Subject Depth in Unity / Lightcraft

Until now, we rendered the camera image on top of the Unity camera view, where the Previzion Lightcraft software has this neat feature where you can change the subject depth (distance to the camera).  This allows you to put virtual objects in front of the subject, or put the subject inside a virtual car (image courtesy of Lightcraft)

The same functionality is now implemented in our Unity project by writing a script that changes the scale of a textured quad so that it always fits the screen, at any depth.