Unity tip: Enable IL2CPP for performance gains

[l0g1k]

I only recently realised I could use this feature, and turning it on reduced the CPU time for the OvrAvatar update loop from 1.5 ms to around 0.8 ms  - saving around 0.7 ms per avatar on an S6. If you don't know, it translates C# to native binaries. There is a lot of really slow MS native inter-op code in the Avatar SDK that seems to have benefited a lot from that.

Hopefully this helps someone else. Make sure you use a late-2017 or newer Unity as there were lots of bugs floating around before then I think.

PS: Another tip for lowering processing on lower end devices is that if the user does not have a controller connected, and is alone in the scene, you can disable OvrAvatar completely and save a bit of time, since the avatar is likely not doing anything in the scene at that point anyway (unless you have other cameras for some reason).

[Preston_Jong]

I will for sure try this.   I'm always looking for ways to optimize.   My game right now maintains 90 FPS, but the headroom is around 3% to 15% with an NVIDIA 1070.   And on my transition scenes I'll disable the OVRAvatar completely.   Thanks for the tips.

[l0g1k]

imperativity said:

Thanks for your feedback and contribution to this forum!

Thanks!

As follow-up there is some small change needed to the AvatarSDK usage to support this

Find the method "MicFilter" and add this attribute " [MonoPInvokeCallback(typeof(CAPI.FilterCallback))]". (Add "using AOT;" to the file)

Please note the MicFilter content might have changed by the time you read this so don't copy/paste; just find it and add the attribute like so

[MonoPInvokeCallback(typeof(CAPI.FilterCallback))]
public static void MicFilter(short[] pcmData, System.UIntPtr pcmDataLength, int frequency, int numChannels)
    {
        float voiceMax = 0.0f;
        float[] floats = new float[pcmData.Length];
        for (int n = 0; n < pcmData.Length; n++)
        {
            float cur = floats = (float)pcmData / (float)short.MaxValue;
            if (cur > voiceMax)
            {
                voiceMax = cur;
            }
        }
        voiceCurrent = voiceMax;
    }