Overlapping UV's for mobile game?

salimmatta

So guys, is it recommended to overlap UV's in order to gain more texel density for mobile? or might cause of light maps issues when baking light over static meshes?

Eric Chadwick

Yes, no. Use a 2nd UV set for lightmapping.

salimmatta

I'm using UE4, as far as I know it generates light maps UV automatically, or should I do them manually in Maya?

Eric Chadwick

Moving to the Unreal section...

salimmatta

Eric Chadwick said:

Moving to the Unreal section...

Thanks mate

Obscura

It generates one if the checkbox was enabled upon import, or in the static mesh editor , and the new setting was applied. You can always just check out if it made a proper one or if it made one at all, by displaying the uv maps in the static mesh editor. The auto lightmap uv generation works nicely, if the first uv channel is properly unwrapped. it can have overlapping and stuff, but if its a total mess then it won't be able to generate a nice lightmap uv from it. What it does basically, is to take the existing channel, and repack it in a non overlapping way.

salimmatta

Obscura said:

It generates one if the checkbox was enabled upon import, or in the static mesh editor , and the new setting was applied. You can always just check out if it made a proper one or if it made one at all, by displaying the uv maps in the static mesh editor. The auto lightmap uv generation works nicely, if the first uv channel is properly unwrapped. it can have overlapping and stuff, but if its a total mess then it won't be able to generate a nice lightmap uv from it. What it does basically, is to take the existing channel, and repack it in a non overlapping way.

I tried to overlap the UV's, gained more space for texel density but when I baked lights on static meshes and specifically mobile shader, well it looked so bad and not clean at all, so I unwrapped again without overlapping and the results were by far more decent

Mink

You're allowed to have overlapping UVs in your texturing channel, you just have to make your own lightmaps UVs that don't overlap in a second UV channel.