Hello guys! I would like to ask you what do you think it would be the best approach to absorb a volume in a DOP simulation in Houdini. I thought of one but it might be wrong:

Creating a spherical volume, then with Volume VOPS storing the gradient into an attribute and using it as a scaled force inside the DOP network. What do you think?

Is there any other approach it comes to your mind? Thanks!

Absorb a volume?

Probably a combination of things:
- pump to suck it around
- expand set up in reverse to allow the gases to compress as they get sucked toward a point. Don't forget this as you can only compress smoke so far without divergence in reverse.
- sink to evaporate the smoke

How you construct those various volumes, hey, it's up to you. Gradient. Sure. You can just create a velocity field and then volume blur to soften the edges too. Many ways to construct these volumes. You can get pretty far with the Fluid Source SOP

See the attached file for a sketch setup. Hope this is what you were asking for (a bit terse on the details…)

jeff
Absorb a volume?

Probably a combination of things:
- pump to suck it around
- expand set up in reverse to allow the gases to compress as they get sucked toward a point. Don't forget this as you can only compress smoke so far without divergence in reverse.
- sink to evaporate the smoke

How you construct those various volumes, hey, it's up to you. Gradient. Sure. You can just create a velocity field and then volume blur to soften the edges too. Many ways to construct these volumes. You can get pretty far with the Fluid Source SOP

See the attached file for a sketch setup. Hope this is what you were asking for (a bit terse on the details…)

Hey Jeff! Mate thanks a lot! This is being so helpful to me! But first I should take a closer look to the Pyro simulations. I know what divergence is, but I don't have the hang of the different types of volumes in the Pyro simulation, I will try to watch some tutorials about them before I start adapting your workflow onto my scene.

I really appreciate taking your time guiding me! I will ask you some more questions after I learn it! Cheers.

Ask away if you have any questions. It is important to know what each of the various fields in DOPs are used for and then you can start to use them to do what you want.

jeff
Ask away if you have any questions. It is important to know what each of the various fields in DOPs are used for and then you can start to use them to do what you want.

This is perfect, thanks a lot. I was thinking though to add some noise to break the linerar shapes when it gets sucked, should I use a Noise Field and advection or should I just add a Wind node afterwards with some noise on it? Sorry for so many questions but I also would like to know whether it would be possible to display the volume as smoke, and not as this sort of polygon soup of white thingies, when I press render it displays the volume correctly but I seem to be having issues with the viewport maybe. I tried at Linux and Windows machines and they all display it like that. Any idea?

Thanks a lot for your patience.
All the best.