# Cutting a circular hole into a sphere without artifacts

I'm building a set based around a 500ft diameter sphere.
The entrance is a 50ft diameter hole through the 10ft thick wall of the sphere.

However using Booleans to make the hole in the sphere is basically a dead end. With an entrance hole that large, you have to use a cylinder with a minimum of more than 90 vertices to really get it to look truly round.

I have absolutely NO choice as to the dimensions of the hole or it's positioning — it has to be precisely 50.00ft in diameter, and precisely 13.5degrees above a horizontal plane through the center of the sphere.

And without being able to fool with the diameter and positioning of the hole you get artifacts.

I've tried transferring normals, but light reflecting off the surface of the sphere, especially in an animation, looks really off..

I've tried editing the mesh to get rid of shallow angles and the like. But it took forever with just 48 vertices on the cutter, and just was not worth the time. The hole didn't look smooth, and there were still artifacts showing up in reflections.

The only way I found to get rid of ALL of the artifacts was to shrinkwrap a 50.00ft diameter circle onto the sphere using project, joining it into the mesh of the sphere, using loop tools to circularize parts of the sphere's grid, then do a heck of a lot of cutting, pasting, moving, and editing geometry to position it where it needed to be. But that technique forced me to use a 50ft circle with the same number of verts (16) that the nearest loop it had to be bridged to had (which was 16).

And you can see the result. No artifacts, but a hole that's more of a polygon than a round hole.

Does anybody have any suggestions on how I can smooth out the flat looking planes in that hole to make it look round? I already tried subdividing it. That gives me more geometry to work with but the planes just look like subdivided flat planes no matter how you try to autosmooth it.

• Have you tried subsurf? Commented Dec 29, 2021 at 11:31