VR Forward Rendering shadow performance

Development Platform & Builds XR Development
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1

Hey, I was wanting some performance/profiling help & understanding.
I have a bunch of non-shadow casting lights (doesn’t matter if they’re stationary, static or movable), and each light seems to be costing performance based upon if I have any other shadow casting lights in the scene.

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In the GPU profiler (see above) there’s a lot of CopyToResolveTarget(ShadowMaskTexture->ShadowMaskTexture) events inside of ShadowProjectionOnOpaque.
Each one is 0.07 ms (which does scale based upon the screensize), and I have one of them for every (non-shadowcasting) light in the scene
Many of these lights will be controlled on & off as a group, and was wondering if one option is to use lighting scenarios, and flip between them, but having static lights through lighting scenarios still incurred the same cost
If multiple stationary lights counted as one that could cut down on the number, and increase performance
I haven’t seen any other way of affecting the number of these events or the length of time they take to happen
I’m using the forward renderer & VR
Having the lights not render using max draw distance also seems to not reduce the number of these events
My end goal is having light switches that can turn groups of these lights on and off, so far haven’t been able to work out how to improve this performance

Any help is apprecated

Thanks

2

I am experiencing this problem aswell. When i built it with static lighting then the performance drop disapeared.

3

Yeah, if the shadowed light becomes static the performance drop disappeared, but I need it to be static

Or do you mean something different?

4

Same problem, I moved my 2 VR projects from 4.25 to 4.26, and the performance goes crazy drop, in the gpu profiler have the same CopyToResolveTarget(ShadowMaskTexture->ShadowMaskTexture).
I don’t have this problem in 4.25, what changed in 4.26 ???
I really need help on this issue. The only thing that I find out that gives-me back the FPS is disabling the LigthSource, if I turn it off the performance goes back to the same FPS as the 4.25

5

I’m using te MSAA method. do need to change? Thx

6

Yes, i did try to switch to the other method’s and the problem of the FPS drop is gone. Seems the MSAA method is broken in 4.26

7

I’ve switched the antialiasing method and the problem disapeared. The forward shader seams to have problems with the standard AA method.