Compress vdbs

[MAYA_]

Heya!

I am looking into compressing down the size of my volumes and I have stumbled across compressing my vdbs down to 16 bit float. This make my guys nice and smaller and I don't see any difference in rendering but I am not 100% understanding whats happening behind the scenes here. Is there any disadvantages to doing this, such as loosing res?

I would be happy if someone could help me out with this!

Thanks

[celd]

Think of it as comparing an 8bit jpg and 32bit exr formats, they capture different ranges of data but can display the same thing. 16 bit volume will have a smaller range but still look correct enough under the right conditions.

So its the bit depth of the value of individual voxels.

Edited May 7, 2019 by celd

[MAYA_]

6 minutes ago, celd said:

Think of it as comparing an 8bit jpg and 32bit exr formats, they capture different ranges of data but can display the same thing. 16 bit volume will have a smaller range but still look correct enough under the right conditions.

So its the bit depth of the value of individual voxels.

Hey celd, 

thanks so much! This is a lot clearer now  I am wondering if this is something studios do in production or if this is a case by case kind of scenario? Just trying to figure out if this is something that I should be implementing into my future workflow, as there is defo upsides to having to store less data. 

[celd]

I would say it depends on the studio, usually the larger studios should have plenty of space to spare. If you are however really starved for space I dont see why you couldnt do it, just be careful when compressing vector fields like this, I found it can remove too much information sometimes.

[MAYA_]

25 minutes ago, celd said:

I would say it depends on the studio, usually the larger studios should have plenty of space to spare. If you are however really starved for space I dont see why you couldnt do it, just be careful when compressing vector fields like this, I found it can remove too much information sometimes.

I see, thank you! Do you recon it would make sense to pull out the fields that might be less important and compress these separately, but leave important stuff as it is? I am mostly trying to save space and making this whole process more efficient with a limited amount of storage for huge scale sims  If you have any other suggestions in that area, I would be excited to hear!

Edited May 7, 2019 by MAYA_

[pclaes]

Before going into rendering we tend to compress all volumes to 16 bit. There is no noticeable difference for rendering and almost a 50% space savings.
Only thing to really be careful with vdb is pruning with rest volumes (they really should not be pruned as 'zero' is a valid rest value.)

During the simulation you want the full 32-bit as that accuracy is needed for the fluid solve, but once you are done with the sim (and any post processing) you can go down to 16-bit.

[kleer001]

4 hours ago, celd said:

I would say it depends on the studio, usually the larger studios should have plenty of space to spare. If you are however really starved for space I dont see why you couldnt do it, just be careful when compressing vector fields like this, I found it can remove too much information sometimes.

Sometimes I half the resolution of my velocity fields (double the grid size). But not with density or anything else.

[MAYA_]

13 hours ago, pclaes said:

Before going into rendering we tend to compress all volumes to 16 bit. There is no noticeable difference for rendering and almost a 50% space savings.
Only thing to really be careful with vdb is pruning with rest volumes (they really should not be pruned as 'zero' is a valid rest value.)

During the simulation you want the full 32-bit as that accuracy is needed for the fluid solve, but once you are done with the sim (and any post processing) you can go down to 16-bit.

Hey pclaes! Thanks this is super helpful! I was thinking the same thing but I did not want to start doing this and then get problems when rendering later on that I might not like initially notice. Also yeah this was only thought to be a post simulation, pre rendering thing  

Edited May 8, 2019 by MAYA_