From a newbie to all of you with lightmaps / shadow problem

Development Rendering
1

Hey all,
I was getting nearly insane figuring out was wrong with my mesh. I got strange shadows and overlapping uv problems. I figure out something that I have not found in the forums anywhere.

  • When importing a mesh from your 3D program ( Blender in my case) DO NOT! export eks. 2 meshes in 1 FBX file. This will get you lightmaps problem that are not solvabel within UE , you will for sure have overlapping UV because UE take both meshes
    under one, the result will then be overlapping UV. For you the expert this make you probably say: " ofcourse" But since I allways have worked with 3D applications, this have never been any problem.

  • So therefor fellow newbies here a some thumbrules to follow:

  1. Export only 1 mesh in 1 FBX file. If you have the need to export two meshes, then join them. In blender use CTRL-J, and then create UV’s
  2. Create a second UV Channel for the lightmap. in Blender you do that here: c928ab2c84fca2571f1715c23f5cb867b0d00e6f.jpeg

Please to you expert, if this is somewhat wrong correct it ! or are there any other rules?

Esim (newbie)