Design Nomenclature / Surface & Material
Clearcoat
Also called clearcoat, coat layer, coating lobe
A second specular lobe layered over the base material to stand in for a transparent coating — car paint, lacquered wood, wet plastic. It carries its own roughness and a fixed IOR near 1.5. Its thickness control only tints by absorption; the layer has no simulated depth and no parallax.
Not to be confused with
- GlossThe degree to which a surface reflects specularly rather than diffusely — and, unusually for this vocabulary, an actually measured quantity: a gloss meter reads gloss units at a fixed angle, 60° by default, 20° for high gloss, 85° for near-matte. High gloss returns a legible image of the room.
- TransmissionThe fraction of light passing through a material rather than reflecting or being absorbed, bent by the IOR on entry and exit. Unlike opacity, transmitted rays refract, tint by Beer–Lambert absorption over the distance travelled, and can focus into caustics. Thin-walled variants skip the refraction, which is how window glass renders cheaply.