size(500,500, P3D); //setup the screen
camera(-20,20,-20,0,0,0,0,0,1); //get a viewpoint
for(int x=-10; x<10; x++) //loop in three directions
  for(int y=-10; y<10; y++)
    for(int z=-10; z<10; z++)
      point(x,y,z);