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natstj 11-27-2018 04:43 AM

Oculus Stuttering after minutes of use
I'm having an issue where the display in my oculus stutters very badly after anywhere from a few minutes to an hour of usage. I only see this affect in the oculus and not on the monitor.

My update time, cull time, and draw time are all under the frame rate. The GPU time is also under the frame rate. However, my update time increases gradually over time (still under the frame rate when all three are combined though). Does anyone have ideas why this is happening or what may cause the update time to gradually increase?

Is this likely a code execution issue or a hardware issue? I'm using this for academic purposes so I'm really depending on high performance.

Thank you!

natstj 11-27-2018 06:01 AM

** Slight edit, I think it actually does show up on the monitor, but to a much lesser extent.

Jeff 11-28-2018 08:11 PM

A few questions:

1. What is the sum of update, cull, and draw times?
2. What does the update time increase to?
3. If you just load the scene models without any other code is there stutter?
4. What kind of graphics card do you have?

natstj 11-29-2018 03:41 AM

1. When it starts to stutter the sum is around 4 ms with the update time being about 2.5 ms. The oculus has a frame rate of 90, so I figured as long as the sum of cull, draw, and update times were under 12 ms it would be ok. The GPU is under 1 ms.

2. When it starts to stutter it increases to about 2.5, but if I leave it running despite the stutter, I've seen it go up to around 6. This is after maybe 60 minutes.
Another thing that confused me was that for the first minute or so, the frame rate reading is really high, (as in over 300) though it does settle to 90.

3. When I just load scene models, I don't notice any stutter. Though I was surprised to see that the update time was about 0.4 ms. It seemed high since I was not running any code.

4. NVIDIA geForce GTX 1080

Thank you so much!

natstj 11-30-2018 08:11 AM

Thanks for your help, the problem was a misunderstanding of the remove() function.

I was calling myNode.remove() without realizing it only removed the item from the vizard engine, and didn't remove the python object. This was causing the update time to increase each trial.

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