PBR materials explained: metalness, roughness and why presets matter
Physically based rendering in three parameters: metalness, roughness, and clearcoat/transmission for the fancy cases. How the site's 71 presets map onto them.
The two dials every material has
Metalness is binary in practice: metals reflect light tinted by their own color and kill diffuse scattering; non-metals do the opposite. Roughness spreads reflections out — 0 is a mirror, 1 is chalk. Nearly every material in the library is a position on these two dials: chrome is metal 1, roughness ~0; concrete is metal 0, roughness ~0.9.
The extension dials
Clearcoat stacks a second glossy layer over a base — that is how automotive paints and candy finishes get their wet look. Transmission lets light pass through with refraction and IOR, which is all glass really is: transmission near 1, IOR around 1.5. Iridescence shifts the reflected hue with viewing angle — soap bubbles, oil slicks, holographic foils.
Each material page on this site lists its live values, read from the actual shader configuration at render time — not marketing numbers.
Why environment light decides the result
PBR materials have no color of their own in the dark — they describe how to bounce incoming light. Swap the environment and the same preset re-renders: a gold under Sunset looks molten; under Studio it looks like bullion. That is why the editor pairs a material picker with 8 procedurally painted environments.
Reading a preset like a designer
High metalness + low roughness = jewelry register. Zero metalness + high roughness = matte product render. Transmission + roughness midrange = frosted glass. Once you see materials as parameter positions, picking one for a brief takes seconds.