I got two questions about performance in VR. I am using Unreal Engine 4.11.2.
- For testing I launched the game using the “launch” button to not have any editor overhead. First I use “r.setRes 1920x1080w” to see how performance is in regular mode, then I use “r.setRes 1920x1080f” to switch into VR mode. The editor is minimized all the time. I am not changing my view, the headset is not moved. I am reading the stats from “stat rhi”.
In regular mode, it’s 18,000 triangles and 66 draw calls.
In VR, it’s 170,000 triangles and 340 draw calls.
Why is there such a huge difference? Either the culling is less aggressive so that new meshes appearing if you quickly turn your head is avoided, or it’s all just due to the higher FOV in VR and the fact that everything is rendered twice?
- The game seems to be capped at 45 fps once the fps are anything below 90 fps. Can that be avoided or is it forced by how the Vive works? I would like to not go down to 45 fps if I could get solid 85 fps.