Importing LODs from Simplygon


I’m trying to create LODs for my meshes using Simplygon (the UI, not the plugin).

So, I exported my tree mesh into FBX, imported it in Simplygon, created 3 LODs (other than the base), and generated them.

Now, as I am trying to add them to my Mesh within unreal engine (by going into the mesh editor, and choosing “import LODx”), when the process is done, I get this nasty error message:

has some nearly zero bi-normals which can create some issues. (Tolerance of 1E-4)

As a result, the imported LOD seems off.

When I manually import these LOD meshes as separate meshes, they look great, and I get no error messages, but when I try to add them as an LOD to a mesh, this is what I get.

Any comments?