Three.js粒子形成形状

Question

I've been following this tutorial ( http://creativejs.com/tutorials/three-js-part-1-make-a-star-field/ ) and everything is going fine, but I'd like to know how I can modify the script so then there's some form of callback when the particle reaches the end. I've modified the code in the tutorial so it's reversed the way the particles are moving.

What I'm wanting to try and create is a load of particles coming together to form a square, is it possible from using the code in the tutorial as a start and build on top of that or should I look elsewhere and start over?

Thanks in advance.

Answer 1

Wouldn't it be easy if you create the same amount of particles as the model's amount of vertices, and move the particles towards the vertices' position?

var p = emitter.geometry.vertices;  // the vertices (particles) of your particle emitter
var m = model.geometry.vertices;    // the vertices of the target model

for(var i in p) {
    p[i].x = (p[i].x + m[i].x) / 2;
    p[i].y = (p[i].y + m[i].y) / 2;
    p[i].z = (p[i].z + m[i].z) / 2;
}