osgb文件过大，可以通过Compressor=zlib对纹理进行压缩

osg::ref_ptr<osgDB::ReaderWriter::Options> options = new osgDB::ReaderWriter::Options;

options->setOptionString("Compressor=zlib");          // 设置压缩

osgDB::writeNodeFile(*(node.get()), osgb_path, options);

osgconv a.osg a.osgb -O Compressor=zlib

不起作用的话，添上WriteImageHint=IncludeData