环境及准备
系统：macOS 10.13
Xcode:10.1
Cmake:3.11(https://cmake.org/download/)
OSG:3.6.1(http://www.openscenegraph.org/index.php/download-section/stable-releases)
OSGEarth:2.10(https://github.com/gwaldron/osgearth/tree/2.10)
3rdParty:https://pan.baidu.com/s/1Z9Hx912VOZgo4h8cgSiCRQ 密码:4tsk
步骤
step1
新建一个文档，将3rdParty、OSG、OSGEarth文件都放入
打开Cmake，点击Tools--How to install For Command Line Use
开始编译OSG，这里说一下，OSG的文档写得很友好，打开里面的readme.md按照他的CMAKE Command就可以，如果想要用CmakeGUI一条一条设置也可以，但是最好设置一条就Configure一下，解决掉红色提醒后再Generate。
这里仅介绍使用终端以命令行方式去Build:
cd OpenSceneGraph3.6.1 path
export THIRDPARTY_PATH=/path/to/my/3rdParty
cmake ./ -G Xcode -DOSG_BUILD_PLATFORM_IPHONE:BOOL=ON \
-DIPHONE_SDKVER="12.1" \
-DIPHONE_VERSION_MIN="10.0" \
-DOPENGL_PROFILE:STRING=GLES3 \
-DBUILD_OSG_APPLICATIONS:BOOL=OFF \
-DBUILD_OSG_EXAMPLES:BOOL=ON \
-DOSG_WINDOWING_SYSTEM:STRING=IOS \
-DOSG_DEFAULT_IMAGE_PLUGIN_FOR_OSX="imageio" \
-DDYNAMIC_OPENSCENEGRAPH:BOOL=OFF \
-DDYNAMIC_OPENTHREADS:BOOL=OFF \
-DOSG_CPP_EXCEPTIONS_AVAILABLE:BOOL=ON \
-DCURL_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/curl-ios-device/include" \
-DCURL_LIBRARY:PATH="$THIRDPARTY_PATH/curl-ios-device/lib/libcurl.a" \
-DFREETYPE_INCLUDE_DIR_freetype2:PATH="$THIRDPARTY_PATH/freetype-ios-universal/include/freetype" \
-DFREETYPE_INCLUDE_DIR_ft2build:PATH="$THIRDPARTY_PATH/freetype-ios-universal/include" \
-DFREETYPE_LIBRARY:PATH="$THIRDPARTY_PATH/freetype-ios-universal/lib/libFreetype2.a" \
-DTIFF_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/tiff-ios-device/include" \
-DTIFF_LIBRARY:PATH="$THIRDPARTY_PATH/tiff-ios-device/lib/libtiff.a" \
-DGDAL_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/gdal-ios-device/include" \
-DGDAL_LIBRARY:PATH="$THIRDPARTY_PATH/gdal-ios-device/lib/libgdal.a"
cd 进你的OpenSceneGraph3.6.1文件夹，THIRDPARTY_PATH的路径就是你的3rdparty文件路径，IPHONE_SDKVER和IPHONE_VERSION_MIN可以按照你的Xcdoe版本自己设置，显示完成后打开OpenSceneGraph.xcodeproj，添加New Scheme，选择All Build，使用Release Build。如果需要跑OSG的DEMO，选择Target--example_osgViewerIPhone--Build Settings--Other Linker Flags--Release 删除oepngGl 以及上面的-framework，Build。
如果你用的是Xcode10以上，可能会在编译Pthread.cpp的时候报错，可以将错误的地方注释掉不影响编译,当然你也可以选择较低的Xcode版本，这样比较稳定
Step2
cd 进入osgearth文件夹,在终端输入以下命令：
export THIRDPARTY_PATH=/Users/zhcode/osgearthBuild/3rdParty
cmake ./ -G Xcode -DOSGEARTH_BUILD_PLATFORM_IPHONE:BOOL=ON \
-DIPHONE_SDKVER="12.1" \
-DIPHONE_VERSION_MIN="10.0" \
-DOSG_DIR:PATH="/Users/zhcode/osgearthBuild/OpenSceneGraph3.6.1" \
-DCURL_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/curl-ios-device/include" \
-DCURL_LIBRARY:PATH="$THIRDPARTY_PATH/curl-ios-device/lib/libcurl.a" \
-DGDAL_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/gdal-ios-device/include" \
-DGDAL_LIBRARY:PATH="$THIRDPARTY_PATH/gdal-ios-device/lib/libgdal.a" \
-DGEOS_INCLUDE_DIR:PATH="$THIRDPARTY_PATH/geos-ios-device/include/source/headers" \
-DGEOS_LIBRARY:PATH="$THIRDPARTY_PATH/geos-ios-device/lib/libGEOS_3.2.a" \
-DPROJ_LIBRARY:PATH="$THIRDPARTY_PATH/proj4-ios-device/lib/libproj.a" \
-DFREETYPE_LIBRARY:PATH="$THIRDPARTY_PATH/freetype-ios-universal/lib/libFreetype2.a" \
-DOSGEARTH_BUILD_APPLICATION_BUNDLES:BOOL=ON \
-DBUILD_OSGEARTH_EXAMPLES:BOOL=ON \
-DDYNAMIC_OSGEARTH:BOOL=OFF
同样，将文件位置改为你自己的位置即可,打开project文件，选择文件----projectSetting---buildSystem 选择legacy build system，将build模式该为release,选择example目标build,静待完成。
