Another Unreal Game, another Shader Cache #StutterStruggle

[monotony]

Sigh, I'm getting really tired of this. At the start of the demo, every time a new and bigger area is loaded in and whenever an effect is drawn for the first time: There is a stutter.

Please implement a shader compilation pre-step for the final game.

[Chozabu]

Hey, thanks for the heads up on encountering some stuttering!

I suspect the cause may be related to either the camera or some types of particle system, shader compilation shouldn't be the cause, as we are on dx11, with all shaders pre-compiled - but I think shader cache became an issue with dx12?

Could you let me know your specs? and if possible record a video - can be really handy in diagnosing these things.

I'll have a read up on if there could be an issue with dx11 shaders, and look over the more suspect areas of Europa meanwhile.

[monotony]

Man, the game being on DX11 totally passed me by, I'm sorry for that. However, as far as I know, shader compilation still happens under DX11, just on the driver level. No such thing as pre-compiled shaders on DirectX unless you're running fixed hardware like the Steam Deck.

Specs: i9-10900k, RTX 3080 10GB, 32GB DDR4-3600
I'm running the demo with Vsync off and the in-game frame limiter enabled on a VRR display.

Here's a video of the start of the demo with a cold shader cache. You can see the frame time graph spiking at the first foot steps, the first jump, glide and the first power-jump. Some stutters are more noticable than others, mind you. And I bet many players won't notice them at all. I've learned that much.

https://www.youtube.com/watch?v=iBGIkNxXl0Y

It's even more pronounced with water splash effects:

https://www.youtube.com/watch?v=xnoX9AcAdXk

Restarting the demo and running these segments again doesn't cause the same stutters, which is why I still suspect shader compilation to be the issue.

[Chozabu]

Nice videos! i see what you mean - those do indeed look like shader stutter

I'm having trouble replicating stutter though - What method are you using to clear your shader cache (or otherwise cold-start?)

[monotony]

I've deleted the contents of

...\AppData\LocalLow\NVIDIA\PerDriverVersion\

Skipped everything that cannot be deleted.

I could've also cleaned the Nvidia folder in %localappdata% or cleared the DirectX Shader Cache via Windows Disc Cleanup but that doesn't seem be needed. Disabling/re-enabling Shader Cache Size in the NVCP before and after.

Now thinking about it, the issue could of course be driver related, too. I'm on 551.86 still. Probably should update those.

[Chozabu]

Fantastic! Removing the files in

 ...\AppData\LocalLow\NVIDIA\PerDriverVersion\ 

did the trick, I should now be able to test possible fixes :)

Most of the things I've read to do with handling this are related to ue5/dx12. If there's not a sensible way to fix it, I may be able to do some sort of workaround like firing off all effects in the level right between streaming it in and the camera fade... but hope to find a simpler solution.

Thanks again for the report, details and extra info! Will hopefully post here soon with an update

[Chozabu]

Originally posted by monotony:

Please implement a shader compilation pre-step for the final game.

OK! We should now have shader pre-compilation. I enabled some engine settings to handle a good deal of in-level shaders, but didn't find a working automated method to handle spawned effects that worked with our toolset, ended up manually listing these for Ue to pre-compile.

Surprised I didn't find a more normal way to handle this, I can see why it's an issue in so many games - though hopefully wont be in Europa anymore, or in newer UE5 games which have a more supported path for shader precompile.

you may be able to avoid a good deal of stutter in other ue4 games by adding these to the games user config (often something like "%localappdata%\GAMENAME\Saved\Config\WindowsNoEditor\Engine.ini" )

[/script/engine.renderersettings]
r.CreateShadersOnLoad=1
niagara.CreateShadersOnLoad=1

Will likely help with large areas and regular shaders, but not likely to help with spawned effects

[[HP]]

Thanks so much rising awareness to this! 🙏

[monotony]

Thank you very much for reacting this fast and friendly, despite my tone. I didn't expect this to be such a pleasant interaction.

[[HP]]

Originally posted by monotony:

Thank you very much for reacting this fast and friendly, despite my tone. I didn't expect this to be such a pleasant interaction.

No, thank you!

I've just pushed a demo update, so this issue should be fixed in the demo and in the full game when it's released in a couple of weeks!

[Orion1189]

Just wanted to comment, as someone who is *extremely* sensitive to stutter and any minor variation in framerate, after playing through the demo, I can say that I experienced absolutely no issues whatsoever. Genuinely a perfectly smooth and consistent experience, at 1440p and max settings. Barely even used any CPU or GPU to do so either, and on a relatively old system to boot. Very impressed with the optimization in general, and especially for a modern UE game.

[Jedimindtrickonyou]

It’s awesome seeing developers being receptive to making the game (and demo) better and getting rid of stutter. Definitely want to support the game even more now after playing the demo on both Switch and Steam Deck.

[ChubbiChibbai]

Originally posted by Orion1189:

Just wanted to comment, as someone who is *extremely* sensitive to stutter and any minor variation in framerate, after playing through the demo, I can say that I experienced absolutely no issues whatsoever. Genuinely a perfectly smooth and consistent experience, at 1440p and max settings. Barely even used any CPU or GPU to do so either, and on a relatively old system to boot. Very impressed with the optimization in general, and especially for a modern UE game.

What hardware are you running on?

[Orion1189]

Originally posted by ChubbiChibbai:

Originally posted by Orion1189:

Just wanted to comment, as someone who is *extremely* sensitive to stutter and any minor variation in framerate, after playing through the demo, I can say that I experienced absolutely no issues whatsoever. Genuinely a perfectly smooth and consistent experience, at 1440p and max settings. Barely even used any CPU or GPU to do so either, and on a relatively old system to boot. Very impressed with the optimization in general, and especially for a modern UE game.

What hardware are you running on?

RTX 2080, i7 4790k, 16GB RAM. Most games still run well enough, but it's some relatively ancient hardware by modern standards, and the game barely taxes it at all. If the full version is as well-optimized as the demo, it'll likely run well on a wide range of hardware.