Disturbing the surrounding velocity field outside of the density field

[Pierre-Simon_Henri]

Greetings.

Pleasure to meet you all. I've been a lurker since many months, but now it's time to get out of my cave and meet you all.

I read a thread recently while searching a way to disturb the surrounding velocity field outside of the density field:

http://www.sidefx.co...75a9372ca8f2f97

Jeff said it could be possible to inject some kind of curl noise everywhere excluding the density by using a gas field VOP?

To be honest, i've been using Pyro for a few weeks now and been using fumefx before so this is kind of overwhelming. I can't seem to make it work. I have never used a Gas field VOP before. I checked the documentation of the gasfieldvop, couldn't find an appropriate examples that use this node?

Could any of you lend me a hand and give me a simple scene where i could see the process?

My goal? I find that the velocity field in my pyro simulation , outside my density field, like Jeff said, a bit too round when it's first emitted. I would like to create some noise outside to break up the edge.

Thanks again.

Edited February 18, 2013 by Pierre-Simon_Henri

[Ankit Sinha]

You can use vel blur and subtract it from vel field, here is step to create it :

1 create vel blur field(with gas match field node)

2 copy value of vel field in vel blur( with gas calculate node)

3 the blur the velblur field (with gas blur node)

then in gasfieldvop

import both attribute(vel and vel blur), subtract them and the add the result to the vel field and output the result at as vel field again (this may not giv you result straight away you may have to do some mathematical operation to tweak result inside vop)

final step

merge the four nodes(gas match field , gas calculate, gas blur and gasfieldvop)

hope this will help.