> Ellipses, which seem like they should be pretty easy, are actually very difficult. Been there, felt that. Surprisingly this came up several times in my care

> Ellipses, which seem like they should be pretty easy, are actually very difficult. Been there, felt that. Surprisingly this came up several times in my career in different contexts. Iirc there is one relatively good heuristic and several iterative methods to calculate point to ellipse distance (and therefore collisions).