MAYA: How to reuse parts of a Diffuse texture without overlapping UVs on top of it?

Development Rendering
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1

So apparently Unreal does not like when UV are stacked on top of each other when baking lights. If I have overlapping UVs in Maya then the engine has broken light baking.

Essentially I Usually have a model with a pre-set/made Collage of textures and then reuse those textures by OVERLAPPING or STACKING UVs on to of one another over that texture. The Problem is that this is what is causing the broken baking in the engine. My question is, Is there a way to Have two Different faces use the same part of the texture but without having them overlap/ Being stacked on top of each other?

2

Try adding a 2nd UVSet in Maya with unique UVs, then tell the engine to use that channel for light mapping.

You can adjust the UV channel used for lighting in the static mesh settings “Light map coordinate index”. Note indexes start at 0.

Hope that helps.

3

You shouldn’t care if the first UV channel has overlapping UV’s, that’s fine :slight_smile:
You do need to create an additional UV channel in maya (or let ue4 generate it) (which will be UV channel 1) for the lightmap.

So UV’s for diffuse in ue4: UV channel 0
UV’s for lightmap in ue4: UV channel 1

There are some occasions where you will need more than these two uv maps, but for basic meshes this should be fine.

4

Well I have tried adding the new UV set in Maya and making sure that none of the faces overlap with its UV coloring But that seems to be giving me a headache. I want to try to make the UV set within UE4. Do you happen to know a tutorial around here that tells how to create a new UV set within UE?

just perhaps it would save time from re-opening asset files and re-exporting them.

Thanks

5

In the static mesh viewer choose window/generate unique UVs. you will see another subsection in bottom of the details panel. The settings there are pretty straight forward. This will generate unique lightmap UVs for you based on the UV channel you specify.

6

It is highly suggested (though it also depends on the mesh and its UV layout) to create a new uv map using the uv’s from channel 0.

It often gives the best result. (from personal experiences at least)

7

Hmm… Maybe your vertexes in the uv-creator arent welded?

8

Yes, I find that at times its “NEW” UV layout wastes too much of precious space. On the other hand when it bases the UV set from the other ones, it completely splits everything into triads.

9

Perhaps but for as long as it doesn’t touch the diffuse UV set and bakes light properly (as thus far it has) then I think it doesn’t matter much.