Lukich Posted November 1, 2004 Share Posted November 1, 2004 Hello there. I was playing around with emmiting the particles using the COPs reference to transfer the colors to them. Then I tried to put all the particles with $CB==0 into a group and kill it. It works, but only partially. I guess, only about 4/5 of the particles gets killed right away, but I still have a number of particles poping up in random places only to disappear at the next frame. I'm pretty sure that they belong to the group of $CB==0, because the background of the image is pefectly black. Do you guys know how to overcome that? It's very disconcerting Thanks a bunch! Here's how it looks like: Quote Link to comment Share on other sites More sharing options...
Lukich Posted November 2, 2004 Author Share Posted November 2, 2004 Figured it out, works great with the Delete SOP. Is the Kill Pop not very reliable or is it just me? Quote Link to comment Share on other sites More sharing options...
stevenong Posted November 2, 2004 Share Posted November 2, 2004 It depends on how your popnet is set up. Without seeing the network, I can't tell you why it doesn't work the way you want it to. Also, POPs is iterative which means particles' attributes & values are added from frame to frame so if you want something to happen on frame 100, you have to make sure the expression is executed on frame 99. If I didn't explain the above clearly, I'll try again. Cheers! steven Quote Link to comment Share on other sites More sharing options...
Lukich Posted November 2, 2004 Author Share Posted November 2, 2004 here's the popnet. it's quite basic, really. cop.zip Quote Link to comment Share on other sites More sharing options...
stevenong Posted November 2, 2004 Share Posted November 2, 2004 Hey Luka, It's the iterative nature of POPs that's causing the delay. Ondrej also mentioned it in his post over at the SESI forum. As you've already found out, you can kill the particles at the SOP level. Alternatively, you can birth particles where there's colour or not. You can do this in the Source POP with the following expressions in the "Birth Probability" fields: pic("../cop2net1/default_pic",$BBX,$BBY,D_CR)>0 || pic("../cop2net1/default_pic",$BBX,$BBY,D_CG)>0 || pic("../cop2net1/default_pic",$BBX,$BBY,D_CB)>0 If you only want to have particles where there's red or green, remove this "pic("../cop2net1/default_pic",$BBX,$BBY,D_CB)>0" from the expression. Enjoy! Cheers! steven Quote Link to comment Share on other sites More sharing options...
Lukich Posted November 2, 2004 Author Share Posted November 2, 2004 Groovy! Thanks a lot, Steven! I'll give it a try. Quote Link to comment Share on other sites More sharing options...
deecue Posted November 3, 2004 Share Posted November 3, 2004 also, it's good to write out your particles if you are at a point where your network is "done".. just throw your bgeo sequence somewhere and bring it back in through a file sop and delete the appropriate points then through whatever variable\attribute.. the advantage of this is a number of things: speed, accuracy (predictability wise), and the ability to scrub back and forth.. hth, dave Quote Link to comment Share on other sites More sharing options...
edward Posted November 4, 2004 Share Posted November 4, 2004 You could also just increase the popnet's cache size. Of course, then you need to wait for it recook every time your re-open your hip file. Quote Link to comment Share on other sites More sharing options...
Lukich Posted November 4, 2004 Author Share Posted November 4, 2004 The more I work with houdini the more it amazes me how many different approaches one can take Thanks a lot, guys! Quote Link to comment Share on other sites More sharing options...
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