post process volumes

[nicoladanese]

Hey

I'm looking into some volume post processing, I need to be very art directable on a volume after the sim so basically what I need to do is define areas where I need to increase density for instance, or decrease it. which is the best way?

[Andrea]

What do you mean by areas? If this are static areas/spots in the volume using a volume VOP is enough. If it's something that needs to be advected with the smoke simulation you need to also use the rest fields 

[nicoladanese]

hey! I meant a static area! how can I tell inside the volume vop to reduce the density inside a bounding box with some sort of smoothness? 

[evanrudefx]

I have had to do this before. I used a mixture of vops with ramps to fade density and vdb combine. 

[berglte]

Here's a simple VOP setup which uses a SDF to mask a volume.

volume_mask.hiplc

[nicoladanese]

thanks! really helpful!