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Index › Programming Questions & Help › Programs › Problem with Learning Example, Particles
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Problem with Learning Example, Particles (Read 572 times)
jazz
Problem with Learning Example, Particles
May 15th, 2009, 10:16pm  
Hello, i tried to work on some examples by dan Shiffman to understand them but i have some problem with this  Code : http://processing.org/learning/topics/simpleparticlesystem.html
Could somebody tell me where exactly the amout of particles is insert? there is a "num" but changes dont effekt anything. I just get alot of them at first but after that the amout is still the same. I dont get it...
Could you explain it to me?
Thank you!
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ben_hem
Re: Problem with Learning Example, Particles
Reply #1 - May 16th, 2009, 1:19am  
Because

for (int i = 0; i < num; i++) {
  particles.add(new Particle(origin));
}

happens within the ParticleSystem construction, it only happens once (during setup, when constructed).

Try putting this into draw() instead:

for (int i = 0; i < 20; i++) {
  ps.addParticle(mouseX,mouseY);
}

--Ben
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adam sax
Re: Problem with Learning Example, Particles
Reply #2 - May 23rd, 2009, 6:25pm  
actually it would be slightly different because Particle expects a PVector in it's constructor.

So it would be more like

Code:

for (int i = 0; i < 20; i++) {
  ps.addParticle(new PVector(mouseX,mouseY));
}


but Ben had the right idea.

-adam
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