Making unphotographed bottom of 3D models solid

ShadowTail wrote:

In that case you may want to try some post processing in something like Meshlab.

That will allow you to close such holes.

I was afraid of that. If all else fails I’ll download Meshlab.
It’s a little frustrating, because I kind of did it by accident with this model, and I can’t figure out how to recreate the circumstances that led to it:
https://sketchfab.com/models/391c3660b1 … 44e27af0a2