advect smoke by particles

[Franz]

Hi,

I'm looking for a way to turn a particle animation into a smoke simulation which follows the movement of the particles but also creates some additional swirls and detail. I already tried to copy the particle velocity to the vel field via a gas particle to field dop but this doesn't seems to work in this case. The smoke kinda sticks to its position without following the particles in the correct way and it's also difficult to control the overall look of the simulation. Is there a better way to archive this effect ? I'm new to Dops and can't figure out what's going wrong here.

[Netvudu]

Just to refresh my head from painful Python scripting I decided to give a quick look at your problem.

Maybe my solution won´t look as glamorous or technical as you might be expecting, specially after I took a look at your scene and it´s a quite complex one indeed!

But, you know, sometimes less is more, and before I start playing with copying fields around I tend to play with what the current toolset can offer. After all I don´t want to build something that´s already there

Is this what you´re after? It´s a bit high on disturbance, but you get the idea...

ParticlesCreateSmoke.mov

If it is, as you´ll see from the hip file it´s nothing special. Just particles used as volume source (remember to use "Stamp Points" as your method, not "Build SDF from Volumes"), no bouyancy, lots of drags, little sourcing, turbulence and disturbance mostly.

Here´s the hip file. I appologize in advance if you expected a more technical solution, but this one works and is very easily tweaked.

ParticlesCreateSmoke.hipnc

Hope this helps.

[bhaveshpandey]

one of the easier ways is to source the velocity of the particles into the smoke sim along with

sourcing smoke from the particles..this will mix the particle velocities into the smoke sim.

edit: the gas particle to field dop works by splatting the particles into a field which is based on a

radius or distance from particles..so you will have gaps in you velocity field which is the reason that

your smoke sort of stops at some places..a work around would be to increase this as well as use a blur on top of it?

this will sort of expand and fill in the gaps (or regions with no vel data in the fields)

also instead of copying the vel to smoke, you should add it with the smoke's velocity,

this will ensure that the regions with no vel data will not get stuck.

Edited June 19, 2012 by bhaveshpandey

[Franz]

( double post )

Edited June 19, 2012 by Franz

[Franz]

Thanks for your quick feedback

I didn't had time to try your technique yet, Netvudu but your example file really looks promising - it's definitely going in the right direction of what I'm trying to achieve. I tend to get lost in details when it comes to working with Houdini - so I'm quiet happy that you came up with this simple solution

@ bhaveshpandey ; I already tried this procedure and found it a bit too difficult to control – but thanks for all that additional information about the gas particle to field dop -

changing the calculation type to add really made a big difference.

I'll do some test at the weekend when I got my head free of all the school projects which keep me from doing any Houdini stuff at the moment.

Many thanks for your help

[Franz]

alright - here's the result of one of my first tests - the new technique really works pretty good

http://dl.dropbox.com/u/67369362/flipbook_1.mp4

(looks like i don't have the permission to attach the file directly)

[eman305]

hello all

I was trying to do just what you were doing but I have know idea where to start. I was going to take a look at the hip file but its not there. I tried to make it work with the information I got from bhaveshpandey post but I couldn't.

can anyone help me out.