title: cmake including h files from other directories
body: <p>I am having trouble including a test under a cmake project. My project is set out like this:</p>
  
  <pre><code>                                       TerrainMap
                                          /     \
                           PointAccumulator     heightQuadGrid
                                                  \
                                                   Test
  </code></pre>
  
  <p>In the TerrainMap Directory the CMakeLists.txt file simply outlines the cmake version the project name and includes the two sub directories. </p>
  
  <p>In heightQuadGrid the CMakeLists.txt looks like this:</p>
  
  <pre><code>cmake_minimum_required(VERSION 2.8)
  
  find_package(PCL 1.2 REQUIRED)
  find_package(OpenCV REQUIRED)
  
  include_directories(${PCL_INCLUDE_DIRS})
  link_directories(${PCL_LIBRARY_DIRS})
  add_definitions(${PCL_DEFINITIONS})
  
  add_library(heightQuadGrid heightQuadGrid.cpp)
  
  add_subdirectory(Test)
  </code></pre>
  
  <p>which as I understand makes a library called heightQuadGrid. The CMakeLists.txt in Test looks like this:</p>
  
  <pre><code>FIND_PACKAGE(PCL 1.2 REQUIRED)
  FIND_PACKAGE(OpenCV REQUIRED)
  FIND_PACKAGE(Boost COMPONENTS unit_test_framework REQUIRED)
  
  include_directories(${PCL_INCLUDE_DIRS})
  link_directories(${PCL_LIBRARY_DIRS})
  add_definitions(${PCL_DEFINITIONS} )
  
  link_libraries(heightQuadGrid)
  
  add_executable(heightQuadTreeTest heightQuadGridTest.cpp)
  target_link_libraries (heightQuadTreeTest heightQuadGrid ${PCL_LIBRARIES} ${OpenCV_LIBS} ${Boost_UNIT_TEST_FRAMEWORK_LIBRARY})
  </code></pre>
  
  <p>And finally the cpp file heightQuadGridTest.cpp has this include:</p>
  
  <pre><code>#include &lt;heightQuadGrid/heightQuadGrid.h&gt;
  </code></pre>
  
  <p>The cmake works correctly but when i go to make the project it tells me that it cannot find heightQuadGrid/heightQuadGrid.h </p>
  
  <p>Whats the deal as I have seen a very similar approach in another working project?</p>