Overlapping UV question

[Gatare]

@darthviper107

For an object you need to have a UV channel where the UV’s aren’t overlapping if the object is going to be using a lightmap.
If your UV’s are fine but just overlapping then you need to copy them to a new UV channel and pack them so that they aren’t overlapping. You can do that all with the Unwrap UVW modifier in 3ds Max.
When you import to UE4 make sure to turn off Generate Automatic Lightmap UV. Set up your mesh so that the first UV channel is for your material, and the second is for the lightmap. By default 3ds Max will assume that the second UV channel is for the lightmap and will set the mesh to use it for that.

Also, while you can use multiple materials on an object, for performance you want to avoid that and if it seems reasonable that you could put it all into one material for that object then you should try to do that. There’s something called Draw Calls, which are commands by the CPU to render something on the GPU, and each material on an object adds a draw call. Performance drops with more draw calls.

Based on that, it sounds like because of the way the models are set up I will need to seperate the peices so the mesh matches the UVs unfortunately.