Camera Projection
Function
Allows the user to quickly create a projection line, starting from a camera's position.
Requires at least 1 camera to be present in the scene.
Procedure
Make sure you have at least 1 camera present.
If only 1 camera is present, this routine will auto-select said camera
If 2 or more cameras are present, it will prompt you to select which camera to use
Run the routine
Select which camera to use (in the case of multiple cameras present)
Select the end point of your projection line