How to get atlas uniformity with trees that share material set-up?

[dunniway]

I am making multiple versions of the same type of tree that all use the same textures and material setup. I'd really like all the trees to share the same UV one draw call atlas set-up. Unfortunately it's a bit of a gamble to get them all to atlas their UVs all the same. It looks like the scale of the trees seems to be a factor in how the UVs get atlas'd... a smaller tree will get a different atlas layout than a bigger one. Is there a way to hand-compile the atlas or set up the materials in a way that guarantees a consistent atlas between trees that share all the same textures and materials? Right now I'm just tweaking the material atlas scale values and crossing my fingers, which isn't really working.

This is for UE4 and SpeedTree Modeler 8.4.2.

Thanks!

[Greg Croft]

Yes, the tree is unwrapped to maintain an even texel density over the whole thing, so different trees might unwrap slightly differently.

But you can get them all to use the same atlas. Open all the variations at the same time in the Modeler. Then when you export to game, additional options for combining all the open trees will be available in the export dialog. They will merge materials and share the same atlas UV space this way.

Hope this helps

[dunniway]

That worked! Brilliant.

Thanks.