[SOLVED] Stuttering while maintaining stable framerate

[Rob]

In our world we experience somekind of micro stutter while we move around, as we look at our framerate and the profiler we see that everything seems to be stable

So what could be causing this? When we enable Vsync the stutters seem to get a lot less but still we see stutters every now and then

[ulf.schroeter]

Are you using SLI dual GPU's ?

[Rob]

Nope just a single GTX 670

[frustum]

This bug has been fixed already. Wait for the next SDK.

[Rob]

Ok great news!

[nitrooo]

I think the problem is not solved. I just tested "Third person platformer" demo and I faced such stuttering. To confirm the problem, I created and compiled "Programming Quick References" example in c++ and the same stuttering occured. I played around with all physics setting and nothing helped. Next I run my Unity project and there was not stuttering at all. So the problem is with Unigine.

Any suggestions to solve this problem?

By the way - there is a bug with physics settings in editor (world->physics->fps). I can change fps from 60 to 30 or 10, but I can't revert it.

[silent]

Quote

By the way - there is a bug with physics settings in editor (world->physics->fps). I can change fps from 60 to 30 or 10, but I can't revert it.

Yes, we saw similar reports in discord, but so far wasn't able to reproduce them. Are you running Windows or Linux?

 

Quote

I think the problem is not solved. I just tested "Third person platformer" demo and I faced such stuttering. I created and compiled "Programming Quick References" example in c++ and the same stuttering occured. 

Could you please record a small video where we can see these stutters? Also if you can send us engine log file from any of this demos after running it would be great (usually it's located in bin directory and named as log_*.txt).

Thanks!

[nitrooo]

I am running Windows. I have uploaded the files to your ftp:
1. physics fps bug.mp4
2. stuttering.mp4
3. no stuttering unity.mp4
4. stutter_log.txt
While recording fps dropped by half, so stuttering became even worse, but in Unity animation stayed smooth. If you need my test project zipped, just let me know.

[silent]

nitrooo

Thanks for the files, indeed there is something wrong going on here.

The project itself would be good to check as well. Maybe there is some issues with scene/physics configuration, need to double check.

[nitrooo]

I uploaded my test project  cpp_test.zip. I am very curious about this problem. First I thought, that maybe it was garbage collector problem in "third person platformer" but after testing c++ example project, I am kinda confused. Maybe I am doing something wrong...

[silent]

Just tried with your project and looks like everything runs smooth (tested with Win 10 21H1 and RTX3060).

If you really want to limit your app to the monitor refresh rate it's better to use a regular vsync and enable fullscreen mode. In that case there will no side-effects from render_max_fps.

Also I can somehow get similar behavior to your stuttering when another 3D application is running in background (even Chrom with hw-accelerated GPU decode can cause such behavior).

Thanks!

[nitrooo]

I tested everything in fullscreen mode, after PC restart and without any other apps running. I played around with fps, vsync, physics fps and other settings, also with NVidia settings. Nothing helped. All the demos including "Superposition" and "Third person platformer" stutter. Next I run Unity, Unreal or any game and there is no stuttering at all. There must be something wrong with Unigine.

[werner.poetzelberger]

Hi. Not sure what your issue is, but we also had some issues with max fps.
So this you can use in some cases, but better to use other method for limiting framerate.

Best.
W.

[nitrooo]

I don't have a problem with frame rate but with stuttering. It looks more like a problem with vsync or multi threading. But other engines and games run smoothly so there is something wrong with Unigine.

[werner.poetzelberger]

Interesting to know what that is for sure.
Actually we had sometime also some micro activity which we couldnt find out what it was. 
But this was definitely project dependent.
In general we cant say that the Engine itself has an issue, or certain Engine versions.
We are running many different Engine versions on many different systems and we never got into a position where we would say, the Engine has a continuous issue.
Would be interesting what that is in your special case.

[nitrooo]

After more tests, I know the problem is Vulkan. When I select Vulkan in global options and I have VSync enabled in NVidia settings, there is stuttering in all the demos. When I select DX11 or DX12, animation is smooth. Best, stutterless results I got with DX11 or DX12 with Adaptive VSync enebaled in NVidia settings.
 

[silent]

Yes, Vulkan API is still in experimental stage. We will see what can probably cause this behavior and fix this bug in the future versions.

Thanks for the update!