   How to do collision on XNA??
  Hey  Our team want to create a simple game using XNA.  We want to use the PhysX ageia SDK. But XNA is in C# language while PhysX is in C++ language . So I'm a little confused if I could use the PhysX with XNA.  If it's impossialbe , what else physics SDK could I use with the XNA.Or if XNA can do some collision detection work ??  Really appreciate your help .   Thank you.   
  XNA has simple collision detection. Read the tutorials at creators.xna.com, or the various XNA blogs and tutorial sites around the internet.   ;  You can try to create or find a .NET wrapper for PhysX. I'm sure there are some in works, so you could try that. Note that this will only work on Windows, but it will allow you to use PhysX with XNA.Otherwise there are some physics engines that do work with XNA. In terms of 3D, one of the more popular choices is JigLibX. There is also a Bullet port, I believe, and possibly others. A good Google search will probably turn up most of those.   