Individual vertices in a THREE.Geometry
instance are accessible via its vertices
array.
I found a tutorial that explains how to animate particles in a particle system independently. Here's the relevant section of the update
animation loop with some minor modifications.
function update() {
var pCount = particleCount;
while (pCount--) {
var particle = particles.vertices[pCount];
if (particle.position.y < -200) {
particle.position.y = 200;
particle.velocity.y = 0;
}
particle.velocity.y -= Math.random() * .1;
particle.position.addSelf(particle.velocity);
}
particleSystem.geometry.__dirtyVertices = true;
renderer.render(scene, camera);
requestAnimFrame(update);
}