fix: BvhNode::scale now handles negative scale components correctly#406
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robtfm wants to merge 1 commit intodimforge:masterfrom
Open
fix: BvhNode::scale now handles negative scale components correctly#406robtfm wants to merge 1 commit intodimforge:masterfrom
robtfm wants to merge 1 commit intodimforge:masterfrom
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Previously, scaling an AABB by a negative factor would produce an inverted AABB (mins > maxs on the negated axis), breaking the BVH invariant and causing all intersection/shapecast queries to silently miss geometry. Fix by taking component-wise min/max of the two scaled corners, so the AABB invariant is preserved regardless of sign. The parent-child containment property of the BVH is maintained since scale(merge(A,B)) == merge(scale(A),scale(B)) holds for any non-zero scale. This unblocks use of TriMesh::scaled with negative scale (e.g. reflections).
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check/update bvh for negative scales and remove arg condition. this condition was not mentioned in (at least)
TriMesh::scaled_by, doesn't seem expensive to check correctly, and is on an infrequent codepath.--
Previously, scaling an AABB by a negative factor would produce an inverted AABB (mins > maxs on the negated axis), breaking the BVH invariant and causing all intersection/shapecast queries to silently miss geometry.
Fix by taking component-wise min/max of the two scaled corners, so the AABB invariant is preserved regardless of sign. The parent-child containment property of the BVH is maintained since scale(merge(A,B)) == merge(scale(A),scale(B)) holds for any non-zero scale.
This unblocks use of TriMesh::scaled with negative scale (e.g. reflections).