PHLEGM v8 Checkpoint 78 - Metallic Near-Coplanar Average Normal Lighting
Parent: Checkpoint 77 - solid bright faces preserved at all yaw frames by exterior silhouette wire and one-sided crease wire.
CHOP metal now uses a neutral silver/white base with Blinn-Phong specular highlights. Per-corner smooth normals are the area-weighted average of vertex-sharing surface normals within the FEATURE-ANGLE limit (default 5 degrees); sharp creases are not smoothed.
Barycentric interpolation shades each front-facing depth-tested visible polygon fragment from these averages. The black feature-edge overlay is applied after face lighting and is never modified. Back/occluded polygons and near-coplanar polygon seams have no wire.
Data-driven definition: PRESENTATION ISO-YAW ... METALLIC-WHITE ... BLACK-FEATURE-WIRE ... CULL-BACK, and SURFACE-LIGHTING BLINN-PHONG NEAR-COPLANAR-AVERAGE-NORMAL. Same 5-degree FEATURE-ANGLE controls normal blending and wire suppression.
All nine models preserve <=16 frame bake, original physical sizes, 5% minimum physical thickness, cutouts, and Windows/Linux shared CHOP rendering. No Python is bundled.
End-user packaging/archival retention fix from checkpoint 76 is retained, bootstrap unchanged.
Validation: updated native FreeBASIC CHOP selftests are included, not executed here (FreeBASIC not installed). Independent reference voxel renderer produced 16-frame white-preserving outlines and sample metallic shading. User-side native compile/visual testing required.
