import processing.opengl.*;

void setup(){
  smooth();
 size(500,500,OPENGL); 
 camera(0,0,-300,0,0,0,0,1,0);
}

void draw(){
  setcam();
  background(0);
  box(100,100,100);
  /*beginShape();
  vertex(0,0,0);
  vertex(0,100,0);
  vertex(100,100,-200);
  vertex(100,0,0);
  endShape();*/
}

void setcam(){
 camera(mouseX-250,250-mouseY,-300,0,0,0,0,1,0); 
}