Asger Mortensen

Hi, I have a question regarding the new Wind method in the Pyro Solver in Houdini 19.

From what I can tell, it's handled through a new parameter in the "gas advect field" nodes inside the solver. This new parameter is not present in the documentation.

- My problem comes with the lack of masking options for this wind. Say I'm simulating a chimney. I want to make the wind inactive inside of this chimney where the smoke is rising, and only be active when the smoke comes "outside" so to speak. It's an issue that I've faced on multiple projects, and I've solved it with hacking the Wind Force node before. The Wind Force node has some issues regarding scaling with substeps and it's difficult do get a natural "wind look" with it imo.

So my question is: Can you apply masking for the new wind parameter? If one were to implement this, how would one go about it?

I hope to hear from somebody. The last post I made regarding a similar question about the Wind Tunnel parameter didn't yield any response from you. And that makes me sad

Best Regards, Asger Mortensen

I have this exact issue. Is this something that the SideFX guys sees or?

Hi, I love the new "wind tunnel direction" feature in the sparse solver, and I would like to find a way to mask it's effect.
I know this is just a vector field node with "External Direction" set to a given value, but I don't know how to apply a mask to it (say I'm simulating a chimney with smoke rising out from the top. I wouldn't want the wind inside my chimney).

I can do this inside the gas wind node or with any other force node. The problem is: none of them look nearly as good as the "External Direction" option in the vector field node! (with gas wind being the worst).

I've tried using the "Sop Vector Field" node, and plugging in a sop field with the same value to what an "External Direction" value might be. It kinda works, but not quite. The result is not the same, and I noticed that the velocity field is getting incorrectly updated. (it flashes in and out of active areas when "activated") - also it's slower

I hope there is a Gas DOP expert who can help me. Basically what I want, is a wind that looks as natural as the "Wind Tunnel / External Direction" but with the ability for applying masking (and other stuff if possible).

Thank you so much, if you actually read this. Thank you even more, if you can help

Best Regards, Asger Mortensen.