Adds geometry primitives the viewport clip-box feature needs:
- obb_world_clip_planes / obb_clip_planes_from_matrix: derive the 6
inward clip planes of an oriented bounding box (or unit cube under
a matrix_world) in RegionView3D.clip_planes form. expand / expand_rel
margins let callers visualising the box with overlapping geometry
(an empty CUBE display sharing edges with the planes) keep the box's
own wireframe inside the clip volume.
- point_is_inside_clip_planes / corners_might_cross_clip_planes: cheap
reject tests for the per-mesh capping pass to skip the expensive
bisect when an object's AABB is fully outside the box.
- newell_normal / plane_basis: robust planar-ring normal for thin
near-degenerate cap rings where a two-edge cross product is unstable.
- tessellate_ring_planar: triangulate [outer, *inners] 3D rings in the
outer ring's best-fit plane, with a shapely constrained-Delaunay
fallback for the known failure mode of mathutils.tessellate_polygon
on complex concave polygons-with-holes.
Tests cover unit-box, translated, rotated, and scaled cases for the
OBB-from-matrix builder + the rejection helpers.
Generated with the assistance of an AI coding tool.
Gorgious56