A 3D trimesh shape, intended for use in physics. Usually used to provide a shape for a CollisionShape3D.

Being just a collection of interconnected triangles, ConcavePolygonShape3D is the most freely configurable single 3D shape. It can be used to form polyhedra of any nature, or even shapes that don't enclose a volume. However, ConcavePolygonShape3D is hollow even if the interconnected triangles do enclose a volume, which often makes it unsuitable for physics or detection.

Warning: Physics bodies that are small have a chance to clip through this shape when moving fast. This happens because on one frame, the physics body may be on the "outside" of the shape, and on the next frame it may be "inside" it. ConcavePolygonShape3D is hollow, so it won't detect a collision.

Performance: Due to its complexity, ConcavePolygonShape3D is the slowest 3D collision shape to check collisions against. Its use should generally be limited to level geometry. For convex geometry, ConvexPolygonShape3D should be used. For dynamic physics bodies that need concave collision, several ConvexPolygonShape3Ds can be used to represent its collision by using convex decomposition; see ConvexPolygonShape3D's documentation for instructions.