Is there a way to stop unreal engine from refreshing the viewport?

I want to occasionally stop refreshing the viewport so the previously written data to camera be kept and new one be added to it. I know some close approximation can be achieved by scene capture but it is not as accurate as i want it.

I want to create a flowfield that gradually completes like in this video but refreshing the viewport is the only hinder here

I have the same question. Have you found how to do it?

no progress. this is quite easy to do with unity camera actor. but not in unreal engine 4

Is there still no way to do this?