How to get 2D shape of the mesh/collider on screen?
do you have example screenshot?
in what format? list of Vector2’s, or as a texture (with alpha), or something else?
is the mesh/collider 3D object? does it have holes, is it convex vs concave?
Both Vector2 and texture are required , yes it is 3D object , it dont have holes, Both convex and concave are required .
Had a nice thread about this with a good result here: How do I make a UI element resize with a 3D object?