Voronoi splitscreen

I am trying to replicate this effect shown in the video, I know that you just create a render target with a scene capture, and blend between it and the actual scene with a post process material. But I am a bit confused as I have created this post process but cant get anything to apply. Voronoi Split Screen: A Quick Tour by MattWoelk

Hope it helps

https://forums.unrealengine.com/development-discussion/rendering/109228-efficient-voronoi-split-screen