3d projection (nuke)

A useful 3d camera projection technique i like using a lot.
1. Take main animated cam and duplicate

 
2. create user knob on the camera then copy "(projFrame)" on the end of each animated attr on the camera
3. Set the frame on the new knob to the frame the projection matches with the current frame.
4. connect it up to project 3d node and then a card then into the scene node