Question [Case 1201827] HDRP 7.1.6 PBR Sky: Simple rotation of Direction light consumes 80 ms of CPU

Empty scene, only PBR Sky and script that rotates Directional light every frame. And I get 12 FPS. It was not the case in the 7.1.5 Any suggestions?

 

Yea, same for me as I mentioned in the pbs feedback thread;

Hopefully this get fixed soon.

 

I doubt that has something to do with the update method of Pbr sky setting and the sample rate, the slider in the setting can go up to 10. There is also a setting to make the sky static or dynamic. That all could have an influence.

 

If I do not rotate the light everything is ok.

 

If the directional light does not change, the pbr sky have not to be updated. There is an update method setting for the pbr sky. On changed, on demand or always. So updating could be very expensive.

Hopefully in the future, that will be accounted with a new Realtime GI solution by Unity ...

 

No it shouldn't be, because it partially based on Bruneton atmospheric scattering and precomputes sky for all light and view directions. It may be connected with rendering ambient and reflection probes, but even with On Demand option selected it performed terrible. And as I mentioned above it was not the case in 7.1.5 and earlier versions. So something is broken very hard.

 

For me it was before 7.15 also. Anything I change in PBS sky setting results in editor freeze till update.
https://forum.unity.com/threads/physically-based-sky-sun.768977/#post-5120810

 

How to get HDRP version 7.1.6? I'm using the beta but the package update did not show update.

 

You need 2019.3.0f1 It is not available in unity hub, so you need to download it directly from unity site.

 

Why not in Unity Hub? Because it is to unstable?

 

Looks like it doesn't bound to the PBR Sky. I've disabled volume profile with it, and it still consumes 80ms when rotating light.

 

Is it only related to the rotation or also other attributes of the directional light?

 

Not for me though, it only happens with an active pbs, works perfectly fine without it.

It happens with everything that somehow effects the pbs, so directional light parameters and the pbs settings itself ofc.

Setting the Ambient Mode to Static gives an extra performance boost, reducing the Number Of Bounces also helps a bit, however it is still way slower as it used to be. Using the realtime update mode with a long update period shows no real advantage either. We're kind of stuck here.

 

I think final HDRP version will be 7.2.0 so there is advancement coming.

 

The scary thing is that 7.1.6 is marked as 2019.3-verified

 

Release is in 2 weeks so they have time to fix it.

 

Are you sure the performence cost is not by architecture? Maybe comparing the the new sky shader with the old one that was more stable.

 

Has this been fixed? SSAO showing on wrong screens

 

Latest 7.1.5

 

The report bug tool crashes and I won't spend more time on it. Good luck finding the problem!.

 

Saw the PR that fixes PBR Sky issue. That is great news! Thank you.

 

Seems the massive performance hit has been fixed in 7.1.7