Create 2D shapes in an instant with the PolyMesh editor! Right in Unity you can create polygons, add, split, extrude, and move around vertices to build the shape you want. If straight edges aren’t good enough, connect vertices with curves to get nice smooth shapes. Great for developing 2D games, quick prototyping, or even just creating odd-shaped colliders!
Also, using a polygon2d collider to create a 3dMesh that can be used mesh colider.
Polygon editor (Crete a mesh with texture and can create a polygon collider 2d.
Convert the polygon collider 2d to a Mesh.
Note: This is a very old project. 2D Sprite Shape or ProBuilder are good alternatives.