linking to a custom library using cmake - c++

Question

I have two cmake files that build a directory and then try to compile an example that uses that library. The content of the first CMakeLists.txt file stored at the project root ${CMAKE_SOURCE_DIR} is:
cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
project("lsd_point_pair")
SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
SET(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)
#Note: Eclipse automatically picks up include paths with this on!
SET(CMAKE_VERBOSE_MAKEFILE ON)
SET(CMAKE_CXX_FLAGS "-g")
find_package(PCL 1.7 REQUIRED)
include_directories(${PCL_INCLUDE_DIRS})
link_directories(${PCL_LIBRARY_DIRS})
add_definitions(${PCL_DEFINITIONS})
set(BOOST_LIBS program_options)
find_package(Boost COMPONENTS ${BOOST_LIBS} REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARY_DIRS})
MESSAGE(" Boost_LIBRARIES: ${Boost_LIBRARIES}")
include_directories(${PROJECT_BINARY_DIR})
link_directories(${PROJECT_BINARY_DIR}/lib})
add_library(lsd_obj_rec_ransac lsd_obj_rec_ransac.cpp lsd_obj_rec_ransac.h lsd_point_pair_model_library.cpp lsd_point_pair_model_library.h ndim_voxel_structure.h orr_octree_cloud.h orr_octree_cloud.cpp)
target_link_libraries(lsd_obj_rec_ransac ${PCL_LIBRARIES} ${Boost_LIBRARIES})
######## subdirectories #########
add_subdirectory(examples)
In ${CMAKE_SOURCE_DIR}/examples I have the following CMakeLists.txt file:
add_executable(example_pcl_lsd_point_pair example_pcl_lsd_point_pair.cpp)
target_link_libraries(example_pcl_lsd_point_pair lsd_obj_rec_ransac ${Boost_LIBRARIES} ${PCL_LIBRARIES})
After successfully running cmake I run make and I get the linking errors:
CMakeFiles/example_pcl_lsd_point_pair.dir/example_pcl_lsd_point_pair.cpp.o: In function `~LSDObjRecRANSAC':
make[2]: Leaving directory `/media/Data/Documents/Grad/research/Projects/LSDPointPairs/qtcreator-build'
make[1]: Leaving directory `/media/Data/Documents/Grad/research/Projects/LSDPointPairs/qtcreator-build'
/home/mustafa/projects/LSDPointPairs/examples/../lsd_obj_rec_ransac.h:44: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
/home/mustafa/projects/LSDPointPairs/examples/../lsd_obj_rec_ransac.h:44: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
../lib/liblsd_obj_rec_ransac.a(lsd_obj_rec_ransac.cpp.o): In function `LSDObjRecRANSAC':
/home/mustafa/projects/LSDPointPairs/lsd_obj_rec_ransac.cpp:18: undefined reference to `pcl::recognition::LSDPointPairModelLibrary::LSDPointPairModelLibrary(float, float, float)'
/home/mustafa/projects/LSDPointPairs/lsd_obj_rec_ransac.cpp:18: undefined reference to `pcl::recognition::ORROctreeCloud::ORROctreeCloud()'
/home/mustafa/projects/LSDPointPairs/lsd_obj_rec_ransac.cpp:18: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
../lib/liblsd_obj_rec_ransac.a(lsd_point_pair_model_library.cpp.o): In function `LSDPointPairModel':
/home/mustafa/projects/LSDPointPairs/lsd_point_pair_model_library.h:36: undefined reference to `pcl::recognition::ORROctreeCloud::ORROctreeCloud()'
/home/mustafa/projects/LSDPointPairs/lsd_point_pair_model_library.h:36: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
../lib/liblsd_obj_rec_ransac.a(lsd_point_pair_model_library.cpp.o): In function `~LSDPointPairModel':
/home/mustafa/projects/LSDPointPairs/lsd_point_pair_model_library.h:27: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
/home/mustafa/projects/LSDPointPairs/lsd_point_pair_model_library.h:27: undefined reference to `pcl::recognition::ORROctreeCloud::~ORROctreeCloud()'
collect2: ld returned 1 exit status
make[2]: *** [bin/example_pcl_lsd_point_pair] Error 1
make[1]: *** [examples/CMakeFiles/example_pcl_lsd_point_pair.dir/all] Error 2
make: *** [all] Error 2
The library successfully gets built because I see the liblsd_obj_rec_ransac.a file gets generated. But the problem happens when trying to compile the example. What am I doing wrong?