There had already several questions about light-trapping curves, such as drawing a curve captures light or photon-trapping curve, and well known cases had been answered such as ellipse or hyperbola.
With a proper rotation of ellipse or hyperbola, it is easy to find surface can trap light. Except these case which are 2D cases by nature, can we find some true 3D cases which can not reduce the problem to 2D by rotation, mirror operations?
Especially, here I also ask whether a light-trapping path exists in a ellipsoid?