I have this problem where 3D objects are "hollow" in ksEditor and in-game. I've been trying to solve this problem for some days by using different shaders, materials, and changing normals in Blender, but nothing works.
check face normals, outside/inside, see this https://assettocorsamods.net/threads/build-your-first-track-basic-guide.12/page-77#post-18142
