Reference
Illetschko, T., Ion, A., Haxhimusa, Y., & Kropatsch, W. (2006). Distinguishing the 3 Primitive 3D-topological Configurations: Simplex, Hole, Tunnel. In Proceedings of the 11th Computer Vision Winter Workshop (pp. 22–27). http://hdl.handle.net/20.500.12708/51548