I would like to draw a tri-axial ellipsoid (that is, an ellipsoid with three different main axes). I'd also like to draw a sphere in the same picture, showing the curves of intersection between the sphere and the ellipsoid. I have seen TikZ code that makes a ellipsoid, but it's always an ellipsoid of rotation, so with the same x and y size.
In principle, it is enough to have solid shapes for the ellipsoid and the sphere, longitudinal and latitudinal planes are not necessary.
Could anyone help me with this/show me some example code for a tri-axial ellipsoid?
I would prefer to have a 3D image, e.g. like Example: Stereographic and cylindrical map projections. At the moment, it looks something like this (the white lines are artefacts of the jpg conversion),
but I'd like to improve it.