code: function (plane) {
          // Distance to plane
          var d = vec3.dot(plane.normal.array, this.direction.array);
          vec3.scaleAndAdd(this.direction.array, this.direction.array, plane.normal.array, -d * 2);
          this.direction._dirty = true;
      }
docs: Mirror the ray against plane
  @param  {clay.Plane} plane