Processing: Creative Coding and Computational Art

Figure 11-25. 1D Collision Using Conservation of
Momentum sketch
Try running the sketch a few times and changing the radius of one of the balls. The greater
the difference between the two radii, the more obvious the effect of the conservation of
momentum will be.
2D collisions
Now that we got most of the easy stuff over with (I’m winking, don’t worry), we’ll tackle
the holy grail of collisions: non-orthogonal 2D collisions. In actuality, you already know
how to do this (well, sort of). I’ll be using the same coordinate rotation approach I used for
the Asteroid Shower sketch. The main difference is that there are now two objects colliding
(shown in Figure 11-26).
The main sketch tab reuses much of the existing code from the previous example, with the
changes shown in bold, as follows:
// Main Sketch Tab
// 2D Collision Using Conservation of Momentum
Ball[] balls = {
new Ball(100, 400, 10), new Ball(700, 400, 40) };
Vect2D[] vels = {
new Vect2D(4.3, -2.7), new Vect2D(-3.3, .95) };
void setup(){
size(400, 400);
smooth();
noStroke();
}
void draw(){
background(255);
fill(150);
for (int i=0; i