Method localNormal

isis/src/base/objs/ShapeModel/ShapeModel.cpp:459–467

* Returns the local surface normal at the current intersection point. * Note: This method will throw an error if the normal doesn't exist. Use the * hasLocalNormal() method to verify before calling this method. * * @see hasLocalNormal() * * @return A local surface normal vector, if it exists. */

   * @return A local surface normal vector, if it exists.
   */
  std::vector<double> ShapeModel::localNormal() {
    if (m_hasLocalNormal ) {
      return m_localNormal;
    }
    else {
      QString message = "The local normal has not been computed.";
      throw IException(IException::Unknown, message, _FILEINFO_);
    }
  }

/**
 * @brief Default occulsion implementation