Problem on making mixed reailty output in unity3D

Hi, I m new on Unity3D ,and I m working on a unity project (not game from game store) that need to shoot MR video…but i get the problem to show up the 4 quadrants view properly.

Here is my step:

My unity3D is 5.50f3 version with steamVR version 1.2.1 pulgin installed , and I also have a third controller attached correctly.

I create a new scene in unity and add the cameraRig ,SteamVR and the SteamVR_ExternalCamera from the Prefabs.I have the External Camera Config Path assigned then I...

Problem on making mixed reailty output in unity3D