code: @Override
  	public Point3d[] getVertices() {
  		double x = 0.5 * width;
  		double y = 0.5 * height;
  		double z = 0.5 * length;
  		Point3d[] vertices = new Point3d[8];
  		vertices[0] = new Point3d(-x, -y,  z);
  		vertices[1] = new Point3d(-x,  y,  z);
  		vertices[2] = new Point3d( x,  y,  z);
  		vertices[3] = new Point3d( x, -y,  z);
  		vertices[4] = new Point3d(-x, -y, -z);
  		vertices[5] = new Point3d(-x,  y, -z);
  		vertices[6] = new Point3d( x,  y, -z);
  		vertices[7] = new Point3d( x, -y, -z);
  
  		return vertices;
  	}
docs: Returns the vertices of an n-fold polygon of given radius and center
  @param n
  @param radius
  @param center
  @return