Objects vibrating, issue 2737?

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raevol
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Objects vibrating, issue 2737?

Post by raevol » 13 Dec 2015, 03:06

Scrawl, I'm seeing https://bugs.openmw.org/issues/2737 now that my fps is good enough to see it. :D Is this something we will be able to fix? Have we hit a limitation with our engine we won't be able to overcome? Or is it doable?

Chris
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Re: Objects vibrating, issue 2737?

Post by Chris » 13 Dec 2015, 04:37

It's fixable (sort of) by working properly within the Bullet framework. Basically, letting Bullet control the position of physics objects which will run it at a specific rate and interpolates when in between those frames, so it moves more than 60fps. Last I tried it, it ended up performing a lot worse, but I also didn't really know what I was doing.

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raevol
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Re: Objects vibrating, issue 2737?

Post by raevol » 05 Jan 2016, 07:21

Sorry to be a continual pain in the ass, but can I bump this?

aesylwinn
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Re: Objects vibrating, issue 2737?

Post by aesylwinn » 11 Feb 2016, 02:38

I took a quick look at this. One of the things that recently went away with the osg upgrade was the use of bullet for simulation. Now bullet is only used for collision detection only, which takes away the option to interpolate with bullet.

Personally, I think that with the current code the problem is from something not being properly kept up to date between the physics and rendering systems. Specifically, something that is updated with the movement/animations in the actors class for MWMechanics (though the actual issue might be elsewhere) since I was able to reduce the the amount of jittering by forcing that part of the engine to update at the same rate as my vsynced framerate.

Anyway, as a quick workaround, I believe that the problem cannot be seen if you disable vsync. Can anyone else confirm this? I went from almost seeing double to only some jerky movement which probably comes from the character controller and its collision solver. With vsync I was at 60 fps, without it I was between 180 to 330 fps depending on where I looked.

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raevol
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Re: Objects vibrating, issue 2737?

Post by raevol » 11 Feb 2016, 08:35

I definitely still see it with vsync off. Let me know if I can be more specific in any way...

aesylwinn
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Re: Objects vibrating, issue 2737?

Post by aesylwinn » 11 Feb 2016, 23:52

Just to be clear, I won't be devoting to much time to this right away since I already have a task I'm working on currently.
It seems I originally found a different bug (or at least it looks like it), but I think I found the right one now. It would be useful if you could answer the following questions so I can narrow down the conditions and make sure I'm on the same page.

What framerate are you getting? (F3 in game should display fps)
In terms of magnitude, is the vibration slight or obnoxious?
Does it matter if you are very close (almost touching) to the object when it vibrates, at arms length, or farther?
Are you seeing the vibration only when making a turn, or can you also see it while moving in a straight direction?

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Lagahan
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Re: Objects vibrating, issue 2737?

Post by Lagahan » 12 Feb 2016, 04:23

aesylwinn wrote: What framerate are you getting? (F3 in game should display fps)
In terms of magnitude, is the vibration slight or obnoxious?
Does it matter if you are very close (almost touching) to the object when it vibrates, at arms length, or farther?
Are you seeing the vibration only when making a turn, or can you also see it while moving in a straight direction?
Assuming this is the same issue as 2737, the latest build I have (scrawls cell preloading one) the vibrating behavior is the same as the video I posted in the comments on the bugtracker on 0.37.

Pretty much only vibration when the player character is moving, camera is smooth. Very obnoxious on 120hz, much less so on 60hz. With uncapped framerate varying up and down it seems more pronounced than if its a steadier framerate. Worsens the lower the framerate gets. Happens moving airborne, in water, on statics and on land so it doesn't seem to be collision with objects doing it.

I nearly constantly get over 120fps in most situations with the water shader off, but with it on it varies between 40 and low 100s.
Specs: Core i7 8700k @5GHz, EVGA GTX2080ti XC SLI,
32GB RAM @3.2GHz, Windows 10 1803

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raevol
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Re: Objects vibrating, issue 2737?

Post by raevol » 12 Feb 2016, 09:08

aesylwinn wrote:What framerate are you getting? (F3 in game should display fps)
In terms of magnitude, is the vibration slight or obnoxious?
Does it matter if you are very close (almost touching) to the object when it vibrates, at arms length, or farther?
Are you seeing the vibration only when making a turn, or can you also see it while moving in a straight direction?
50-70 frames
The vibration would be easy to miss if you weren't looking for it, but you would absolutely notice it eventually. And once you see it it's impossible to miss. It's the kind of thing that if you didn't know better you might assume it's supposed to be that way, but if you do know better it's impossible to mistake for an intended effect.
Distance doesn't matter but of course more distant objects are harder to see.
Easiest to see when strafing around objects, but it can still be seen with any player movement.

aesylwinn
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Re: Objects vibrating, issue 2737?

Post by aesylwinn » 12 Feb 2016, 16:48

Thanks. That information is very helpful. :D


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