I am interested in using measurement data of real materials to create as-close-as-possible replicas in Unreal Engine 4. The materials I examine range from lacquers over plastics to fabric and wood.
What I have:
- Spectral measurement data for various viewer / light angles (XRite CxF files)
- Scanned ‘diffuse’ textures, using a common desk scanner
- Measured height data
- Normal map created from the height data
I am able to convert the spectral data to sRGB, and use it to color-grade the ‘diffuse’ scan. I could use some insights on the following questions:
- How exactly is ‘base color’ defined in UE4? Is it after all the ideal diffuse color, or something else? Some measured base colors can be found here. How were they measured?
- How exactly is ‘roughness’ defined in UE4? Any chance of calculating a roughness value from my measured spectral data?
- How to distinguish ‘roughness’ from ‘specularity’, which is still there? Some measured specular values can be found here. How were they measured?
If you could give me some hints or point me in the right direction, I’d appreciate it.