title: Point-triangle intersection in 3d from mouse coordinates?
body: <p>I know how to test intersection between a point and a triangle.</p>
  
  <p>...But i dont get it, how i can move the starting position of the point onto the screen plane precisely by using my mouse coordinates, so the point angle should change depending on where mouse cursor is on the screen, also this should work perfectly no matter which perspective angle i am using in my OpenGL application, so the point angle would be different on different perspective angles... gluPerspective() is the function im talking about.</p>