title: Linking errors with qt pcl and vtk
body: <p>I am trying to compile the PCL tutorial described <a href="http://pointclouds.org/documentation/tutorials/qt_visualizer.php" rel="nofollow">here</a> and I am facing these linking errors.</p>
  
  <blockquote>
    <p>Linking CXX executable pcl_visualizer usr/lib/libpq.so.5: undefined
    reference to <code>SSL_get_peer_certificate@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    </code>TIFFReadDirectory@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined
    reference to <code>CRYPTO_num_locks@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to
    </code>SSL_CTX_use_certificate_chain_file@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    <code>TIFFIsTiled@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined reference to
    </code>SSL_use_certificate_file@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to <code>ENGINE_free@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to</code>OPENSSL_config@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to <code>SSL_get_error@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    </code>SSL_use_PrivateKey_file@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to <code>X509_STORE_load_locations@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    </code>TIFFDefaultStripSize@LIBTIFF_4.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to <code>TIFFReadTile@LIBTIFF_4.0' usr/lib/libpq.so.5:
    undefined reference to</code>SSL_set_ex_data@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    <code>TIFFWriteScanline@LIBTIFF_4.0' usr/lib/libvtkIO.so.5.8.0: undefined
    reference to</code>_TIFFfree@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined
    reference to <code>SSL_read@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to</code>TIFFGetField@LIBTIFF_4.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    <code>TIFFScanlineSize@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined reference
    to</code>X509_STORE_set_flags@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to <code>SSLv23_method@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to</code>ENGINE_load_private_key@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    <code>X509_get_subject_name@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to</code>CRYPTO_set_id_callback@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    <code>TIFFClose@LIBTIFF_4.0' usr/lib/libvtkIO.so.5.8.0: undefined reference
    to</code>TIFFClientOpen@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined
    reference to <code>SSL_CTX_new@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to</code>SSL_CTX_get_cert_store@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    <code>SSL_check_private_key@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to</code>TIFFGetFieldDefaulted@LIBTIFF_4.0'
    usr/lib/libpq.so.5: undefined reference to
    <code>ENGINE_by_id@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0: undefined
    reference to</code>TIFFNumberOfDirectories@LIBTIFF_4.0' usr/lib/libpq.so.5:
    undefined reference to <code>ERR_get_error@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    </code>CRYPTO_set_locking_callback@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to <code>SSL_load_error_strings@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to</code>SSL_new@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    <code>X509_NAME_get_text_by_NID@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to</code>TIFFOpen@LIBTIFF_4.0' usr/lib/libpq.so.5:
    undefined reference to <code>SSL_write@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to</code>X509_free@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to <code>SSL_CTX_load_verify_locations@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    </code>TIFFReadRGBAImage@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined
    reference to <code>SSL_free@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to</code>SSL_ctrl@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to <code>TIFFSetField@LIBTIFF_4.0' usr/lib/libpq.so.5:
    undefined reference to</code>SSL_set_verify@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to <code>ENGINE_init@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to</code>SSL_set_fd@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to <code>SSL_connect@OPENSSL_1.0.0'
    usr/lib/libpq.so.5: undefined reference to
    </code>ERR_reason_error_string@OPENSSL_1.0.0' usr/lib/libpq.so.5: undefined
    reference to <code>SSL_CTX_ctrl@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to</code>SSL_pending@OPENSSL_1.0.0' usr/lib/libpq.so.5:
    undefined reference to <code>SSL_use_PrivateKey@OPENSSL_1.0.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    </code>TIFFSetWarningHandler@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined
    reference to <code>ENGINE_finish@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to</code>TIFFSetErrorHandler@LIBTIFF_4.0'
    usr/lib/libvtkIO.so.5.8.0: undefined reference to
    <code>_TIFFmalloc@LIBTIFF_4.0' usr/lib/libpq.so.5: undefined reference to
    </code>SSL_library_init@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0: undefined
    reference to <code>TIFFSetDirectory@LIBTIFF_4.0' usr/lib/libvtkIO.so.5.8.0:
    undefined reference to</code>TIFFReadScanline@LIBTIFF_4.0'
    usr/lib/libpq.so.5: undefined reference to
    <code>SSL_shutdown@OPENSSL_1.0.0' usr/lib/libvtkIO.so.5.8.0: undefined
    reference to</code>TIFFNumberOfTiles@LIBTIFF_4.0' collect2: error: ld
    returned 1 exit status make[2]: <strong>* [pcl_visualizer] Error 1 make<a href="http://pointclouds.org/documentation/tutorials/qt_visualizer.php" rel="nofollow">1</a>:
    *</strong> [CMakeFiles/pcl_visualizer.dir/all] Error 2 make: *** [all] Error 2</p>
  </blockquote>
  
  <p>The CmakeList file is define as follow:</p>
  
  <pre><code>cmake_minimum_required (VERSION 2.6 FATAL_ERROR)
  
  project      (pcl-visualizer)
  find_package (Qt4 REQUIRED)
  find_package (VTK REQUIRED)
  find_package (PCL 1.7.1 REQUIRED)
  
  include_directories (${PCL_INCLUDE_DIRS})
  link_directories    (${PCL_LIBRARY_DIRS})
  add_definitions     (${PCL_DEFINITIONS})
  
  set  (project_SOURCES main.cpp pclviewer.cpp)
  set  (project_HEADERS pclviewer.h)
  set  (project_FORMS   pclviewer.ui)
  set  (VTK_LIBRARIES   vtkRendering vtkGraphics vtkHybrid QVTK)
  
  QT4_WRAP_CPP (project_HEADERS_MOC   ${project_HEADERS})
  QT4_WRAP_UI  (project_FORMS_HEADERS ${project_FORMS})
  
  INCLUDE         (${QT_USE_FILE})
  ADD_DEFINITIONS (${QT_DEFINITIONS})
  
  ADD_EXECUTABLE  (pcl_visualizer ${project_SOURCES}
                                  ${project_FORMS_HEADERS}
                                  ${project_HEADERS_MOC})
  
  TARGET_LINK_LIBRARIES (pcl_visualizer ${QT_LIBRARIES} ${PCL_LIBRARIES} ${VTK_LIBRARIES})
  </code></pre>
  
  <p>Is there anything missing in the CMakeList file?</p>