PBR Material Value Cheatsheet
Reference F0, albedo and roughness values for metals and dielectrics, with sRGB conversion and a base-colour validator.
About this tool
PBR Material Value Cheatsheet
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.
How to use PBR Material Value Cheatsheet
- 1
Open PBR Material Value Cheatsheet on AltFTool — it loads instantly in your browser.
- 2
Enter your texture's Base colour R, G and B (0-255 sRGB) plus Metallic (0 or 1) and Roughness (0-1) under Check a base colour.
- 3
Read the check output - linear values, relative luminance, GGX alpha, Blinn-Phong exponent and the closest reference material - with any out-of-range channels flagged.
- 4
Look up measured figures in the Reference values table via the Search materials box (gold, concrete, metal...), or press Copy values to copy the whole check.
Why use PBR Material Value Cheatsheet
Linear and sRGB side by side
Every material shows both, so you paste the right one into the right slot.
Range checking, not vibes
The validator names the specific channel that falls outside the dielectric window.
F0 from IOR
The Fresnel equation is applied directly, so glass lands on 0.04 and water on 0.020.
Common use cases
- Check whether a hand-painted base colour is too dark before it kills every bounce in the lighting.
- Look up gold, copper or aluminium reflectance instead of eyedropping a photo that already has lighting baked in.
- Convert a specular-gloss value to metallic-roughness when porting an older asset library.
- Settle an argument about how bright concrete or asphalt should actually be in a scene.
Frequently asked questions
What base colour value should a dielectric have?
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.
What is the F0 value for a non-metal?
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).
Should metallic ever be a value between 0 and 1?
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.
How do I convert roughness to a Blinn-Phong specular exponent?
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.