Try hard coding OSX paths.

cmake/FindOGRE.cmake

@@ -356,7 +356,7 @@ set(OGRE_COMPONENT_SEARCH_PATH_DBG
 
 macro(ogre_find_component COMPONENT HEADER)
   findpkg_begin(OGRE_${COMPONENT})
-  find_path(OGRE_${COMPONENT}_INCLUDE_DIR NAMES ${HEADER} HINTS ${OGRE_INCLUDE_DIRS} ${OGRE_INCLUDE_DIR}/Ogre${COMPONENT} ${OGRE_PREFIX_SOURCE} PATH_SUFFIXES ${COMPONENT} OGRE/${COMPONENT} Components/${COMPONENT}/include)
+  find_path(OGRE_${COMPONENT}_INCLUDE_DIR NAMES ${HEADER} HINTS ${OGRE_INCLUDE_DIRS} ${OGRE_INCLUDE_DIR}/OGRE/${COMPONENT} ${OGRE_PREFIX_SOURCE} PATH_SUFFIXES ${COMPONENT} OGRE/${COMPONENT} Components/${COMPONENT}/include)
   set(OGRE_${COMPONENT}_LIBRARY_NAMES "Ogre${COMPONENT}${OGRE_LIB_SUFFIX}")
   get_debug_names(OGRE_${COMPONENT}_LIBRARY_NAMES)
   find_library(OGRE_${COMPONENT}_LIBRARY_REL NAMES ${OGRE_${COMPONENT}_LIBRARY_NAMES} HINTS ${OGRE_LIBRARY_DIR_REL} PATH_SUFFIXES "" "release" "relwithdebinfo" "minsizerel")
@@ -365,7 +365,7 @@ macro(ogre_find_component COMPONENT HEADER)
   findpkg_finish(OGRE_${COMPONENT})
   if (OGRE_${COMPONENT}_FOUND)
     if (APPLE)
-        include_directories("${OGRE_INCLUDE_DIR}/${COMPONENT}")
+      include_directories("${OGRE_INCLUDE_DIR}/OGRE/${COMPONENT}")
     endif()
     # find binaries
     if (NOT OGRE_STATIC)