Mcronin Posted February 19, 2003 Share Posted February 19, 2003 OK, I've been trying unsuccessfully to scale particles individually based on age. I tried using an age attribute, and a couple other thinngs with no success. I'm no real clear on how to use the age attribute and $LIFE doesn't seem to work as I expect either. Basicly I have a Source POP with a Render POP appended to it. I've been trying to use the particle scale paramter in the Render POP with a wave CHOP to scale the particles individually based on their lifespan. All the expressions I try give me errors, and the only thing I have been able to do successfully, is scale all the prticles in unison based on time. Can anyone help? Quote Link to comment Share on other sites More sharing options...
miguel m Posted February 19, 2003 Share Posted February 19, 2003 removed it: i thought you were going back to sops from pops. Quote Link to comment Share on other sites More sharing options...
edward Posted February 19, 2003 Share Posted February 19, 2003 Try changing the PSCALE attribute in the Property POP instead of the Render POP. Turn on Scale and replace $PSCALE with $AGE. That should give you some changes. Quote Link to comment Share on other sites More sharing options...
Mcronin Posted February 19, 2003 Author Share Posted February 19, 2003 Thanks Edward! I'm new to particles and wasn't aware of the Property POP. You've opened a door to a whole new world to me, seriously. Quote Link to comment Share on other sites More sharing options...
Mcronin Posted February 19, 2003 Author Share Posted February 19, 2003 Got it all sorted now, well at least I'm getting the results I want. This is the solution I came up with. I'd like to run it by you guys and if there's a better way to do this please enlighten me. I wanted to scale particles individually over their life. What I wanted to do is grow the particles from a scale of 0 at birth, to a specific maximum size, and shrink them back to 0 as they die. I have my Source POP with a Property POP appended to it and the Scale property enabled. I add a spare channel to my Source POP named "SparePScale". In this spare channel I created a curve, 10 frames long with three keys. 0 to start, my max value around frame 7.5, and 0 again at frame 10. I applied ease functions on each segment to get a smooth transition, In the Property POP I put this in the Scale field: chf("../source1/SparePScale", $LIFE*10) Now like I said this works for me, but I'm really new to this stuff, and was wondering if there's a better or more proper solution for this. Quote Link to comment Share on other sites More sharing options...
edward Posted February 19, 2003 Share Posted February 19, 2003 I'm no houdini wizard but i can't see anything wrong with that .... Someone who actually does effects might want to comment Cheers! Quote Link to comment Share on other sites More sharing options...
jimmyb Posted February 20, 2003 Share Posted February 20, 2003 cool idea, How did you add a spare channel and and a curve to it? Do you have a hip file? thanks Quote Link to comment Share on other sites More sharing options...
jimmyb Posted February 20, 2003 Share Posted February 20, 2003 never mind.....figured it out! thanks Quote Link to comment Share on other sites More sharing options...
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