三次元の線を重ねる

/**
* 3D Lines
*
* @author aa_debdeb
* @date 2015/11/28
*/

float gray;
float radious;
float theta1;
float theta2;

int grayStep;
float radiousNoise;
float theta1Noise;
float theta2Noise;

void setup(){
  size(500, 500, P3D);
  background(255);
  smooth();
  frameRate(30);
  
  radious =  300;
  theta1 = PI;
  theta2 = PI;
  
  grayStep = 1;
  radiousNoise = random(100);
  theta1Noise = random(100);
  theta2Noise = random(100);
}

void draw(){
   
  radious = 250 + map(noise(radiousNoise + frameCount * 0.01), 0, 1, -75, 75);
  theta1 += map(noise(theta1Noise + frameCount * 0.01), 0, 1, -PI / 32, PI / 32);
  theta2 += map(noise(theta2Noise + frameCount * 0.01), 0, 1, -PI / 32, PI / 32);
  
  if(theta1 < 0){
    theta1 += TWO_PI;
  } else if(theta1 >= TWO_PI){
    theta1 -= TWO_PI;
  }
  if(theta2 < 0){
    theta2 += TWO_PI;
  } else if(theta2 >= TWO_PI){
    theta2 -= TWO_PI;
  }
  
  gray += grayStep;
  if(gray < 0){
    gray = 0;
    grayStep *= -1;
  } else if(gray > 255){
    gray = 255;
    grayStep *= -1;
  }
    
  float x1 = radious * sin(theta1) * cos(theta2);
  float y1 = radious * sin(theta1) * sin(theta2);
  float z1 = radious * cos(theta1) * cos(theta2);
  float x2 = -x1;
  float y2 = -y1;
  float z2 = -z1;
  
  stroke(gray);
  translate(width/2, height/2);
  line(x1, y1, z1, x2, y2, z2);
}