Max Axis or Division Size?

[magneto]

In standard volumes Max Axis is the default for setting volume resolutions, while VDBs use Division Size by default. I know standard volumes also have a Division Size option, but VDBs seem to mostly provide Division Size as the only option from what I have seen.

Which method do you use when working with volumes?

Reason I am asking is to me Division Size (Voxel Size, By Size) seem like a more logical unit. If I use Max Axis, and scale the volume, the detail will decrease, right? So I always have to compensate to retain the same level of detail. Division Size will always retain a fixed detail regardless of the size of the volume?

There is no way to know what a particular value for Max Axis might look like for a given volume without knowing its dimensions. For example when inspecting someone else's file. But a voxel size of 0.1 will always look the same regardless of the volume size. More of a fixed unit of resolution.

Lastly if you are using Max Axis, how can you make sure the voxel size is the same across multiple volumes of different dimensions? You would have to figure out the math yourself.

If standard Houdini volumes and VDBs use different defaults for this, I think it's worth discussing

[anim]

It can't be said one is better than the other in general, both have their uses

Division Size - keeps the same voxel size regardless of the dimension of the source object

Max Axis - keeps the same voxel density relative to object's bounding box

I personally found myself using Division Size much more frequently, but for example in RBD volume representation I prefer using the default Max Axis as it's usually what I want for that case

I don't feel any need to force the same defaults for VDB and Houdini volumes as you usually need to adjust the value anyway so choosing the mode is not a big deal

[magneto]

Thanks anim. What is the reason of using division size for RBD volumes? Is retaining volume density in that case more important?

[anim]

as I said, for RBD volumes I use Max Axis and the reason is that rbd objects have usually lower detail, so I care more about certain number of divisions per object and not about the size of the rbd, because the fact that the RBD is bigger doesn't mean that I want it to be subdivided more than similarly shaped but much smaller one

but sometimes you may want to prepare collision volumes in exact voxel size especially for detailed collisions for fluid sims , in that case you may prefer to use Division Size

[magneto]

Thanks anim, I got it now