Mixed reality VR Gameplay

Has anyone tried to do this type of capture in Unreal?

How could this be achieved?
They explained that they have attached one of the Vive controllers to a real camera so the real camera matches the camera movements in game, but I am unsure on how to record the ingame camera that is filming the player.

Is it necessary to do multiplayer so one player in one computer is the camera and the other player on the other computer is using the HMD?
Or is there another way using only one computer? Would it be possible to have the second camera recording the player while the main camera is still the HMD? How would those frames of the secondary camera would be saved to the hard drive?

Thank you

I wouldn’t be surprised if this wasn’t composited in a movie editor e.g. after effects.

That said you can get a second camera on the same client via SceneCapture2D.

You would need sync the position of the camera capturing the footage (3rd vive controller?) with the scene capture cube position and orientation. Then you’d have two matched streams (make sure to save them somewhere) that you can composite how you want to in editing.

For what they have explained, they film the person in green screen and then they either composite afterwards or they pass the video masked into a plane , that plane moves according to the HMD position in the 3d scene.
For syncing the real and the virtual camera they indeed use one of the vive controllers, so that part is fairly easy.
Scene capture 2D is also what I was thinking on using, but the problem that I see is.
How do I save this Scenecapture2d camera while the person playing is still wearing the Vive Headset?
Is this possible at reasonable framerate with one computer or should I set up multiplayer and use the second player as camera and just do the recording in the other computer?