation, causing the IFC representation to be in the wrong
coordinate system and failing to tessellate.

Also guard draw_edit_object_interface against non-IFC active objects to
prevent AssertionError during toolbar redraws, and skip IFC item edit
mode for ELEVATION/SECTION annotation types on placement.

Replace plain enum dropdowns with prop_with_search in the AddAnnotation
and AssignManualDrawingReference operator dialogs, making it easier to
locate a target drawing when many drawings exist in the project.

Generated with the assistance of an AI coding tool.

Extends manual drawing reference annotations (elevation and section) to
also support external SVG references imported via bim.add_reference.

- Add "Is a Reference" checkbox to the annotation tool sidebar, shown
  when Elevation or Section is the active type; checking it and pressing
  Add opens a dialog to optionally link the tag to a Bonsai drawing or
  an external SVG reference
- The MANUAL_DRAWING_REFERENCE dropdown type is retained for backwards
  compatibility; selecting it shows a style picker (Elevation/Section)
  and the same linking dialog
- External-reference annotations are flagged with IsDocumentReference
  in EPset_Annotation and linked to their IfcDocumentInformation via
  IfcRelAssociatesDocument; drawing-reference annotations continue to
  use IfcRelAssignsToProduct as before
- SVG export resolves the correct reference/sheet IDs for both link
  types via get_reference_and_sheet_id_from_annotation
- Add IsDocumentReference to the EPset_Annotation pset template

When a SECTION annotation is created or a drawing is activated,
endpoint vertices are automatically placed at a configurable
BorderOffset (paper-space mm, default 8) inside the camera border,
scaled by the drawing scale. BorderOffset is stored in the
BBIM_Section pset and visible in the Property Sets panel.
An "UpdateSectionEndpoints" operator (bim.update_section_endpoints)
resets endpoints back to the border offset on demand. Endpoints are
also recomputed when the diagram scale is changed.

Generated with the assistance of an AI coding tool.

…BBIM_Dimension.SuppressZeroInches

Generated with the assistance of an AI coding tool.

Generated with the assistance of an AI coding tool.

…eometry

New modal operator (bim.set_dimension_anchor) anchors dimension vertices
to IFC element faces. Anchors are stored as JSON in a BBIM_DimensionTarget
pset on the IfcAnnotation and resolved via tessellation at regeneration time.

- resolve_anchor.py / regenerate_dimension.py: new ifcopenshell API modules
- bim.set_dimension_anchor: 2-phase Object Mode modal (pick vertex → pick face)
- bim.regenerate_dimensions: recomputes all parametric dimensions
- Auto-regeneration via depsgraph_update_post when referenced elements move
- placement_override reads Blender matrix_world for G-moved elements
- Plan-view annotations flattened to annotation plane (Z=0 in local space)
- IfcIndexedPolyCurve.Segments rebuilt to handle n-point chains correctly

…imensions

Extends parametric dimension support with a modal polyline operator that uses
Bonsai's existing snap infrastructure (same as walls/slabs) for placing anchor
points.  Shift+A in the Annotation tool now routes dimension types through this
operator instead of the generic add_annotation path.

- DrawParametricDimension: PolylineOperator subclass; each confirmed snap point
  is converted to a BBIM_DimensionTarget anchor via _snap_to_anchor, which reads
  face_index from the snap dict for face hits and falls back to closest_point_on_mesh
  for vertex/edge hits
- handle_inserting_polyline override tracks anchor list in sync with polyline
  points (insert on count increase, pop on BACKSPACE)
- hotkey_S_A dispatches to bim.draw_parametric_dimension for DIMENSION/RADIUS/
  DIAMETER/ANGLE/PLAN_LEVEL/SECTION_LEVEL types; all other types keep existing path
- depsgraph_update_post_handler extended to also watch is_updated_geometry so
  dimensions auto-regenerate when a referenced mesh is edited in Edit Mode; the
  affected element's tessellation is evicted from _dim_shape_cache so resolve_anchor
  re-tessellates from the updated IFC representation on the next pass

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

SetDimensionAnchor — hover-select-then-confirm:
- Cursor highlights candidate IFC elements (orange Blender selection outline)
  before committing; Tab cycles through overlapping/coplanar candidates
- _compute_candidates: ray-cast all IFC mesh objects; falls back to 2D
  bounding-box proximity (5 cm tolerance) for plan-view picks where the
  ray misses the mesh by sub-mm amounts
- _write_anchor: after anchoring a face, immediately calls
  regenerate_dimension with placement_override (Blender matrix_world)
  and _update_blender_curve so the curve vertex moves to the resolved point

