Writing a CMakeLists.txt for ROS - cmake

Question

I am new to ROS (Indigo), and I want to write a C++ program to use the MoveIt! package.
However, I am confused as to what I need to have in my CMakeLists.txt file, such that the header and library files can be found.
For example, here is the file so far:
cmake_minimum_required(VERSION 2.8.1)
project(MicoMoveIt)
set(CMAKE_CXX_FLAGS "-std=c++11")
file(GLOB srcs *.cpp)
include_directories(/opt/ros/indigo/include)
link_directories(/opt/ros/indigo/lib)
add_executable(${PROJECT_NAME} ${srcs})
And my main.cpp file is:
#include <ros/ros.h>
#include <moveit/move_group_interface/move_group.h>
int main()
{
moveit::planning_interface::MoveGroup group("right_arm");
return 0;
}
But compiling this gives me the error:
/opt/ros/indigo/include/moveit/robot_model/joint_model.h:47: error: Eigen/Geometry: No such file or directory
#include <Eigen/Geometry>
^
So, I need to specify where to find these Eigen header files. But given that Eigen is a dependency of MoveIt!, then I shouldn't have to manually include all these header file directories.
How should I be writing the CMakeLists.txt file so that all header and library directories of dependencies are included?

Answer 1

Try with this changes:
cmake_minimum_required(VERSION 2.8.3)
project(<project_name>)
set(CMAKE_CXX_FLAGS "-std=c++11")
find_package(catkin REQUIRED COMPONENTS
<other_packages_you_need>
moveit_ros_planning_interface
)
catkin_package(CATKIN_DEPENDS)
include_directories(include ${catkin_INCLUDE_DIRS})
set(BINNAME <executable_name>)
set(SOURCES <cpp_source_files>)
add_executable (${BINNAME} ${SOURCES})
target_link_libraries(${BINNAME} ${catkin_LIBRARIES})
The key factor for your problem is the inclusion of package moveit_ros_planning_interface in the find_package() directive. Everytime you have to build some code, you have to add every package dependancies to your project (in this case you need the moveit interface package). Notice that the package.xml file plays a crucial role too.
Lastly you have to tell the linker to retrieve and link the libraries you are using in your project. To do so use target_link_libraries() and the useful catkin_LIBRARIES variable which almost does what you expected (you could manually add libraries, but it could be messy in big projects).
Have a look here and here for more info.
EDIT: in this case you do not need the link_directories() directive, which has to be used only when the linker has to know where to retrieve the external library.