int side=50; 
int sx=side+1; 
int sy=side+1; 
int sz=side+1; 
int hsx=int(sx/2.0f); 
int hsy=int(sy/2.0f); 
int hsz=int(sz/2.0f); 
int nc=150; 
float[][][] points=new float[sx][sy][sz]; 
float[][] transDown=new float[sx][sz]; 
float[][] transUp=new float[sx][sz]; 
float[][] transLeft=new float[sy][sz]; 
float[][] transRight=new float[sy][sz];
float[][] transFront=new float[sx][sy]; 
float[][] transBack=new float[sx][sy]; 
int[][][] volumes=new int[nc][2][3]; 
float ct=0.5; 
float ay=0.50; 
float ry=0.005; 
float ax=0.2; 
float factor=1.0; 
float scx=150.0/sx;
float scy=150.0/sy; 
float scz=150.0/sz; 

void setup(){
  size(800,290);
  background(255);
  noFill();
  framerate(18);
  setupVolume();
}

void draw(){
  factor=1.0;
  calculate(); 
  drawProj();
  filter(BLUR,5);
  drawProj();
  noLoop();
}

void keyReleased(){
  background(255);
  setupVolume();
  loop();
}

void mouseReleased(){
  background(255);
  setupVolume();
  loop();
}

void setupVolume(){
  volumes[0][0][0]=1;
  volumes[0][1][0]= side;
  volumes[0][0][1]=side-1;
  volumes[0][1][1]= side;
  volumes[0][0][2]=1;
  volumes[0][1][2]= side;
  volumes[1][0][0]=1;
  volumes[1][1][0]= side;
  volumes[1][0][1]=1;
  volumes[1][1][1]= 2;
  volumes[1][0][2]=1;
  volumes[1][1][2]= side;
  for(int c=2; c<nc; c++){
    for(int i=0;i<3;i++){
      volumes[c][0][i]=1+int(random(side));
      volumes[c][1][i]= volumes[c][0][i]+int(random(side-volumes[c][0][i]));
    }
  }
}

void calculate(){
  for(int i=0;i<sx;i++){
    for(int j=0;j<sy;j++){
      for(int k=0;k<sz;k++){
        points[i][j][k]=0.0f;
        transDown[i][k]=0.0f;
        transUp[i][k]=0.0f;
        transLeft[j][k]=0.0f;
        transRight[j][k]=0.0f;
        transFront[i][j]=0.0f;
        transBack[i][j]=0.0f;
      }
    }
  }

  for(int c=0;c<nc;c++){ 
    for(int i=volumes[c][0][0];i<volumes[c][1][0];i++){
      for(int j=volumes[c][0][1];j<volumes[c][1][1];j++){
        for(int k=volumes[c][0][2];k<volumes[c][1][2];k++){
          points[i][j][k]+=factor;
        }
      }
    }
    factor*=-1.0;
  }

  for(int i=0;i<sx;i++){
    for(int j=2;j<sy-2;j++){
      for(int k=0;k<sz;k++){
        if (points[i][j][k]>0) transDown[i][k]+=points[i][j][k] ;
        if (points[i][j][k]<0) transUp[i][k]-=points[i][j][k] ;
        if (points[i][j][k]>0) transLeft[j][k]+=points[i][j][k] ;
        if (points[i][j][k]<0) transRight[j][k]-=points[i][j][k] ;
        if (points[i][j][k]>0) transFront[i][j]+=points[i][j][k] ;
        if (points[i][j][k]<0) transBack[i][j]-=points[i][j][k] ;
      }
    }
  }
}

void drawProj(){//draw projections on bottom or top platform 
  noStroke();
  fill(230,60);
  int dx,dy;
  float sc=4.4;

  dx=35+110;
  dy=145;
  pushMatrix();
  translate(dx,dy);
  pushMatrix();
  rotate(random(PI));
  beginShape(QUADS);
  for(int k=1;k<sz-1;k++){
    for(int i=1;i<sx-1;i++){
      fill(0,0,0,transDown[i][k]*5);
      vertex(sc*(i-25),sc*(k-25));
      vertex(sc*(i+1-25),sc*(k-25));
      vertex(sc*(i+1-25),sc*(k+1-25));
      vertex(sc*(i-25),sc*(k+1-25));
    }
  }
  endShape();
  popMatrix();
  popMatrix();

  dx+=255;

  pushMatrix();
  translate(dx,dy);
  pushMatrix();
  rotate(random(PI));
  beginShape(QUADS);
  for(int k=1;k<sz-1;k++){
    for(int j=1;j<sy-1;j++){
      fill(0,0,0,int(transLeft[j][k]*5));
      vertex(sc*(k-25),sc*(j-25));
      vertex(sc*(k+1-25),sc*(j-25));
      vertex(sc*(k+1-25),sc*(j+1-25));
      vertex(sc*(k-25),sc*(j+1-25));
    }
  }
  endShape();
  popMatrix();
  popMatrix();

  dx+=255;

  pushMatrix();
  translate(dx,dy);
  pushMatrix();
  rotate(random(PI));
  beginShape(QUADS);
  for(int j=1;j<sy-1;j++){
    for(int i=1;i<sx-1;i++){
      fill(0,0,0,int(transFront[i][j]*5));
      vertex(sc*(i-25),sc*(j-25));
      vertex(sc*(i+1-25),sc*(j-25));
      vertex(sc*(i+1-25),sc*(j+1-25));
      vertex(sc*(i-25),sc*(j+1-25));
    }
  }
  endShape();
  popMatrix();
  popMatrix();



}


boolean between(float value, float limit1, float limit2){
  return (((value<=limit1)&&(value>limit2))||((value<=limit2)&&(value>limit1)));
}

float ruleOfThree(float x1, float x2, float x3, float y1, float y2){// if x1 maps to y1, and x2 maps to y2, find y3 linearly corresponding to x3
  return(y1 + (y2-y1)/(x2-x1)*(x3-x1));
}