[VR] stat gpu = 40% composition PreLighting ?

I’m looking at ways to improve an Oculus archviz scene. Its a house; an interior with surrounding landscape. I set a fixed frame rate of 90 but the fps is 45 most of the time.
Looking at the profiler data, the cpu is waiting 22ms for the gpu. Stat gpu reveals that almost 40% (8ms) is used by ‘composition PreLighting’.

Anyone has an idea what this is and what I should be looking for to improve this ‘composition PreLighting’? I already searched Google, this forum and the Answerhub.

My guess was ‘dynamic lights’ but I changed those (one lightsource for the sun and one skylight) already to static.
Using 4.15.1 & deferred renderer.

I’m curious about the ‘composition PreLighting’ in stat gpu, although not specifically for vr. I’m also a bit curious about the [Unaccounted] item in stat gpu as well.

bump dat the question. Have the same problem. PreLighting takes about 2 ms, what can cause it? and how can I reduce the impact of this :frowning:

Do you have Ambient Occlusion turned on?

in world settings for lightmass? nope , checkbox turned off

Can you try to add a post-processing volume, make it unbound and turn off all AO related settings?

i selected existing PP volume and turned off all AO settings or disable whole PP - comp prelighting goes down by half - from 2 to 0.9ms. But where is another 0.9 ?

whooops - sorry. In project settings=>rendering=>default settings AO was still active. turned this off down Prelight value to 0.00 :slight_smile:

And another question - what difference in AO and AO static fraction

I believe the tooltip in the Project Settings is pretty clear. It enables AO for baked lights.