Processing: Creative Coding and Computational Art

PROCESSING: CREATIVE CODING AND COMPUTATIONAL ART
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Figure 13-9. Cubes Contained Within a Cube sketch
This example is long—but again, it’s stuff you’ve looked at before. The most complex part
of the sketch is the following code snippet, within the for loop of the draw() function:
pushMatrix();
translate(x[i], y[i], z[i]);
rotateX(frameCount*PI/xRot[i]);
rotateY(frameCount*PI/yRot[i]);
rotateX(frameCount*PI/zRot[i]);
noStroke();
c[i].create(quadBG[i]);
x[i]+=xSpeed[i];
y[i]+=ySpeed[i];
z[i]+=zSpeed[i];
popMatrix();
It is sometimes confusing, when using the pushMatrix() and popMatrix() functions, to
determine what commands need to be called between them. Since I’m using a loop to
process an array of items, I need to make sure that each transformation only affects its
respective item; otherwise, the transformations will become cumulative, so objects stored
later in the array will be affected much more than the earlier ones. It is helpful to break
down the last example by commenting out the pushMatrix() and popMatrix() calls and
then rerunning the sketch to see the effect. In addition, I recommend playing with some
of the values in the sketch, especially the variables in the following code:
int cubies = 50;
float bounds = 300;
float cubieSize = random(5, 15);
xSpeed[i] = random(-2, 2);
ySpeed[i] = random(-2, 2);
zSpeed[i] = random(-2, 2);