Edge-collapse decimation (meshopt_simplify) returns BIM meshes unchanged
due to per-triangle vertex duplication and non-manifold topology. The
sloppy voxel-clustering decimator is faster, needs no shadow index
welding, and produces good results at the sub-30px LOD1 threshold.
Remove the non-sloppy branch, shadow buffer, IFC_LOD_SLOPPY and
IFC_LOD_LOCK_BORDER env vars.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Dion Moult
5161b0a3f8