Computing minimum volume bounding box is a hard problem in computer science. Exact algorithm costs O(n3) time complexity.However, for lots of applications an approximation of the minimum volume oriented bounding box is acceptable and already accurate enough.
http://gabyx.github.io/ApproxMVBB/
Fast algorithm to compute minimum volume oriented bounding box
原文：http://www.cnblogs.com/jast/p/4210133.html