RTABMapConfig.cmake: added find VTK if vtkGUISupportQt target is required

CMakeLists.txt

@@ -412,8 +412,11 @@ ELSE()
    SET(CONF_DEPENDENCIES ${CONF_DEPENDENCIES} ${OCTOMAP_LIBRARIES}) 
 ENDIF()
 IF(ADD_VTK_GUI_SUPPORT_QT_TO_CONF)
+   SET(CONF_VTK_QT true)
    SET(CONF_DEPENDENCIES ${CONF_DEPENDENCIES} vtkGUISupportQt)
-ENDIF(ADD_VTK_GUI_SUPPORT_QT_TO_CONF)
+ELSE()
+   SET(CONF_VTK_QT false)
+ENDIF()
 IF(NOT (OpenCV_FOUND AND OpenCV_VERSION_MAJOR EQUAL 3))
    SET(OPENCV3 "//")
 ENDIF(NOT (OpenCV_FOUND AND OpenCV_VERSION_MAJOR EQUAL 3))

RTABMapConfig.cmake.in

@@ -62,6 +62,9 @@ if(@CONF_WITH_GUI@)
 endif(@CONF_WITH_GUI@)
 
 # Dependencies
+if(@CONF_VTK_QT@)
+   find_package(VTK COMPONENTS vtkGUISupportQt NO_MODULE) # to define vtkGUISupportQt target
+endif(@CONF_VTK_QT@)
 set(RTABMap_LIBRARIES ${RTABMap_LIBRARIES} @CONF_DEPENDENCIES@)
 
 #backward compatibilities