I have an object that's strangely partly invisible from one side and partly from the other. I.e. when rotating the camera around part's of the object appear and disappear depending on which side they're viewed. When displayed as wireframe, everything is there. The object is imported from sketchup, and I've understood sketchup is notorious with f*king up uv's etc. But i cannot fix this even with deleting all point, vertex, primitive etc attributes.