[Sidefx-houdini-list] Smorganic

Ozgur Yılmaz eoyilmaz at gmail.com
Tue Apr 20 01:37:13 EDT 2010


jiversen, because I'm so new to the DOPs thing I can't really measure the
value of that RFE for now, should be something awesome.

paul flanagan, thank you for your advice I will definitely look at that
example.

alright, let me sum up what I have done last night. I was not able to
calculate the divergence by using the Gas Analysis node, I think the tool is
for volume fluids. And I tried to use Gas Particle to Field node to get a
volume representation of my particles, with no success. So I left the DOP
context and done the rest in SOP.

Because the particle had all the information about the state of the fluid at
the particles position it was relatively easy to calculate the divergence of
every single particle. I've used point clouds to gather the information
about a particle and its environment which is needed to calculate the
divergence.

But there was a subtle error ( may be bigger than subtle ), there is a
smoothing kernel term which I need to use while calculating the divergence
to add the influence of a nearby particle. The problem is, I don't know how
to change the point clouds interpolation so it matches the smoothing kernel
of the fluid nor how to iterate over every single particle that the point
cloud gives me. And actually there is another problem, I don't know what
smoothing kernel Houdini has used. May be it is related with the simulation
method parameter which is currently set to Runge-Kutta 3(2).

Anyway, I calculated a divergence vector and used its length as the
divergence value at that position, then I grouped the particles with
relatively high divergences ( around 0.001-0.01 ) and used them as source
for new particles which led me to explosions again.

I need to progress by first approving that I have a correct divergence
value. Than I need to change the way I calculate the source positions for
new particles.

So I'll let you now if there is any good news.

Cheers

E.Ozgur Yilmaz
Lead Technical Director
www.ozgurfx.com


On Tue, Apr 20, 2010 at 1:31 AM, paul flanagan <paulflan at gmail.com> wrote:

> hey Ozgur,
>
> if your very new to Houdini particle fluids id recommend you load up
> the GrogSplash example file  have a look how its meshed etc.... its in
> the docs..  just a thought.
>
> p,
>
> On Fri, Apr 16, 2010 at 2:56 AM, Ozgur Yılmaz <eoyilmaz at gmail.com> wrote:
> > is there any idea how to do a similar effect with houdini particle
> fluids:
> >
> > http://www.fusioncis.com/pr_smorganic.html
> >
> > E.Ozgur Yilmaz
> > Lead Technical Director
> > www.ozgurfx.com
> > _______________________________________________
> > Sidefx-houdini-list mailing list
> > Sidefx-houdini-list at sidefx.com
> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
> >
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