I have 2 maps, 1 non VR, and 1 that is optimised for VR. By default it is in the non VR mode, when I switch to VR mode I open the VR map and I am getting bad performance. But if I start the application in the VR mode I am getting 90FPS.
I have tried using the Openmap blueprint node and the console command to try to switch between levels and I am still getting the performance drop.
I was unable to reproduce this issue on our end. I did not see a difference in performance while switching between levels (to a level with enable HMD). How much of a frame drop are you seeing when switching between levels? If you use identical levels does this issue still occur?
When the VR level is loaded first I get 90 fps, if not I am getting around 40-50 on a GTX 1080. I originally did have the same level for VR and non VR but because of the dynamic lighting (time of day feature) in our non vr map we optimised and used static lighting.
With the additional information provided I was able to find that this appears to be a known issue. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.
Reprojection kicking in when you don’t hit framerate (90) and pulling you back to 45 is intended. The issue that was resolved was the choppiness that was being seen once the drop occurs. You may drop to 45, but it’s still nice and smooth due to the interleaving of frames. I hope this information helps.