Collision Sample
http://xbox.create.msdn.com/ko-KR/education/catalog/sample/collision

Ray structure
http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.ray(v=xnagamestudio.40).aspx

BoundingSphere structure
http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.boundingsphere(v=xnagamestudio.40).aspx

BoundingBox structure
http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.boundingbox(v=xnagamestudio.40).aspx

BoundingFrustum class
http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.boundingfrustum(v=xnagamestudio.40).aspx