Achieve frame sync in UE4's parallel rendering

Development Programming & Scripting C++
1

Hi!

I’m trying to sync gamethread and drawing thread(RHI thread/rendering thread) , i.e. I want to have updated graphic information before I start next frame and I would like to know when a frame ends as well.

After reading several posts, mainly Low Latency Frame Syncing | Unreal Engine Documentation, it lead me to r.GTSyncType 1 and r.OneFrameThreadLag 0 if you want to get this done.

Is this the right way to go about it? Also, how do I get notified at the end of a frame(after the sync)? I’m not able to find any events to register to.

Cheers!

2

Im pretty sure thats to lower vsync lag, not that you should have vsync on anyways.

3

Maybe, but with r.Vsync 0, we can get rid of vsync.
But, r.OneFrameThreadLag says that if it is set to 1 (which is default), you get 1 frame lag, else complete sync. If this is true, why do we need r.GTSyncType and how are these related?