For those wondering what Multiview instancing does. It basically saves on some rendering costs by rendering the scene once for the left eye, and then shifting and adjusting the image for the right eye. This works as intended on smaller FOV headsets like the Index. But for wide FOV headsets, the rendering gets messed up. So disabling it, means rendering the same image again for the right eye.
I think the best way to test this is to disable half life alyx’s auto fidelity system and set the fidelity to the very max like this:
+vr_fidelity_level_auto 0 +vr_fidelity_level 8
And then go into a wide open space in HL: Alyx and compare the performance difference between my method with and without volume fog enabled versus just using parallel projection. I suspect my method will yield a much higher performance because PP renders an entire scene twice (once per eye) which is very costly. Someone with an 8K-X should test this.
I get a smooth performance and a decent image on my StarVR One by leaving auto fidelity on, disabling volume fog, running at the lowest refresh rate 72Hz (90Hz is fine but lower results in better image), disabling motion smoothing, and under alyx graphics setting Characters -> Low , Shadows -> Medium, Fog -> Medium. (Character setting has nothing to do with character detail apparently)
Update: Turns out that disabling multiview rendering has almost no affect on GPU but mostly on the CPU.
Single Pass Stereo rendering (also known as Multiview rendering on OpenGL/Vulkan) is a rendering feature for Oculus devices running on Android. It is available with the Unity version 5.6.
In a typical OpenGL stereo rendering, each eye buffer must be rendered in sequence, doubling application and driver overhead. With Single Pass Stereo rendering, objects are rendered once to the left eye buffer, then duplicated to the right buffer automatically with appropriate modifications for vertex position and view-dependent variables such as reflection. It primarily reduces CPU usage, and the GPU performance is unchanged largely. If your application is CPU-bound or draw call bound, we strongly recommend using Single Pass Stereo rendering to improve performance.
Today, I received my second StarVR One unit, however it is the ‘XT’ version. That one uses a different tracking system so, It may use a different software to run it.
Interesting finding between the two units:
The Lenses. They are different. The none xt have the typical Fresnel rings texture. But the XT does not, is a complete smooth lens. Unfortunately, since it does not run with Compass i cant test the visuals
Hey @NextGenVR - I tried it with the 8k+, works just fine and finally all those fluids look hmm “nice” ;-).
Cool thing! I think I will be playing Alyx more then once - just an awesome VR Experience that keeps getting better!
I did not try a performance delta - without you parameter and with PP and with your parameter and without PP . If I get the time I will try.
I know how the trick works, thanks for explaining. But if you use fpsvr do you realy see performance gains? Maby in game the pop up and culling ting is doing weird things wen you don’t see them with the trick on. And remember when you don’t use pp pistool render the game in les resolution so whe have to test the difference with the same resolution. @NextGenVR@SweViver
Curious about your settings in Half Life, I’m getting aliasing on certain objects. Extremely noticeable on the giant power lines linked to the tower during the intro part on the balcony. Is there a setting to adjust for this or do you see it at well?