nx_castview.nx

nx_castview.nx -- render a mesh3 by RAY-CASTING into (textured image, EXACT depth map). WHY: every reconstruction test in this arc has used a flat synthetic plane. That validates the maths but not the case that matters -- a real machined part with curvature, facets, holes and silhouettes. Real PHOTOGRAPHS are the eventual gate, but they are not the only way past a plane: the as1 STEP file gives REAL CAD part geometry, and ray-casting it produces views WITH exact ground-truth depth per pixel. That turns the whole chain into SCAN-vs-CAD dimensional inspection -- reconstruct a part, compare the result against the CAD it came from -- which is a named twin capability and needs no camera. ⚠SCALE: r3_ray returns a Q14 (R3_Q) unit direction; mtk_ray_tri works in fx256. Converting between them is mandatory -- feeding a Q14 direction to the fx256 caster silently mis-scales every hit distance. license_tier: ORIGINAL