ROS编译D435i过程中的问题及解决

请确保已经正确安装了ROS 、OPENCV3、realsense-viewer。（注意不要考虑OPENCV4）

编译出现第一个问题

`-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

– ~~ traversing 5 packages in topological order:
– ~~ - realsense2_camera_msgs (plain cmake)
– ~~ - realsense2_description (plain cmake)
– ~~ - ddynamic_reconfigure
– ~~ - realsense2_camera (plain cmake)
– ~~ - usb_cam
– ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CMake Error at /opt/ros/melodic/share/catkin/cmake/catkin_workspace.cmake:100 (message):`

指三个错误的包不能编译的意思？
问题是没有正确完成对realsense-ros的处理！
进入realsense-ros文件夹

cd ~/catkin_ws/src/realsense-ros/      
git checkout `git tag | sort -V | grep -P "^2.\d+\.\d+" | tail -1`
cd ~/catkin_ws
catkin_make clean            
catkin_make                   

编译出现第二个问题

CMake Error at /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
  Could not find a package configuration file provided by "OpenCV" with any
  of the following names:

    OpenCVConfig.cmake
    opencv-config.cmake

  Add the installation prefix of "OpenCV" to CMAKE_PREFIX_PATH or set
  "OpenCV_DIR" to a directory containing one of the above files.  If "OpenCV"
  provides a separate development package or SDK, be sure it has been
  installed.

指为找到OPENCV，需要在:~/catkin_ws/src/realsense-ros/realsense2_camera内的CMakeLists.txt内于find_package()上添加：set(OpenCV_DIR /usr/local/share/OpenCV/)