Help strange slow down on tests

[usemahrope88]

hi!

http://obi.virtualmethodstudio.com/performance.html


the docs say you have 1-9 characters running at decent FPS,

ive been struggling figuring it out, but on say charactercloth example im getting horrible FPS drop when 3 duplicates are made of original character, 1-2 runs ok, but third one ALWAYS tanks FPS... i dont understand it

still a great asset, it seems ill maybe have to accept simulate only 1-2 objects at a time for now

any tips for what to enable and disable to make top performance?

thanks dev!

[josemendez]

Hi!

Make sure you're using the Burst backend, as that will yield better performance (see the setup guide):
http://obi.virtualmethodstudio.com/manua...setup.html
http://obi.virtualmethodstudio.com/manua...kends.html

1-2 runs ok, but third one ALWAYS tanks FPS... i dont understand it

This is because of Unity's fixed time stepping scheme. The third character is causing Unity to perform additional physics updates every frame, which will tank performance. This means the overall per-character cost is high, either because of the backend used, settings used, or your hardware.

You can tweak your timestep parameters to avoid this. Specifically, increase your fixed timestep or reduce your max fixed timestep (usually, a small multiple of the fixed timestep value is a good choice). See:
https://docs.unity3d.com/Manual/class-TimeManager.html

If you're unsure what fixed time stepping is and why it can make or break performance (understanding it is crucial for any physics work in Unity), there's many resources out there. This one is probably the best one:
https://johnaustin.io/articles/2019/fix-...y-timestep

any tips for what to enable and disable to make top performance?

- Use as few substeps as you can get away with.
- Use as few constraint iterations as you can get away with.
- Disable constraints you're not using.

The manual explains how the engine works internally and what substeps/iterations are and how they affect performance vs quality: http://obi.virtualmethodstudio.com/manua...gence.html