[Sidefx-houdini-list] Killing cached sim particles

Chris Mangnall cm at dneg.com
Fri Oct 24 09:17:53 EDT 2008

The point sop has a shiny new 'match by attribute' toggle at the top.  
I'm sure you could use that, and the sop solver somehow...

Nicholas Pliatsikas wrote:
> Ah yeah that is a problem with the sop solver too, as all of this will be based on changing point orders. Darn it.
> I wonder if you can pass a custom attribute to the particles from the volume, and in sops pass the data to chops using $ID as your attribute to organise the chops with. Then somehow find the first peak in that chops attribute and set it to that for the rest of its life, dont forget to assign it back to the points using $ID again. Which would then allow you to delete the points. Im not sure how you find the max value and clamp it to that afterwards though. Just an idea.
> Hope you figure this out :¬)
> Nick
>> Date: Fri, 24 Oct 2008 14:39:42 +0200> From: ben.schrijvers at guerrilla-games.com> To: sidefx-houdini-list at sidefx.com> Subject: Re: [Sidefx-houdini-list] Killing cached sim particles> > Hi Andy,> > That's a tricky thing. The easiest is to do it at simulation time as you > might expect.> > In a cached situation you're best of in SOP's.> The tricky bit is that the Delete or Blast Sop only know about point > numbers but the point numbers of your particle system are probably changing.> What's not changing is the particle ID attribute. So you could use an > expression in the Delete Sop to delete the points in question.> Something like:> $ID==19338 || $ID==2403 || $ID==1653 || $ID==8328 || $ID==3278> > If it's a lot of particles that need to be deleted you might have to run > through the whole sequence and find all to be deleted points.> Somehow you have to get those ID's into a text file. Then make some > scripts that removes the doubles occurances and builds you the string > you need for the Delete Sop.> I've actually see people doing that in the past.> > succes,> benS> > Andy Nicholas wrote:> > Hi,> > Forgive the torrent of questions from me at the moment. I've got a tough> > simulation job on at the moment and it's turning out to be a great> > learning experience :-)> >> > Anyway, my question... I've cached some particles into some .sim files and> > I've then loaded them back in to an empty DOP network using a File DOP.> > What I'd like to do is to delete particles that venture outside a> > specified volume, but delete them permanently so that when their original> > trajectory comes back into the volume they don't reappear.> >> > I've tried feeding the File DOP into a popsolver and then putting it> > through a Kill POP in there, but no joy. I'm guessing there's a trick to> > this, but I don't know where to start looking.> >> > Any pointers on this would be gratefully received.> >> > Thanks> >> > Andy> >> > _______________________________________________> > Sidefx-houdini-list mailing list> > Sidefx-houdini-list at sidefx.com> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list> >> > > > _______________________________________________> 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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