   XNA:  Transforming a world space matrix into screen space
  I'm back again asking a question related to graphics.  When I am rendering My (2D)scene graph what is the fastest way to translate all of it's nodes into screen space?I have a camera matrix that contains the world orientation of the camera.  Each renderable object has a world space matrix.  I figured I could concatenate the camera's matrix and each node's world matrix but that would not work. How do I use the camera's matrix to translate a world space matrix into screen space? I'm using XNA and C#    