DrawParametricDimension — ForcePerpendicularToFace live snap constraint:
- Reads force_perpendicular_to_face toggle from annotation props on invoke
- After anchor[0] is placed on a FACE, _update_perp_constraint extracts
  the face normal and stores it as the constraint axis
- _apply_perp_constraint runs every modal tick after handle_snap_selection,
  projecting the current snap point onto pt[0] + t*normal
- On finalize, _create_dimension_from_polyline writes ForcePerpendicularToFace
  to the BBIM_Dimension pset and calls regenerate_dimension to snap the
  stored curve to the constraint before the operator exits

regenerate_dimension.py:
- ForcePerpendicularToFace block: after resolving all anchors, projects
  vertices 1…n onto the line through pt[0] along anchor[0]'s face normal
- _get_anchor_face_normal_world: reads normal_local from anchor fingerprint,
  calls _rotate_local_to_world with placement_override; falls back to stored
  world-space normal

resolve_anchor.py:
- _rotate_local_to_world: transforms an element-local direction vector to
  world space using the element's placement or placement_override matrix

pset/operator.py:
- EditPset._execute: after editing a BBIM_Dimension pset on an IfcAnnotation,
  auto-calls regenerate_dimension + _update_blender_curve so changes to
  anchors/ForcePerpendicularToFace are reflected immediately in the viewport

prop.py / workspace.py:
- Added force_perpendicular_to_face BoolProperty to BIMAnnotationProperties
- UI toggle shown in annotation tool header for DIMENSION/RADIUS/DIAMETER/
  ANGLE/PLAN_LEVEL/SECTION_LEVEL types

Psets_BBIM_Annotation.ifc:
- Added ForcePerpendicularToFace property template (#39) to BBIM_Dimension
- Extended BBIM_Dimension applicability to ANGLE, PLAN_LEVEL, SECTION_LEVEL

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

…cularToFace toggle updates selection

workspace.py:
- Move "Set Dimension Anchor" and "Regenerate" buttons from the properties
  panel (ui.py) into draw_edit_object_interface in the annotation tool,
  visible whenever a selected object is a dimension-type IfcAnnotation
- Change force_perpendicular_to_face from a push-button (toggle=True) to
  a standard checkbox for clearer on/off state

ui.py:
- Remove the "Parametric Dimension" section (now lives in the tool header)

prop.py:
- Add _update_force_perpendicular update callback: when the checkbox is
  toggled, iterates all selected dimension annotations, writes the new
  ForcePerpendicularToFace value to each BBIM_Dimension pset, and calls
  regenerate_dimension so the constraint is applied immediately

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

…pendicularToFace

- BBIM_Dimension.LinePosition (IfcLengthMeasure): holds the dimension line at
  a fixed global coordinate along cross(world_Z, dim_direction), independent of
  geometry movement
- regenerate_dimension applies LinePosition only when ForcePerpendicularToFace is
  also set (the two are semantically coupled); anchor["pt"] always stores the true
  surface hit so the measured length is unaffected
- BIMAnnotationProperties.line_position uses get/set callbacks instead of an update
  callback to avoid the 'Writing to ID classes in this context is not allowed' error
  that fires when Blender draws the tool header
- DimensionLinePositionWidget (BIM_GGT_dimension_line_position): gizmo group with
  two opposing GizmoCone handles at the curve midpoint; poll requires
  ForcePerpendicularToFace so the handles only appear when the feature is active
- UI: line_position field and gizmo are hidden when ForcePerpendicularToFace is off
- Psets_BBIM_Annotation.ifc: #40 LinePosition template added to BBIM_Dimension

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

…tric dimensions

- GizmoAnchorHandle + DimensionAnchorWidget: colored dot gizmos at each
  dimension curve vertex (green=anchored, orange=free); color changes to
  blue while SetDimensionAnchor is in PICK_FACE mode for that vertex
- ClickNearestDimensionAnchor (LMB keymap): Python proximity operator that
  fires SetDimensionAnchor pre-targeted at the nearest anchor dot within
  120px, returning PASS_THROUGH for misses so normal viewport clicks are
  unaffected
- SetDimensionAnchor: added anchor_index prop to enter PICK_FACE directly;
  set_active_anchor called at all phase transitions (invoke, vertex-pick,
  face-pick, alt-click free, ESC/RMB) so gizmo color tracks state correctly
- handler._sync_dimension_anchors_to_curve: proximity-based anchor sync
  when curve vertex count changes in Edit Mode (subdivide / delete)
- depsgraph_update_post_handler: regenerates dimensions when referenced
  elements move; also handles annotation curve edits directly
- Remove standalone Set Anchor button from annotation tool UI (replaced by
  clicking a gizmo dot)

