Created in Unreal 4.
This is a layered camera setup I put together because we needed 3d UI that the user could interact with while the world still rendered behind it. This uses two cameras with one acting as a mask. The first camera renders the scene while the second camera only renders the object the user wants to inspect in 3d, and then layers it on top of the first cameras output. Controls are then forwarded between the two cameras when needed.