"I made several modifications:
* The cause of my errors was that my OSG source directory path contains spaces. To fix this issue I wrapped all paths with quotes, as stated in doxygen documentation.
* I also received some warning messages about deprecated doxygen settings, which I fixed by updating the doxygen file, i.e. running \u2018doxygen \u2013u doxygen.cmake\u2018. By running this command deprecated doxygen options are removed, some option comments have changed and quite some options have been added (I kept their default settings unless mentioned).
* I was surprised to find that the doxygen OUTPUT_DIRECTORY was set to \u201c${OpenSceneGraph_SOURCE_DIR}/doc\u201d, which does not seem appropriate for out of source builds; I changed this to \u201c${OpenSceneGraph_BINARY_DIR}/doc\u201d. (On the other hand, maybe a cmake selectable option should be given to the user?)
* Fixed two warnings I received about unexpected end-of-list-markers in \u2018osg\AnimationPath and \u2018osgUtil\CullVisitor due to excess trailing points in comments.
* Fixed a warning in osgWidget\StyleInterface due to an #include directive (strangely) placed inside a namespace.
* Fixed a warning in osg\Camera due to the META_Object macro that confused doxygen. Adding a semi-colon fixed this.
* Removed auto_Mainpage from the INCLUDE option, because I am positive that this file does not belong there; It never generated useful documentation anyway.
* I added the OSG version number environment variable to the PROJECT_NUMBER option so that the version number is now shown on the main page of generated documentation (e.g. index.html).
* Changed option FULL_PATH_NAMES to YES, but made sure STRIP_FROM_PATH stripped the absolute path until the include dir. This fixed an issue that created mangled names for identical filenames in different directories. E.g. osg/Export and osgDB/Export are now correctly named.
* Changed option SHOW_DIRECTORIES to yes, which is a case of preference I guess.
"
