.blend file here:
After cutting a circle on the cube face with Knife Project and making a hole, I have several questions:
Why the cube looks so bad with Smooth Shading? Apparently normals seem fine. I have found that with the Edge Split modifier I can make it look good, but I do not know if that’s the right way to solve the problem, and I do not know if this method would work with other surfaces.
Why is not possible select the full edge loop in the cube circle cut with Shift+Alt+RMB? I have found that selecting all vertices in the cut and with E to extrude, then I can select the entire loop, but this inserts doubles. What would be the proper way to “connect” these vertices so that the full loop can be selected using Shift+Alt+RMB?
I just realized that the cut has no influence on the first problem (bad look). The problem arises by subdividing the cube. So the first question would be, why does this happen when subdivide the cube? What is the correct method to fix it?