Dxvk: F.R.: Demon Stone - opening sequence glitches

[WinterSnowfall]

Right at the start of a new game, during the in-engine opening intro sequence, the camera passes through the main character and then he seems to move in slow motion for a while. Everything gets back to normal once you briefly see an orc running in the background.

Other in-engine sequences may be affected, though I haven't seen anything similar during gameplay.

Initially, I thought this was a Wine issue, but it doesn't happen with WineD3D.

Here's what I've recorded (sorry for the frame-skips, but it's the best my modest quad-core can do apparently):

Intro sequence with DXVK
Intro sequence with WineD3D

Software information

Forgotten Realms: Demon Stone (GOG version).

System information

• GPU: GeForce GTX 1070
• Driver: 440.48.2
• Wine version: 5.1 Staging
• DXVK version: v1.5.4

Apitrace file(s)

This part is already captured in the API traces provided with #1409

Log files

• d3d9.log: demonstone_d3d9.log
• d3d11.log: N/A
• dxgi.log: N/A

[WinterSnowfall]

I see this was reported before as part of issue #321 on d9vk. CartoonFan has a better capture of the slow-down in his last comment.

[doitsujin]

Have you tried enabling vsync? This sounds like the kind of thing that happens when games run at higher frame rates than they are designed for.

In any case, this is almost certainly not a bug on our end.

[WinterSnowfall]

Have you tried enabling vsync? This sounds like the kind of thing that happens when games run at higher frame rates than they are designed for.

Right on the money, once again :). I'll keep it in mind if I see anything similar from now on.

In any case, this is almost certainly not a bug on our end.

There's no game option for v-sync, but setting d3d9.presentInterval = 1 in dxvk.conf fixes the issue. Can this be added as a game-specific workaround?

[NerosTie]

It looks ok on my side:
https://imgur.com/a/WIbk5OS

[doitsujin]

I don't really like the idea of force-enabling vsync since the results depend on each user's monitor. But then again we don't have any other FPS limiter at the moment.

Would be interesting to know at which frame rate it starts breaking, if it's 200 FPS or less then we definitely need something else since high refresh rate monitors might start running into the issue otherwise.

[NerosTie]

This is the FPS limiter I use for Vulkan applications:
https://github.com/pchome/VkGHL

[WinterSnowfall]

I don't really like the idea of force-enabling vsync since the results depend on each user's monitor. But then again we don't have any other FPS limiter at the moment.

On second thought, I agree and take back my suggestion. Since it won't affect everyone it shouldn't be considered as a workaround.

However, an entry in the Common-isues section of the wiki for high refresh-rate problems in general (while not DXVK specific) would be useful for people running into these sort of things and not knowing what they are or how they can be fixed. I would still be one of them if not for the feedback you've provided on this thread.

That being said, I'm quite happy I've figured out one of the last things preventing me from playing this game, so I'm closing this "bug" :). Thanks again for all your inputs.