anchor.diff:      ++ lib.optional tiffSupport libtiff
       ++ lib.optional gdalSupport gdal
       ++ lib.optional curlSupport curl
  -    ++ lib.optional colladaSupport opencollada
  +    ++ lib.optional colladaSupport collada-dom
       ++ lib.optional opencascadeSupport opencascade
       ++ lib.optional ffmpegSupport ffmpeg
       ++ lib.optional nvttSupport nvidia-texture-tools
  
positive.code:   tiffSupport ? true, libtiff,
    gdalSupport ? false, gdal,
    curlSupport ? true, curl,
    colladaSupport ? false, opencollada,
    opencascadeSupport ? false, opencascade,
    ffmpegSupport ? false, ffmpeg,
    nvttSupport ? false, nvidia-texture-tools,
  
negative.code:     ++ lib.optional lasSupport libLAS
      ++ lib.optional luaSupport lua
      ++ lib.optional sdlSupport SDL2
      ++ lib.optional restSupport asio
      ++ lib.optionals withExamples [ fltk wxGTK ]
      ++ lib.optionals stdenv.isDarwin [ AGL Carbon Cocoa Foundation ]
      ++ lib.optional (restSupport || colladaSupport) boost
    ;
  
    cmakeFlags = lib.optional (!withApps) "-DBUILD_OSG_APPLICATIONS=OFF" ++ lib.optional withExamples "-DBUILD_OSG_EXAMPLES=ON";
  