Centerline : some results
Centerline displayed properly only when the camera is placed on a centerline point.
Change from World to Camera coordinates (-1.0 to 1.0) using the world to local transformation which also acts as the view matrix.
Change from camera to screen coordinates by multiplying by 512.0 .
Centerline not properly displayed for all points, and when camera not on centerline. Possible error in setting the projection.