CGAL 5.2.1 - 3D Alpha Shapes
Bibliography
[1]

F. Bernardini and C. Bajaj. Sampling and reconstructing manifolds using alpha-shapes. Technical Report CSD-TR-97-013, Dept. Comput. Sci., Purdue Univ., West Lafayette, IN, 1997.

[2]

H. Edelsbrunner and E. P. Mücke. Three-dimensional alpha shapes. ACM Trans. Graph., 13(1):43–72, January 1994.