hello ! I''m using obb (oriented bounfind boxes) in my game to detect collisions, and it works well to detect collisions between translating objetcs, but I dont know how to detect collisions efficiently when the colliding objetcs are rotating. The only algo I found on this subject on the web used lots of calculus and derivated functions, but it just seemed to slow to fit in a real-time game. The other solution is to just compute wheter the obb overlap at the end of the frame, but there is a risk of "missing" a collision, especially with hight speed objetcs. Or I could compute the objets'' positions at several time during the frame, but it would heavily increase the time of computing. So I wondered if you have any suggetions to solve this problem ? Tang