Subdivision Surface Artifacts / Topology Issues? I am trying to create an archway and getting this little artifact with subsurface. I've tried a few things, moving some geometry around but unable to get rid of it. Any insight as to what I need to do to fix?



Looking closer at the underlying geometry created by subsurface makes it appear that an ngon is being created at this corner.
You may consider retopologizing it a bit (changing the edges flow). Here's my proposal:


This kind of geometry doesn't create the shading artifacts plus allows you to properly crease the subsufed mesh with edge loops.