nx_cube3d_gate.nx

nx_cube3d_gate.nx -- a REAL 3D SCENE: a rotated, perspective-projected CUBE rasterized with the Z-buffer. 8 verts -> rotate (Y then X, fixed-point Q10) -> perspective project -> 12 triangles (6 faces x 2), each a face color, depth-sorted by nx_depth_tri. NO backface culling needed -- the DEPTH BUFFER decides visibility, so exactly the near faces show. This composes the depth primitive into "we render 3D objects with occlusion." T1 depth-on frame != painter's frame -> the Z-buffer is actually resolving occlusion in the scene. T2 all 3 front-facing face colors (red +X, green +Y, blue +Z) are present -> 3 visible faces, a real cube. T3 center pixel is a face (non-black) -> the cube is on-screen and solid. Artifact: knowledge/nx_cube3d.png (viewable 3D cube). license_tier: ORIGINAL expect_exit: 0