What should I look at to reduce frame impact of TrueSky in VR? I noticed that reducing cloudiness even to zero had no effect, so it seems to be something unrelated to how the rendering actually looks. Same with decreasing resolution, removing depth blending, etc. Only when toggling Truesky visibility off completely does the FPS change, so I’m wondering what exactly is taking up the overhead if not the rendering.
The more I dig into this, it seems like most the cost comes from objects the intersect with the clouds, especially landscapes. I had a test where there was literally just True Sky and a large simple-mesh landscape with mountains intersecting the clouds. Both do fine on their own, but if both are enabled at the same time, frame rate drops like a rock.
But actually straight up disabling depth blending doesn’t actually help, so that stumps me there.
Could I ask which version of trueSKy you are using and whether you are using Unity, Unreal Engine or your own game engine?
The first thing that I would check is you are using multi-pass or single-pass instanced rendering.
Unreal Engine with TrueSky 4.1a
I have instanced stereo enabled.