Frustrum Culling enhancement needed for VR

Right now I created a variant of our VR flight simulator with Unreal 4.26 and the CESIUM plugin. With some optimizations now runs between 75-90 fps using a VIVE Pro and a high-end workstation (i9-10900K CPU, RTX3090 GPU).

To run the sim using high-end headsets like the Varjo XR-1 / XR-3 or the new JVCKenwood HMD-VS1W with a stable framerate is still quite difficult even on high-end PCs like ours. So we need to optimize everything.

This leads to Frustrum Culling for the World Terrain: We have to switch it off, because the tiles are culled too soon, this shows at the edge of the field of view, 3DTile sections are visibly disappearing.

Could you improve this, by making the view frustrum that is used for culling bigger, or giving the user the option to do this? Or make the bounds scale for the actors that are culled bigger, so they are culled later?

Another big issue for the FPS are the exclusion zones, we need to exclude areas that are already detailed in sublevels (like airports) from the World Terrrain. But I think this is already in the works and we might hopefully soon get exclusion zones that are working across LODs.

Thanks for the awesome CESIUM plugin,


You’re right, the frustrum culling definitely needs work for VR. We are currently working on improving this, you can check out the pull request for updates on this feature, and test it out for yourself if you like.

Clipping planes/exclusion zones are also coming soon.

Very glad to hear you’re enjoying the plugin!

1 Like