The camera setup is unfortunately, quite screwy.
The following code should, in my intepretation fo the reference, make a camera pan around the centre object (a ball with 3 axes), in a smooth circle.
However it does something weird, and I'm not quite sure how it's interpreting the values passed to it.
Code:
float a;
void setup()
{
size(600,600,P3D);
a=0;
}
void draw()
{
a+=0.01;
background(128);
//set camera "eye" x and y positions so they follow a circle radius 400 around point 0,0,0
//set camera "scene centre" to be 0,0,0
//set camrea "up" to be 0,1,0 , i.e. positive Y value = up;
camera(400.0*cos(a),0,400.0*sin(a),0.0,0.0,0.0,0.0,1.0,0.0);
//draw a sphere at 0,0,0 (no translate, so I assume 0,0,0...
noStroke();
fill(255);
sphere(10);
//draw 3 axes, form 0,0,0 along x, y and z axes.
beginShape(LINES);
stroke(255,0,0);
vertex(0,0,0);
vertex(100,0,0);
stroke(0,255,0);
vertex(0,0,0);
vertex(0,100,0);
stroke(0,0,255);
vertex(0,0,0);
vertex(0,0,100);
endShape();
//end result should, I think, be that the camera pans aroudn the ball and axes, keeping them centred.
}