Texture update latency

anonymous_user_9e8de314 · February 27, 2015, 12:38am

I have noticed there is a texture update latency in Unreal. In my rtsp media streaming decoder plugin from live camera feed I get about 220ms latency in Unreal where in my example opengl render i get about 120ms latency in texture update.

Is there a way to tweak the texture update rate in Unreal Engine?

The attached image shows my latency test. Hardware used: Asus Monitor 120Hz, Canon Rebel T3i camera, GoPro4 camera, Teradek Cube 205 video encoder.

Actual time is 1:45:65
My OpenGL renderer shows 1:45:53 = 120ms latency
Unreal shows 1:45:43 = 220ms latency

I did multiple takes and unreal is constantly 100ms slower then my OpenGL renderer

anonymous_user_2b03d27c · February 27, 2015, 7:34pm

Hey -

I moved your post to the Rendering section so that it will get more visibility and traction.

Pjotr · February 27, 2015, 8:42pm

As I understand unreal engine queues up rendering commands and calls them on a separate thread. This can get behind on the main thread. You could call FinishCurrentFrame every frame to make sure the thread does not stay behind too much but that would probably have a negative impact on the performance. Another thing that can decrease latency is setting r.FinishCurrentFrame to 1. But that will also decrease performance.