[Sidefx-houdini-list] Killing cached sim particles

Chris Mangnall cm at dneg.com
Fri Oct 24 09:45:08 EDT 2008


I've mailed you a solution using the sopsolver... it's not very quick 
though :(

Andy Nicholas wrote:
> Thanks a lot Nick. Yep, I figured that I could probably use CHOPs somehow.
> Thanks for digging that solution up.
>
> (I'm disappointed by DOPs though, I'd have thought that this sort of thing
> should be bread and butter for it. )
>
>
>
>   
>> Ok this would work.
>> Just use the count chop to set the custom delete attribute to clamp from
>> its highest value for the rest of its life :¬) Might be worth setting up a
>> nice little digital asset for this, as its useful for more then just
>> particles but other time/volume based geometry deletion.
>>
>> Might get alittle sluggish and heavy in memory usage as it is Chops after
>> all.
>> Nick
>>
>>
>>
>>     
>>> From: nick_p102 at hotmail.com> To: sidefx-houdini-list at sidefx.com> Date:
>>> Fri, 24 Oct 2008 12:58:39 +0000> Subject: Re: [Sidefx-houdini-list]
>>> Killing cached sim particles> > 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>
>>> _________________________________________________________________> X
>>> Factor: latest video, features and more. Click here!>
>>> http://clk.atdmt.com/GBL/go/115454063/direct/01/>
>>> _______________________________________________> Sidefx-houdini-list
>>> mailing list> Sidefx-houdini-list at sidefx.com>
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>       
>> _________________________________________________________________
>> Catch up on all the latest celebrity gossip
>> http://clk.atdmt.com/GBL/go/115454061/direct/01/
>> _______________________________________________
>> 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
>   



More information about the Sidefx-houdini-list mailing list