Hi Stefan - I cooked up one attempt which is attached. To install it unzip it and copy the 2 files into the \commands sub-folder underneath MoI's main installation folder. That will then make a new Circumcenter command available to MoI to run - set up a keyboard shortcut with that as the command name to trigger it.

It expects to have input in the form of a bunch of separate individual line segments that touch at their endpoints to form a triangle structure like this:



So those are not joined to each other, they are a bunch of separate lines.

Select those before you run the command and it will generate a point at the center of the circle that goes through each triangle's vertices:



Let me know if it doesn't seem to work properly, it is not tested too much.

It just works by getting the endpoints of whatever curves were selected, it doesn't actually check if they are lines or not.

It's kind of brute force and a bit sluggish but it should still beat creating them by hand by a long shot. :)

EDIT: Updated it with a new attachment - the new version can take either lines or solids made up of triangular faces for the selection - the solids method is much faster and should work better for processing a larger amount of stuff all in one go. To use the solids method select the whole solid itself, not its edges.

- Michael