Evan Robinson


About Me

VFX Artist

Maya vfx artist/student switching to houdini.


Recent Forum Posts

Swirling Motion Pyro July 23, 2018, 10:53 a.m.


I am having a difficult time figuring out the best way to get swirling motion in a pyro sim. In Maya, we have the swirl attribute.
You can see the swirling motion in this sim that I did here: https://vimeo.com/141476011 [vimeo.com]

Disturbance doesn't seem to add swirl, but random detail to make the sim look more interesting. You can easily break the sim and get weird patterns if this is turned up too much.

Turbulence seems to add somewhat of a swirling motion, but in every direction rather than in the direction the smoke is headed. As the documentation says, its works best at large scale

I tried the seed vorticles shelf tool. It is slow and doesn't seem to work well with resizing containers. It's ok when used at low scale. It creates weird patterns when scaled too high.

I tried many micro solvers. Gas confinement seems good, but there isn't really a way to set the scale of the swirl. I tried remapping and that helped a little bit. Gas vortex equalizer also creating strange patterns. The only micro solvers that seemed to add swirl are gas vortex boost and confinement.

I also noticed that you can often tell if a simulation is done using pyro because of patterns that disturbance and turbulence create. Take a look at some of these pyro simulations. They all have the same pattern that disturbance creates. The other look you can get from pyro is from using a lot of confinement. It creates a lot of swirling motion, but very tiny swirls.

https://vimeo.com/album/5305665 [vimeo.com]

Any help would be greatly appreciated.

VDB sop July 20, 2018, 8:39 a.m.

thanks : )

VDB sop July 19, 2018, 2:20 p.m.

What is the purpose of the VDB sop? The only time I have seen it used is with volume rasterize particles when creating white water. What other times would you use it? Also, what is the point of the visualization? The documentation says the node is creating empty vdb's so what is there to visualize? Also, I can't get it to actually show anything other than the bounding box showing the voxel size.

thanks in advance.