code: public void translate(double dx, double dy, double dz) {
  		// Compute the reference point for the plane
      	// (usefull for translation)
      	Point3f refPoint = (Point3f) getPivot();
      	
      	// a.x + b.y + c.z + d = 0
      	// where (x,y,z) is the translation point
      	setPivot(refPoint.getX()+dx,refPoint.getY()+dy,refPoint.getZ()+dz);
  	}
docs: Translate the pivot point of the plane.
  
  @param dx the translation to apply.
  @param dy the translation to apply.
  @param dz the translation to apply.