proper procedure for uv map creation

I’m creating content in modo and I’m used to the workflow of having multiple uv maps on a single mesh object when necessary. For example, if I have a room, I would uv map the walls as it’s own map, another map for the floor, etc. Then when creating my materials and assigning an image texture for the floor, I would tell it to use the floor uv map. I noticed that when I tried to do this and export it from modo, when I then brought it into unreal I got the error message upon import - “unreal-room-test3 has degenerate tangent bases which will result in incorrect shading.” I clicked ok, brought in the mesh to my scene and everything “seemed” to be ok. Before I started playing with materials I only had one uv map on this model and I didn’t get the error, so I suspected the error was due to the multiple uv maps? And if so, I’m assuming that I need to make sure that each mesh only has one uv map? Is this correct? Thanks.

  1. make sure that you have your lightmap on the 2nd uv channel -> :slight_smile:
  2. when those uv’s are always separate materials -> dont use too many of them (draw calls)
  3. make sure that you smoothing groups are correctly assigned
  4. you can solve this error when you do a double click onto your static mesh in the UE4 -> Select the recompute tangents/normals and click save