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

… layer anchors

- ClickNearestDimensionAnchor: scan all selected objects instead of active
  object so clicking a green dot doesn't lose to the underlying IFC geometry
- GizmoAnchorHandle: remove draw_select entirely (any entry in the select
  buffer causes Blender's gizmo system to consume clicks); keep purely visual
- Scale anchor dots to scale_basis = 0.2
- Fix ReferenceError in decoration.py draw loop after undo by catching
  ReferenceError and resetting DecoratorData.is_loaded
- SetDimensionAnchor: inherit tool.Ifc.Operator so IFC pset writes are
  tracked for undo; finish the modal after each face write so each anchor
  gets its own undo step
- Fix ReferenceError in _modal after undo when annotation RNA is freed
- handler.py: add regenerate_dims_for_layer; call it from
  EditMaterialSetItem._execute so dimensions update when layer thickness changes
- regenerate_dimension.py: fix ForcePerpendicularToFace for LAYER_BOUNDARY
  anchors by deriving the thickness-axis normal from LayerSetDirection
  (AXIS2→Y, AXIS1→X, AXIS3→Z) instead of requiring a stored normal_local

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

…for DrawParametricDimension

- DrawParametricDimension: TAB cycles snap mode FACE→LAYER→EDGE→VERTEX during
  placement; consumes both PRESS and RELEASE when not in input mode to avoid
  conflict with polyline Cycle Input
- DrawParametricDimension: IFC-native snap candidate overrides polyline cursor
  position in LAYER/EDGE/VERTEX modes; FACE mode shows polygon outline; reuses
  _snap_draw_data / _draw_snap_indicator_global infrastructure from SetDimensionAnchor
- DrawParametricDimension: LAYER_BOUNDARY support in _update_perp_constraint,
  deriving normal from LayerSetDirection (AXIS1/2/3)
- ClickNearestDimensionAnchor: scan all visible annotations instead of only
  selected ones — view3d.select deselects the dimension before this operator
  runs, so pre-selection check caused dots to never activate
- AnnotationTool keymap: bim.click_nearest_dimension_anchor placed before
  view3d.select so it fires first when the annotation tool is active

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

- Remove clear_snap_objs() from PolylineOperator.invoke — BVH cache now
  persists across invocations; per-entry staleness is checked in
  create_snap_obj via matrix_world equality + vertex count, eliminating
  the ~11 s full rebuild on every Shift+A press.
- Add _init_snapping_points() hook to PolylineOperator; DrawParametricDimension
  overrides it with a cheap plane-intersection placeholder, deferring full
  BVH detection to the first MOUSEMOVE.
- Cache matrix_world in SnapObj and replace O(N_vertices) validation loop
  with O(1) matrix equality + single sample vertex check, cutting per-call
  create_snap_obj cost from 22-600 ms to <0.2 ms on cache hits.
- Use scene-level BVH pierce-through in SetDimensionAnchor._compute_candidates
  instead of per-object ray_cast loop (O(log N) vs O(N_objects)).
- Guard PolylineDecorator snap_mouse_point access against empty collection
  to prevent IndexError before first MOUSEMOVE populates the property.
- Wrap closest_point_on_mesh in try/except RuntimeError in
  _update_snap_draw_data for annotation objects with no internal mesh data.

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

…nsion

Vertical faces perpendicular to the camera cannot be hit by raycast, so
the dimension snap tool missed them entirely. Fix by checking nearby
objects whose 3D bbox contains the floor hit point and running
mode-appropriate candidate lookup on each:

- FACE mode: _snap_on_coplanar_faces finds vertical mesh faces with a
  bottom edge at the hovered Z, projects the cursor onto the face plane,
  and returns a FACE candidate (blue outline + face snap point).
- LAYER mode: get_layer_snap_candidates now runs on nearby bbox objects
  the same way VERTEX/EDGE mode already did, using the shared
  _snap_cand_multi_cache (cleared on TAB mode switch).

Both PR #7965 (inset_section_endpoints) and PR #8083 (parametric_dimensions)
independently added properties after entry #33 in Psets_BBIM_Annotation.ifc
and new BoolProperty declarations after `type_name` in prop.py and workspace.py
UI rows at the same locations.

Resolution: keep #8083's IDs (#34-#40) unchanged, renumber #7965's
IsManualDrawingReference and IsDocumentReference entries to #41 and #42,
update EPset_Annotation reference list accordingly, keep both UI rows,
and combine hotkey_S_A to use #8083's parametric-dimension routing
with #7965's "INVOKE_DEFAULT" argument for add_annotation.