AssImp .blend import and Urho3D-Blender export may result wrong normals.
A workaround is to export to .dae/.fbx and then import it with AssetImporter.
Direct .blend import/export, wrong normals:
Workaround, correct normals:
I tested it with this viewer: assimp.org/main_viewer.html
…to make sure it’s a problem with Assimp and not something Urho3D does, and it still happens.
I opened an issue for Assimp:
github.com/assimp/assimp/issues/816
Not sure if Urho3D-Blender uses Assimp, if not it also has this bug.