I am making a shipping container and on the doors there is a shading or normal problem, I checked the number of edges for each face and they're all 4 edges, any suggestion?
Hard vs soft edges. On those sort of angle changes, you'd want to put a hard edge, so it doesn't try to average the normals/tangents at those extreme amounts. https://www.youtube.com/watch?v=sTJ-pryZFQk