MENOZ Posted December 22, 2011 Share Posted December 22, 2011 hello, If I emit particles, and add a kill pop with rule set to 1, or a AGE pop with lifespan set to zero, It seems that those nodes deletes the particles on the next frame. So I have a popping effect that is not what I want, and I need to delete those "one frame particles" back in sop. can anybody explain me how those things are working inside? Can be a possible RFE? thank you Quote Link to comment Share on other sites More sharing options...
3dbeing Posted December 22, 2011 Share Posted December 22, 2011 Can be a possible RFE? The kill pop set to 1 means kill all paricles, so the particle is born lives 1 frame then dies cuz a particle can't birth and die on the same frame. Life set to 0 is the same thing. No rfe here, this works as expected Quote Link to comment Share on other sites More sharing options...
Ronald Posted December 23, 2011 Share Posted December 23, 2011 hello, If I emit particles, and add a kill pop with rule set to 1, or a AGE pop with lifespan set to zero, It seems that those nodes deletes the particles on the next frame. So I have a popping effect that is not what I want, and I need to delete those "one frame particles" back in sop. can anybody explain me how those things are working inside? Can be a possible RFE? thank you Hi Menoz, I am not sure what you are trying to do, you set the lifespan to zero if you don't want the particles to be born at all. Otherwise, if you give them a lifespan larger than zero and then kill them afterward, they will live for at least 1 frame. You can also increase the oversampling to insanely high (like 5, 50, 100 depends on your particles count) to kill most of the particles in-between frame, but you can still see some particles survive, maybe you could get away from it? Anyway, it would be better if you could tell us more about your ultimate goal. Ronald Quote Link to comment Share on other sites More sharing options...
3dbeing Posted December 23, 2011 Share Posted December 23, 2011 Hi Ronald, I think you are referring to life expectancy set to 0 on the birth node, whereas menoz is changing the lifespan (life[1]) in an age pop... Menoz, if you are trying to get your particles to live forever, set Age = 0 rather then Lifespan. the particle is born and it is assigned a lifespan based on life expectancy + (life variance * random(-1,1)) as set in the birth node. If you open up a details view you can see life[0], life[1]. life[1] is lifespan or how long, in seconds, that particle will live. life[0] is how long in seconds that particle has been alive or age. there is another local attribute you have access to which is $LIFE = life[1]/life[0]; a normalized age. I was off a bit in my original statement because the kill and age pop are working slightly different. The kill pop kills them on the next cook, whereas the age pop allows them to live for one additional frame. In the kill pop particles are born assigned a kill and die on the next cook, whereas in the age pop method particles are born assigned a lifespan of 0 but this frame holds the lifespan they were born with apparently, on the next frame they have lived longer than lifespan which is now 0 and therefore assigned a kill and die on the next frame. Quote Link to comment Share on other sites More sharing options...
MENOZ Posted December 23, 2011 Author Share Posted December 23, 2011 (edited) I want to emit particles form a texture. The only way I found is to kill the particles in areas where they aren't supposed to be. but with the kill sop I have to delete the remaining particles in sop. Instead it would be much better if -I could kill not in the current cook or better -I could specify where to emit particles instead of born and delete them. I want to emit with a texture, regardless of the resolution of the source mesh. I wanted to know why kill pop kills on next cook, and if this could be modified. thank you! Edited December 23, 2011 by MENOZ Quote Link to comment Share on other sites More sharing options...
mawi Posted December 23, 2011 Share Posted December 23, 2011 I want to emit particles form a texture. The only way I found is to kill the particles in areas where they aren't supposed to be. but with the kill sop I have to delete the remaining particles in sop. Instead it would be much better if -I could kill not in the current cook or better -I could specify where to emit particles instead of born and delete them. I want to emit with a texture, regardless of the resolution of the source mesh. I wanted to know why kill pop kills on next cook, and if this could be modified. thank you! Scatter points, assign texture, delete non wanted and emit from the ones left. Quote Link to comment Share on other sites More sharing options...
3dbeing Posted December 23, 2011 Share Posted December 23, 2011 In a source pop look at Birth Probability. If by texture you mean color, in birth probability you can use $CR. Although I think probability is a misnomer as it's a Min/Max integer of number of particles a point will birth on a given frame, the field may say it's a float, I think it's obvious how a point could never birth .5 particles... I usually put $CR in both fields, so wherever there is color above .5 a particle will be born and wherever there is color below .5 it will not. Quote Link to comment Share on other sites More sharing options...
MENOZ Posted December 24, 2011 Author Share Posted December 24, 2011 I don't want to pass by the scatter points step. I know it works, but I though that you would need a very dense point cloud if you want to emit high particle count from the object. also scatter should be updated at each frame to have a random "smpling" on the surface. Quote Link to comment Share on other sites More sharing options...
Nik S Posted January 4, 2012 Share Posted January 4, 2012 (edited) I don't want to pass by the scatter points step. I know it works, but I though that you would need a very dense point cloud if you want to emit high particle count from the object. also scatter should be updated at each frame to have a random "smpling" on the surface. Scatter around 50000 points then sim 20 times with a different seed setting on the scatter node... Could use takes or wedge or something? We have tools to do multi simulations but I'm sure with minimal effort you could figure it out. You could also just input $F*25/2 (or whatever) into the Random Seed parm to get a different number each frame, Edited January 5, 2012 by Nik S Quote Link to comment Share on other sites More sharing options...
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