Grid snap locks to SNAPUNIT instead of magnetizing; snapped 3D points keep elevation instead of flattening to z=0. New SnapTypes Vertex/EdgeMidpoint/FaceCenter/Knot/FacePerpendicular/NearestFace with their own F4 master toggle and mode set, tiers, and markers, fully independent of the 2D master. Solid B-rep corners/edge-midpoints/face-centers from mesh edges and kernel faces, spline knot points, and live perpendicular/nearest-to-face on mesh triangles merged priority-aware in move/click paths. Drafting Settings 3D Object Snap tab is fully live (was dead placeholders); Nearest-to-face off by default. TDD: behavioral LINE-to-solid tests plus engine/scene unit tests.
Refresh associations after complete SpaceMouse camera updates and recognize imported paper-space owners without Layout objects. Use kernel containment, intersection, perpendicular and spline tangent solving; pin cadkernel 7ce27f2 and add regressions.
An `AssocDimensionReference` addresses a feature through a chain of
handles — dimension -> [viewport] -> [insert ...] -> entity -> feature —
stored in `xrefs` (AutoCAD's `mainObjectIds`). The existing resolver read
only `xrefs[0]`. That is right for a model-space dimension on top-level
geometry and wrong for everything else: a paper-space dimension measuring
through a layout viewport has the VIEWPORT first, so resolution stopped
on a viewport entity, found no curve and gave up. Nine of the ten
association objects in the 115448 regression drawing are that shape.
`dimension_assoc_chain` walks the chain positionally, which is all the
file gives us: a leading VIEWPORT is the trans-space hop, INSERTs after
it are the block-instance path (with their composed transform), and the
first handle that is neither is the geometry. A chain of nothing but
INSERTs ends on the innermost one, which is how a block reference's own
insertion point is dimensioned. A handle that is no longer in the
document comes back as `ChainError::Missing` rather than as a silent
failure, so the caller can tell a broken link from an unsupported one.
The module also evaluates the osnap feature itself, in the entity's own
coordinates: centre, midpoint, quadrant, node/insertion, nearest,
perpendicular, tangent (closed form on a circle or arc; a Newton
refinement of (C(u) - P) . C'(u) = 0 on a spline, seeded from the stored
parameter — the shape of the 115448 tangent-to-spline reference), and
intersection / apparent intersection against the second object chain.
Types we do not evaluate return None and keep their stored data, so an
unsupported reference is left unresolved instead of being replaced by a
guess.
`Transform` has no inverse of its own and a block path is always affine,
so the 3x3 cofactor inverse lives here too. All arithmetic is f64.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Karim Jerbi