does anyone know of GPL (preffrably MIT) code for computing a concave hull of a 3D point set. I know there are functions in CGAL for doing this but I cannot use CGAL atm. If possible a MIT implementation would be nice or even GPL for a proof of concept before I spend the time implementing it myself. Any explanation of some concave / alpha shape algorithm would be good too to better understand how to go about implementing this. I'm struggling to find c++ implementations of alpha_shapes_3/concave hull. I'm looking for other implementations other than CGAL essentially or an explanation of alpha shapes algorithm.
Thankyou.
[EDIT:] Put another way... is there anything other than CGAL which does 3D alpha shapes, MIT would be nice to save me doing it, but a dedicated open source project would also suffice which is isolated and not part of a framework. Failing that any information of algorithms for doing this 3D would also be appreciated.