Game slightly tears, despite vsync being enabled

Forum rules
Please don't bump threads here if you have a problem - it will often be forgotten about if you do. Instead, make a new thread here.

Post a reply

Smilies
:D :) :( :o :shock: :? 8-) :lol: :x :P :oops: :cry: :evil: :twisted: :roll: :wink: :geek: :ugeek: :!: :?: :idea: :arrow: :| :mrgreen: :3: :wub: >:( :blergh:
View more smilies

BBCode is OFF
Smilies are ON

Topic review
   

Expand view Topic review: Game slightly tears, despite vsync being enabled

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Thu Nov 01, 2018 12:39 pm

cool. Then I dont have to force it by nvidia driver anymore :P

But wouldnt it have been simpler if it would be like this in the menu?

Vsync Mode: Off | Adaptive | On

instead of this hidden console cvar?


Else I would at least rename the vsync option in menu to
Adaptive Vsync : On | Off
Because if I read
Vsync: On | Off
I expect it to be a real vsync and not adaptive.

Adaptive is in my case terrible. The switch between vsync on and off inbetween adaptive vsync has a likelihood of a slight stutter while this happens (at least this was the case with Blood 2)
and
like I mentioned already in this thread I got a teared videocapture due to it. With a capture card it must be permanent vsync.

like said:
Vsync Mode: Off | Adaptive | On

Would make to me the most sense. What do you think about this?

Re: Game slightly tears, despite vsync being enabled

by Graf Zahl » Thu Nov 01, 2018 4:12 am

This has been addressed some time ago: set gl_control_tear to 0 and adaptive VSync will be disabled.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 7:37 pm

ohhhh okay if it is just adaptive it explains everything.
Yes then I would be very happy if you could make it so that I can have a permanent vsync. Also permanent vsync runs for some reason more smooth for me too. The forth and back switching from vsync on and off causes for me more fps swap/stuttering than a permanent vsync for me does.

Re: Game slightly tears, despite vsync being enabled

by dpJudas » Sat Dec 30, 2017 7:24 pm

Yes, it is using adaptive vsync if the OpenGL driver supports it. There's currently no option to disable that behavior, but of course we could make vid_vsync into a three-state thing: 0 = off, 1 = adaptive, 2 = always.

As for triple buffering, not worth the problems involved in supporting it. Right now GZDoom does a glFinish after swapping the buffers. If that glFinish is commented out all kinds of visual artifacts appear, probably due to the way the pinned VBO is being filled.

Note: I didn't add the feature to GZDoom, so I don't know when it was introduced.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 7:13 pm

So the game is using adaptive vsync and not permanent vsync?
That would explain the tearing then if it is like this.

But then it really should be called the same in options of the game and also should be a seperate option. If I see vsync I expected a permanent vsync and not adaptive (and it is permanent vsync in zandronum and gzdoom 2) (at least my observation. Sorry if incorrect ;D )
Triple Buffering : I didnt request to add it :) And if so it of course would have to be optional too with default being off. But if it is adaptive vsync, Triple Buffering wouldnt avoid the tearing either ;D
But I personally definitely need a permanent vsync. Otherwise I cant capture videos without tearing. Or I must use the nvidia control panel vsync. But I think the game should be able to do it as well, shouldnt it?

Re: Game slightly tears, despite vsync being enabled

by dpJudas » Sat Dec 30, 2017 7:04 pm

I guarantee you that if I forced triple buffering in GZDoom people would be complaining instantly about the mouse lag. With 120 hz the latency is half, of course, but ultimately it doesn't fix the problem Chris was talking about. If a game is unable to maintain the desired frame rate, then, unless its due to some resource load problem, it will continue to miss the deadline for many frames - the triple buffers will therefore end up empty as the game/GPU can't keep up.

If it gives some compatibility problem with some software we can of course make an option for disabling adaptive vsync.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 6:46 pm

The setting in Nvidia controls it on/off for Direct3D though - also games. Just OpenGL and Vulkan not.
Honestly with 60hz it didnt make much of a difference for me with 1 or 2 prerendered frames. 60hz vsync is in both cases - on or off awful, inacceptable input xDDD
And with 120hz it doesnt make a difference to me either. Thats high enough to have almost no perceptible input delay by vsync, no matter if Triple is on or off. For me at least no difference.

Re: Game slightly tears, despite vsync being enabled

by dpJudas » Sat Dec 30, 2017 6:36 pm

Only video playback uses triple buffering. The mouse lag you get from queuing that many buffers is unacceptable for most games.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 6:22 pm

Depends. Some people would prefer a bit of tearing to maintain a high FPS rate, rather than cutting the FPS in half because a frame was a few milliseconds late.
fractional fps changes are normally avoided by using Triple Buffering. I dont know if GZDoom is using it. The setting in nvidia has just influence to Direct3D.

Re: Game slightly tears, despite vsync being enabled

by Chris » Sat Dec 30, 2017 6:15 pm

XxMiltenXx wrote:And even if the FPS fall behind, VSync should then use the next lower fraction, in this case 60FPS in his case or 72 in my case.
Depends. Some people would prefer a bit of tearing to maintain a high FPS rate, rather than cutting the FPS in half because a frame was a few milliseconds late.
Kotti wrote:If this is the same as WGL_EXT_swap_control_tear then it is being used.
Yes. There's a GLX equivalent also that SDL may use (the SDL GL code doesn't seem to check for the extension though; if vsync is wanted it just tries to set a swap interval of -1 regardless, and if that fails falls back to 1). This certainly seems like the kind of thing that could be toggled with a cvar.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 4:11 pm

De-M-oN is on Windows 10.
No I use Windows 7. But I think it was a typo, because you normally know it^^
I think 112 in his case is visible, because he has such an high update rate for his FPS counter.
It is because of project brutality being very ressource intensive, but that shouldnt have any influence to tearing, also you jonath, you play the vanilla game and there it is the same.
Also Complex Doom is often ressource intensive and with zandronum this doesnt happen either. Just to clarify that.

I will later try out what happens if I force vsync on in nvidia control panel instead the game. But even if that helps - then even more we know that the game's vsync is apparently something wrong with. I'll update as soon as I tested it.

Re: Game slightly tears, despite vsync being enabled

by Kotti » Sat Dec 30, 2017 3:59 pm

Chris wrote: Is it possible adaptive sync is being used?

If this is the same as WGL_EXT_swap_control_tear then it is being used.

Re: Game slightly tears, despite vsync being enabled

by XxMiltenXx » Sat Dec 30, 2017 3:54 pm

I am on Windows 10, De-M-oN is on Windows 7.

I am not aware of a setting for adaptive Sync in GZDoom, in my NVidia control panel it is set to "Application Controlled".

And even if the FPS fall behind, VSync should then use the next lower fraction, in this case 60FPS in his case or 72 in my case. I think 112 in his case is visible, because he has such an high update rate for his FPS counter.

Re: Game slightly tears, despite vsync being enabled

by Chris » Sat Dec 30, 2017 2:44 pm

What OS?

Is it possible adaptive sync is being used? Not sure if there's a specific setting/cvar for it in GZDoom, but if it's being used the card will vsync as long as its "on time", but if a frame happens to be late it will exhibit tearing instead of waiting for the next refresh. The first screenshot does show an fps of 112 rather than 120, indicating it fell behind.

Re: Game slightly tears, despite vsync being enabled

by De-M-oN » Sat Dec 30, 2017 1:31 pm

rare is the massive tear like our 2 posted screenshots. But slightly teared frames we have less enough to mostly not notice it while running video/game, but often enough that it is not so nice to have on a youtube video.
So at least it is for me.

Top