Input lag with unreal engine 4 titles

[jjmaxie0302]

Is there anyway you guys diminish this problem, or any Tips you have to make it less impactuful? I find that I miss a lot of good moments in games because if this even after waiting the recommended 15 minutes

[Bo3b]

Please give me more context here? I'm not sure what your seeing.

The term "Input lag" is almost always used to refer to controls lagging behind what you see on the screen. And is often because frames are buffered. So a triple-buffered game is described as having input lag because your inputs are three frames behind.

Using that definition, I don't think there should be anything that we change relative to how games work. If you set it to no vsync, single buffer, I'd expect you to get 1:1 frames for every frame you can see in VR. Assuming you can run a full 90 fps and turn off our frame rate limit.


I don't understand what you mean by 15 minutes. There should be no need to wait for any UE4 game.

[jjmaxie0302]

On the helix mod webisite I will send you what it says for most unreal engine 4 profiles .




2. Starting the Game and Ingame-Setup:
- START the game via 3DFM, or via launcher/shortcut/game-executable
you may need to wait up to 15 min if you run the game for the first time!
The game may have HUGE INPUT LAGS the first time and while loading (NEW) areas (because of shader caching) ....its getting better the more you play.



This was copy and pasted from little nightmares 2 on the site . Do that was what I was referring too cause I did experience input lag but it did get better as I went on but in new areas it came back .

[masterotaku]

Input lag is a bad description there. It's all about regex and its shader cache generation.

The UE4 universal fix (used in many UE4 fixes) has A LOT of regex blocks that try to fix the game automatically, without needing to dump and fix shaders manually. Every shader in the game needs to be checked against those regexes to see if they need to be modified and replaced. The result of this operation is saved in the "ShaderCache" folder where the game exe is.

The next time (like a new session) that the game tries to load a shader that already passed that process will load instantaneously.

The 15 minutes number would be just an estimate of a game having most of its shaders common to most parts of the game. But the stutters and stalls can be really annoying the first time you see new effects.

More regexes = more stutters the first time new shaders load. No solution other than dealing with it. Having the game in an SSD can make a big difference (an external HDD is really bad).

[Bo3b]

Ah, OK I see. As masterotaku notes this would not be described as input lag, a more accurate description is 'stuttering'. English is not Losti's native language, so it can be hard for him to translate some things.

The 15 minutes that Losti writes about there is actually only for the first launch, where you might have a locked-up black screen for the game while it busily works through shaders and caches them. On most games it's less, maybe 1 minute where you get no response from the game.


@masterotaku: Do you happen to have a complete shader cache for any UE4 game?

One thing we could do to improve this would be to ship a full shadercache folder as part of the universal fix. It won't catch everything because of game variance, but would be a good starting spot to avoid the startup hang and the vast majority of the regex stutters.

PaulDusler has updated a couple of game fixes with shadercaches he has lying around, but for game engines like UE4 and Unity games, we could also add another shadercache download that tries to be more comprehensive. Versions would not necessarily matter because any cached shader that doesn't match the hash would be skipped.

[masterotaku]

Originally posted by Bo3b:

@masterotaku: Do you happen to have a complete shader cache for any UE4 game?

No. Coincidentally, I rarely played any UE4 games lately. And the games I fixed used the older DHR UE4 universal fix as the base, which had a lot less regexes and stutters.

[Bo3b]

Originally posted by masterotaku:

Originally posted by Bo3b:

@masterotaku: Do you happen to have a complete shader cache for any UE4 game?

No. Coincidentally, I rarely played any UE4 games lately. And the games I fixed used the older DHR UE4 universal fix as the base, which had a lot less regexes and stutters.

OK, thanks for the info. We'll work out some way to get a sort of superset of cached shaders to help with this problem.

When you make new fixes, it is probably worth adding your shadercache to your fixes. I know we historically have not done this, but it seems like it's worth adding. Only real drawback is larger fix files, and that will be fine.

[Bo3b]

Originally posted by jjmaxie0302:

Is there anyway you guys diminish this problem, or any Tips you have to make it less impactuful? I find that I miss a lot of good moments in games because if this even after waiting the recommended 15 minutes

Here is a bit of an experimental ShaderCache folder for you to try. This is just a cache of shaders from 7 games I've got on my system that are pretty complete caches. We don't know if these will match your game, but might help.

https://duselpaul86.s3.amazonaws.com/UE4_Universal_Fix/UE4_ShaderCache.7z

Unzip the ShaderCache folder in the archive into the game root next to the game exe and the ShaderFixes folder. You probably already have a ShaderCache folder, and if so, merge them. Keep your original files for any conflicts.

[jjmaxie0302]

Nice so my best bet would be just to touch it out then like I said it wasent that bad anyway I still enjoyed the heck out of little nightmares 2 I even decided to use you guys over vorpX just of off the fact of the sharp visuals and the care that goes into the unreal fixes I didn’t notice any shadow glitches or anything with the fix
As with vorpX there wasent any slow downs but there was annoying visual shadow glitching.

[jjmaxie0302]

Tough*