hello,

i'm really sorry if the subject had been discussed before but a quick search returned me nothing.

Actually i'm still learning processing and i'm trying to map a simple particle system to a webcam image. I'd like to map each particles to each pixels and that's my pb.

I work with a 320x240 resolution so i need something like 320*240 particles i guess or maybe i can map the particles in a more clever way ?  And i don't really know how to replace each pixel by each particles.

I'm trying that with the JMyron library using the pixel_fun1 example and trying to mess it but i'm quite stuck with that actually.

Thx by advance and thx to you all for making such great things.

It might be fairly straight forwards to do, if you've written a  nice particle class, but slightly more difficult if you're just using arrays.

If you want to have a fixed set of particles (320x240 of them) and update them based on the webcam, then it should be easy, and would go something like:

Code:

myParticleClass Particles=new myParticleClass[320*240];

//in setup()
for(int i=0;i<Particles.length;i++)
{
  Particles[i]=new Particle(i%320,i/320,0); 
// assuming you've got arguments of x position, y position, colour
}


//in draw
webCamImage.loadPixels();
for(int i=0;i<webCamImage.pixels.length;i++)
{
  //update the colour of the particle that 
  // represents this pixel
  Particles[i].colour=webCamImage.pixels[i];
} 

If you're just using a bunch of arrays to store them it's slightly more complex setup, but the update is almost the same:

Code:

float[] particlesX=new float[320*240];
float[] particlesY=new float[320*240];
color[] particlesColor=new color[320*240];

//in setup
for(int i=0;i<320*240;i++)
{
  particlesX[i]=i%320;
  particlesY[i]=i/320;
  particlesColor[i]=0; // start off black since no image yet
}

//in draw
webCamImage.loadPixels();
for(int i=0;i<webCamImage.pixels.length;i++)
{
  particlesColor[i]=webCamImage.pixels[i];
} 

Of course you'll have to do any movement code for yourself, but this should at least let you assign the colours to the particles for whatever use you want.