4.8 Material roughness issues

So I’m looking into the possibility to upgrading to unreal 4.8. I like some of the new lighting features and post process effects. I’m having an issue with materials mainly for the roughness portion of them. I have materials that are built similar to the xoio berlinflat scene. When I open of the scene in unreal 4.8 the roughness maps are popping up like there multiplied to the base color or diffuse. its making my materials and environments darker. Here is a pic of the Berlinflat scene so you can see what I’m talking about. If anybody has any suggestions on how to fix this that would be awesome.

thanks

Hello dragonfly2,

Roughness is calculated on a 0 to 1 scale. Like an alpha map. 0 corresponding to no roughness and 1 to completely rough.

This can be applied to materials as well as lights.

For materials this means a rougher material will reflect light in more directions than a smooth material will. A smoother material with less roughness will yield a more metallic reflective surface.

I will link you our official documentation on PBR shaders and this should clarify what each input for a PBR workflow will look like and what each one means.

https://docs-origin.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html

Hope this helps,

Hey , I get how roughness works. What I am concerned about is why its different in 4.8 vs 4.7? that’s why I posted the pic of the Berlinflat, you can really see the difference in the roughness map. There both the same materials, textures and geo. Nothing has changed from either version. You can see in the pic or in the map that in 4.7 the walls have a hint of the splotchy roughness from the texture. But if you look at the same wall in 4.8 its really apparent and the roughness texture looks like its being multiplied to the base color even though its not.

Hello dragonfly2,

If you would link me your content, config, and .uproject files. Then I can test out this issue on your project without trying to create a test project and guessing at the issue.

Thanks,