Hi there! Recently found myself using vispy to create some 3D meshes for regions on the surface of an axis-aligned ellipsoid. Would be happy to have a go at contributing a new geometry class within vispy for others to use if there's interest (and developer time for review).

My aim was to be able to specify the major/semi/minor axes and center of an axis-aligned ellipsoid along with angular ranges so that I could plot full ellipsoids or just sections of the surface.

e.g., full ellipsoid:

or half an ellipsoid:

or smaller angular ranges on the surface:

The implementation is over in one of my scratch repositories. It'd take me a bit of effort to refactor to be a proper vispy.visual class but I don't think too much, but wanted to check in before I set out to do that... relevant links:

• The current implementation is at https://github.com/chrishavlin/miscellaneous_python/blob/main/src/vispy_ellipsoids/vispy_helper/ellipsoid.py (note I did use numba here to speed up some looping but i don't think it's really necessary, it's not too slow without it).
• A script using it https://github.com/chrishavlin/miscellaneous_python/blob/main/src/vispy_ellipsoids/ellipsoid_viewer.py
• the directory containing those two files: https://github.com/chrishavlin/miscellaneous_python/tree/main/src/vispy_ellipsoids

let me know what you think. also let me know if this functionality already exists in vispy but I missed it :)