Questions about RVT and SVT built from RVT volume

Thanks for your answer and new approach, they are helpful, we are discussing about the approach you suggested.

Can I ask a bit more about detail?

Regarding answer 3, if sampling different mips at the same location results in both mips stored in physical pool, it indicates more memory consumption. If the landscape and the grass at the same location use the same mip by default, adding mip bias to the RVT sampler in grass material requires more mips, which should increase memory usage. However, I saw in our project, after I added mip bias to the RVT Sampler in grass material, the memory usage went down (I observed it in r.VT.Residency.Show). Do you have hypothesis what happened here?

Regarding answer 5, are there anyway to generate high level mips by downsampling instead of always render/load the exact required mip level? There is another issue in our game when driving fast, the speed of RVT update is not fast enough. Sometimes I can see we are always running on blurry road, and after stopping, the landscape around the car was updated gradually. We tried to increase r.VT.MaxUploadsPerFrame and r.VT.MaxTilesProducedPerFrame, this helps a bit, but we cannot abuse them as too high r.VT.MaxUploadsPerFrame introduces too much cost to performance. Do you have good solution for this type of issue?