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About this tool
Reference F0, albedo and roughness values for metals and dielectrics, with sRGB conversion and a base-colour validator.
This cheatsheet lists the reflectance values physically based rendering expects: measured F0 for metals, diffuse albedo for dielectrics, and the roughness ranges each finish usually falls in. It converts every value between linear light and 8-bit sRGB using the IEC 61966-2-1 transfer function, derives F0 from an index of refraction with F0 = ((n − 1) / (n + 1))², and flags base colours that sit outside the plausible authoring window. It is written for 3D artists authoring metallic-roughness materials.
Open PBR Material Value Cheatsheet on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
Every material shows both, so you paste the right one into the right slot.
The validator names the specific channel that falls outside the dielectric window.
The Fresnel equation is applied directly, so glass lands on 0.04 and water on 0.020.
Keep every channel roughly between 50 and 243 in 8-bit sRGB. Fresh asphalt and charcoal, about the darkest real surfaces, encode to around 56, and fresh snow, about the brightest, reaches only about 232 — pure black or pure white base colours cannot occur in nature.
Most dielectrics sit near 0.04, which is what an index of refraction of 1.5 gives through F0 = ((n − 1) / (n + 1))². Water is lower at about 0.020 (n = 1.333) and diamond much higher at about 0.172 (n = 2.42).
No, other than in the blend pixels where a metal meets a coating, dirt or paint layer. A surface is either a conductor or it is not, so intermediate metallic values usually mean the mask needs fixing rather than the value.
Square the roughness to get the GGX alpha term, then use exponent = 2 / alpha² − 2. A roughness of 0.5 gives alpha 0.25 and an exponent of 30; the conversion is approximate and breaks down as roughness approaches zero.