UE Sampling Color For Indirect Only From One Texture (Vertex Paint)?

[GabBD]

Hi!

I’m using a vertex paint material that blends between 3 textures. However, I’ve noticed that UE seems to sample only the top diffuse when it comes to injecting color into the lightmass. I tried using layered materials, replacing the GI, using something else than Lerps, but it didn’t change anything. Is it simply a limitation on Unreal’s part?

I’ve recreated the problem with a very basic material:

As you can see, the whole material injects green into the scene and onto the spheres.

Whether it’s a constant3vector or a texture sample, whether it’s plugged in the base color directly or passed through a GI replace, it’s still the color layered on top that gets sampled.

If anyone knows if it’s a limitation of the engine or something I’ve goofed, please let me know, it’d be super appreciated!

Thanks!

[Deathrey (DeathreyCG)]

Yep, that is limitation of Light mass. It will ignore vertex color. Situationally, there are workarounds. For example, you can pre-bake vertex color to a texture and use this texture for blending, instead of vertex color, while using GIreplace material expression. GIreplace separates part of your material graph to be used only for lighting calculations.

[GabBD]

Alright thanks a lot!