BD Planar Grouping

Structure-aware mesh segmentation into planar regions. Groups connected faces by normal direction (angle threshold). Marks boundary edges between groups as SHARP for decimation preservation. BOUNDARY STRAIGHTENING (Option 2): - Enable 'straighten_boundaries' to project vertices onto fitted planes - Boundary edges become straight lines where planes intersect - Interior vertices are flattened onto their group's plane - Creates clean, geometric boundaries instead of jagged mesh edges Use BEFORE decimation to preserve flat-shaded planes: 1. BD_PlanarGrouping → marks group boundaries (+ optional straightening) 2. BD_BlenderDecimate → preserves marked edges with delimit Parameters: - angle_threshold: Max angle between normals in same group (lower = more groups) - min_group_size: Merge small groups into neighbors (reduces noise) - straighten_boundaries: Project vertices to make boundaries straight lines - color_by_group: Apply distinct colors to visualize groups