vdb vs aur

[TomGore]

Hello - could you please write down main differences when writing to specified file types?
I discovered that vdb doesn't carry particles (obvious) and is uncompressed (4x larger than aur compressed with rate of 15). But also, there are some resimulation issues reported on forum. Could you please specify any known issues with vdbs and resim/wavelet/retime?

best,
nl

[kostadin.petkov]

Hello,

AUR files use lossy compression (when the "Compression Quality" is below 20, at 20 there is no compression currently), that's why VDB files are much bigger. As for the known issues:

- Importing extremely large VDB files (2 billion voxels or more) isn't fully supported, so while importing Phoenix FD will downsample such files to grid size below 2 billion voxels. We are currently working on this.In addition fixing it should greatly decrease the import times.
- There is a small mismatch when resimulating between AUR and VDB files. We will fix this as soon as we can.
- We still export VDB v3 files, this is perfectly fine for now, but upgrading is in our TODO list.

Usually VDB files are used if you need Phoenix FD simulations in some other software that doesn't support AUR files.