Is Simugraph The Root Of The Issues?

Playing a bit of SimRail last night, which has just come out of early access, performance was a bit stuttery and juddery in places. However one thing it did not do was induce the horrible sound squelching and distortion which seems to have become the norm in TSW5. That is making anything with smooth traction sounds, particularly the new Class 87 on WCMLoS, almost unplayable. But on SimRail, both the EP07 electric loco and EN57 didn’t miss a beat where the traction sounds are concerned.

So why then does TSW screw up the sounds so badly when it stutters? Well the finger has to point at Simugraph. We know from what we were told about the WCL Class 150, that the sounds are intrinsically linked to the physics output. By binding the sounds to complex physics iterations has this in turn resulted in the very poor sound we are now getting? A further example is steam traction where the fine nuances of the exhaust chuff blur into a wall of white sound, above about 35 or 40 MPH.

I haven’t tried the steam locos in SimRail yet, but will make a small 20p side bet, if I can get that up to around 50 MPH, the sounds will still be clearly audible.

Thoughts?

 

The elephant in the room Vern I’m afraid is hardware. If I get these sound stutters they are so occasional they’re barely noticeable, and bear in mind I don’t have the latest and greatest. This, I believe, is also a UE4 issue unfortunately and the more hardware you throw at it the better. ‘Twas always thus.

 

Except… PS5 is suffering the same issue which has standardised hardware components.

 

Have to say, I recently got a gaming rig with a 4090 and I haven’t experienced any sound issues on Shap, even with the expected microstutters of UE4.

I’m playing with a vanilla game install with every DLC, zero mods.

 

I'm getting it on WCML Shap but can't say I'm experiencing it on other routes.

 

In TSW or SimRail Matt?

If the former, it’s evident to some extent on the preview stream that was done.

I think it notices more when you have smooth traction sounds rather than running diesel, when I did a 47 hauled run not so evident. But then there may be more physics work going on with the 87.

 

SimRail is built on the Unity game engine, TSW on Unreal Engine.

The thing I do not understand, is that when I drive at 150mph in Forza Horizon, or my truck in ETS, that there are zero stutters. Infact the luscious environment of Avatar Frontiers of Pandora while flying through the air never drops a beat at 4K.

How do these games load/unload assets without the horrible stutters and frame drops we see throughout every version of TSW ?

 

I think the sounds definetly have to do with simmugraph. Thats where the high pitched noises come during microstutters.

But: compared to people say wcmlos is unplayable, my pc run both routes very well (same for blackpool branches). Its far from unplayable, instead i can call it enjoyable as it should be. (Not free from stutters, but very fluent mostly)

Yes with the 3 new tsw 5 core routes, the first time in tsw i noticed an fps drop. Still its far from unplayable. Im wondering if the new feature (guardmode + 2d map) might eat the entire performance. Cant immagine what changed else which would cause that. Suspension physics maybe?

But if the 87 is unplayable, your hardware might not keep up with all that?

Pulling a 2500ton train uphill with a single class 08. Thats when your hardware is struggling with the situation.

 

Unplayable was perhaps an exaggeration, but certainly not optimum listening experience. Anyhow next time I do a run I’ll try to capture the sound distortion albeit my only recording software is the built in Windows Gamebar. And the hardware is a bit of a myth. I’ve had sound glitches on SEHS on the PS5 withTSW5 and while freely admitting my PC is a potato, no other game mangles the sound in that way.

 

That was too obvious running the Class 66 on WCMLS, for me unplayable, as Audio is very important. My understanding is the sound output is directly tied to a module that when stutters occur, is also halting the sound calculation but not the output (separate thread?), leading to the frequency dropping. Very apparent on high pitch Class 87, less noticeable naturally on low frequencies.

Why Matt hasn't noticed it I do not know. Maybe it's not appearing on dedicated sound cards, which are probably not in use very widely any more. I think we're all listening to RealTek onboard sound these days unless you're producing music with your PC.

 

But no other game is necessarily as demanding…

 

Begs the question why the heck it's that demanding. We know initially when CSX:HH came out they were not using rolling stock LODs, which has long been sorted.

The scenery is not something you'd say "Wow", many objects are far less detailed than in other games, especially low-LOD distant scenery in TSW5 (for comparison, AP are using highest LODs up to 1000m distance for their trees and let the hardware scale them, that's why vegetation looks so much better in current TSC routes - In TSW you can only look at trees when stationary. Even Frankfurt skyline uses higher res textures (albeit not the correct ones everywhere) in TSC). Play Forza Horizon and you think "how the hell did they achieve this" with all the added water and dirt effects and high speed rendering. Of course, not wanting to sound dismissive, that was done by premier league coders.

SimRail visuals are sharp as a knife even at 100% TAA scaling, probably an advantage of Unity (which imho is the better engine in many ways.)

On my last venture into TSW I decided to dump DX12 and all ini changes, only foliage scale 3x, and I found it to be performing better under DX11 than with all these DX12 tweaks which are now actively discouraged by DTG, probably for good reasons. Of course, having a strong CPU helps here.

I'm also not permanently chasing the latest GPU drivers as I do not think there's any development affecting UE4 games, which are pretty much optimised and finished on driver side, any more in these drivers.

 

While I do have some experience working with Simugraph, I'm not an engineer at DTG so take what I write with a grain of salt. With that said, I am very skeptical about sound hitches or stutters being due to Simugraph. Unless you are driving extremely long trains, Simugraph is not that demanding, and if you were to drive such a long train then I would expect the FPS to drop (to be clear I have never experienced this, but my PC is quite powerful) rather than stutters to occur.

From my experience the sound hitches are due to the typical "UE stutters" from tile loading/world origin rebasing (UE transforming the coordinates iirc) and if the sound cue is a loop it may pause. Interestingly one-shots do not suffer from this issue (things like button clicks or basically anything that has a finite duration).

 

Spikee
I can say it does happen to a lesser amount of sound card AE5 creative than built in related,or related as a example.
Run the 87 on wcml south and ecml.
The problem Vern highlighted is more pronounced on Preston to Carlisle than the two other routes.And non existent on current version gwe.
The stutter on Preston appears as the next tile for scenery loads That's sound stutter.
GWE has zero sound stutters,if that's any help.
From a personal observation, Preston to Carlisle has got more sound stutter than earlier runs on the route.So I've not been on it, expecting optimisation in a patch.
With a Ryzen 3600, I'm running relatively old hardware;32 gig ram, 2070 super and gpu driver for physics is set to hardware rather than automatic.
Onboard realtek and the gpu sound are disabled in Windows 10.
I know you are a modder Spikee.
Not very technical with modern hardware, hope it helps.
Apologies for the janky edit, hands today feel like someone else's.

 

I've seen you mention this a few times but I can say that on PS5 at least I have no noticeably audio issues, even on routes where performance dips below 30 fps and there are graphical stutters the sounds are normal to me.

 

I haven't run into anything other than the "normal" UE stutters on PC or Xbox Series X.