I have simplified my asset in 3DS MAX and I have imported it both as an FBX and Alembic and the FBX is correct, whereas the Alembic fails.
In Max, I have created a plane with three UV maps. imported with FBX, the maps hold the scale and position. With Alembic, everything is scaled to 100% and centered.
I see that a few Alembic UV issues have been resolved and I have run tests to verify the results. I am now getting different results than the original Preview build, but still broken. I’m aware that the fixes may not be in the current preview2 release.
That said, I think I may have a different scenario than is being tested. I have uploaded a very simple 3DS Max file to illustrate a problem with Mix Map Layer UVs not being respected in UE4
Sorry about the missing map. Here is the zip file again with the texture map included. You’ll probably have to relink it in Max. However, you shouldn’t really need it because you could place any texture in the material in UE4 and see the problem.
UV Index 0 will show the texture covering the entire object, as it should.
Make sure that the texture in the material is set to UV index 1 or 2 to see the problem
So, I believe you issue is similar to the last time we approached this process. To layer materials on a single object, the composite approach you took is not the supported workflow. I noticed you did not have material id’s assigned to these UV’s which is why the FBX appears stretched and skewed.
This is the workflow we support and the compositing is not expected to work in the same manner without having first established material id’s for each unique material you are calling to render that is mapped to that object.
This is more than likely why neither your FBX or Alembic are rendering similarly and are showing different materials. I highly suggest taking a read over our documentation on multi-material objects to get and understanding of the workflow we support when exporting from Max or Maya into Unreal.
