coatedFinish

Two-layer finish shader for the metallic and pearl car paints, the stylised candy paint, the carbon fibres and the diner vinyl of syntheticsMaterials. The base (tilted aluminium or mica flakes, painted flecks, or woven carbon tows) is lit with its own normal map; a smooth clear coat on top is lit with the surface's geometric normal (or follows the base, coat_follows_base), both through the engine's own PBR lighting (every light, shadows and the environment), and combined with the coat's Fresnel. The engine's pbr clearcoat shares the base's bumpy normal, which is why this exists. The mask packs occlusion, roughness, flake coverage and the sine of twice the fibre angle; the base colour's alpha carries the cosine, so each tow or forged chip has its own highlight direction. Base roughness widens with screen-space normal variation, so flakes and tows below a pixel average out instead of shimmering.

Glints (sparkle, sparkle_cells, sparkle_tilt, sparkle_cone): a UV grid of cells each holding one randomly tilted flake (tilts spread as a gaussian with a wider tail); a flake flashes when it reflects the sun or a distant, point or spot light to the eye. Cells coarsen with distance and the glints fade once a pixel holds enough flakes that one always catches the light, so there is sparkle up close and none at 30 m. Colour travel (flake_edge_color, flop, flop_power, flop_body): the flakes' colour, and with flop_body the base coat's, moves from flake_color (face-on, near the sun's mirror direction) to flake_edge_color (away from it and toward grazing). relief_fade fades large regular relief by pixel footprint so it never moirés. The capture tool's albedo, roughness and metallic passes read the base layer.