Dependencies
1、OpenCV(http://docs.opencv.org/master/d9/df8/tutorial_root.html)
2、PCL(http://pointclouds.org/downloads/)
3、OpenMP(http://www.openmp.org/)
4、rviz(http://wiki.ros.org/rviz)

Compile
You should put this project under your ROS work space, such as your_ros_path/src/
cd your_ros_path
catkin_make

Usage
1、 roslaunch grid_ndt receLaunch.launch
2、 roslaunch grid_ndt ocLaunch.launch
  The experimental data (*.pcd) can be attained in https://pan.baidu.com/s/1jAkX8rIEB9MltmE6Rqz32Q with code 4itv and the corresponding parameters can be attained in /launch/parameters.txt.
  For visualization, the rviz should subscribe the top "initial_marker_array", "traversibility_marker_array" and "route_marker_array".