osgearth_city例子总结

osgearth_city例子总结

转自：http://blog.csdn.net/taor1/article/details/8242480

int main(int argc, char** argv)

{

    osg::ArgumentParser arguments(&argc,argv);

    // create the map.

    Map* map = new Map();

 

    // add a TMS imagery layer:

    TMSOptions imagery;

    imagery.url() = "http://readymap.org/readymap/tiles/1.0.0/22/";

    map->addImageLayer( new ImageLayer("ReadyMap imagery", imagery) );

 

    // create a feature source to load the building footprint shapefile.

    OGRFeatureOptions feature_opt;

    feature_opt.name() = "buildings";

    feature_opt.url() = "../data/boston_buildings_utm19.shp";

    feature_opt.buildSpatialIndex() = true;

    

    // a style for the building data:

    Style buildingStyle;

    buildingStyle.setName( "default" );

 

    ExtrusionSymbol* extrusion = buildingStyle.getOrCreate();

    extrusion->heightexpression_r() = Numericexpression_r( "3.5 * max( [story_ht_], 1 )" );

    extrusion->flatten() = true;

    extrusion->wallStyleName() = "building-wall";

    extrusion->roofStyleName() = "building-roof";

 

    // a style for the wall textures:

    Style wallStyle;

    wallStyle.setName( "building-wall" );

    SkinSymbol* wallSkin = wallStyle.getOrCreate();

    wallSkin->libraryName() = "us_resources";

    wallSkin->addTag( "building" );

    wallSkin->randomSeed() = 1;

 

    // a style for the rooftop textures:

    Style roofStyle;

    roofStyle.setName( "building-roof" );

    SkinSymbol* roofSkin = roofStyle.getOrCreate();

    roofSkin->libraryName() = "us_resources";

    roofSkin->addTag( "rooftop" );

    roofSkin->randomSeed() = 1;

    roofSkin->isTiled() = true;

 

    // assemble a stylesheet and add our styles to it:

    StyleSheet* styleSheet = new StyleSheet();

    styleSheet->addStyle( buildingStyle );

    styleSheet->addStyle( wallStyle );

    styleSheet->addStyle( roofStyle );

    

    // load a resource library that contains the building textures.

    ResourceLibrary* reslib = 

         new ResourceLibrary( "us_resources", "../data/resources/textures_us/catalog.xml" );

    styleSheet->addResourceLibrary( reslib );

 

    // set up a paging layout for incremental loading.

    FeatureDisplayLayout layout;

    layout.tileSizeFactor() = 45.0;

    layout.addLevel( FeatureLevel(0.0f, 20000.0f) );

 

    // create a model layer that will render the buildings according to our style sheet.

    FeatureGeomModelOptions fgm_opt;

    fgm_opt.featureOptions() = feature_opt;

    fgm_opt.styles() = styleSheet;

    fgm_opt.layout() = layout;

 

    map->addModelLayer( new ModelLayer( "buildings", fgm_opt ) );

 

    // initialize a viewer:

    osgViewer::Viewer viewer(arguments);

    EarthManipulator* manip = new EarthManipulator();

    viewer.setCameraManipulator( manip );

 

    // make the map scene graph:

    osg::Group* root = new osg::Group();

    viewer.setSceneData( root );

 

    MapNode* mapNode = new MapNode( map );

    root->addChild( mapNode );

    

    // Process cmdline args

    MapNodeHelper helper;

    helper.configureView( &viewer );

//在configureView中加入了

// add some stock OSG handlers:

//view->addEventHandler(new osgViewer::StatsHandler());

//view->addEventHandler(new osgViewer::WindowSizeHandler());

//view->addEventHandler(new osgViewer::ThreadingHandler());

//view->addEventHandler(new osgViewer::LODScaleHandler());

//view->addEventHandler(new osgGA::StateSetManipulator(view->getCamera()->getOrCreateStateSet()));

 

// osgEarth benefits from pre-compilation of GL objects in the pager. In newer versions of

// OSG, this activates OSG's IncrementalCompileOpeartion in order to avoid frame breaks.

//view->getDatabasePager()->setDoPreCompile( true );

 

    helper.parse(mapNode, arguments, &viewer, root, new LabelControl("City Demo"));

    //处理控制台命令

    // zoom to a good startup position

    manip->setViewpoint( Viewpoint(-71.0763, 42.34425, 0, 24.261, -21.6, 3450.0), 5.0 );

 

    viewer.getDatabasePager()->setDoPreCompile( true );

    viewer.getCamera()->addCullCallback( new AutoClipPlaneCullCallback(mapNode) );

 

    return viewer.run();

}

 

1、Map* map=new Map();//创建一个地图

   TMSOptions imagery;//图像层

   imagery.url() = "http://readymap.org/readymap/tiles/1.0.0/22/";

   map->addImageLayer(new ImageLayer("....",imagery));//加入该层

 

2、得到建筑物的矢量轮廓

   OGRFeatureOptions feature_opt;

   feature_opt.name()="buildings";

   feature_opt.url()=".....shp";//矢量文件路径

   feature_opt.buildSpatialIndex()=true;//构建空间索引，既然是索引，感觉是不是应该提速的。？？？

 

3、建筑物的风格

   Style buildingStyle;

   buildingStyle.setName("default");

   ExtrusionSymbol* extrusion=buildingStyle.getOrCreate();

   extrusion->height()=Numericexpression_r(3.5*max([story_ht_],1));//这应该是把建筑物拔高的

   extrusion->flatten()=true;//这应该是是屋顶平的

   extrusion->wallStyleName()="building_wall";//墙的风格名

   extrusion->roofStyleName()="building_roof";//屋顶的风格名

 

4、墙的纹理

   Style wallStyle;

   wallStyle.setName("building_wall");

   SkinSymbol* wallSkin=wallStyle.getOrCreate();

   wallSkin->libraryName()="us_resource";//资源库名

   wallSkin->addTag("building");//用资源库中building标签

   wallSkin->randomSeed()=1;在多个building中随机取值

 

5、房顶纹理

   // a style for the rooftop textures:

    Style roofStyle;

    roofStyle.setName( "building-roof" );

    SkinSymbol* roofSkin = roofStyle.getOrCreate();

    roofSkin->libraryName() = "us_resources";

    roofSkin->addTag( "rooftop" );

    roofSkin->randomSeed() = 1;

    roofSkin->isTiled() = true;//进行分块

 

6、组装style

     // assemble a stylesheet and add our styles to it:

    StyleSheet* styleSheet = new StyleSheet();

    styleSheet->addStyle( buildingStyle );

    styleSheet->addStyle( wallStyle );

    styleSheet->addStyle( roofStyle );

 

7、加载资源库

    ResourceLibrary* resLib=new ResourceLibrary("us_resource","../data/resources/textures_us/catalog.xml");

    

8、对页面进行分块，加快加载

   FeatureDisplayLayout layout;

   layout.tileSizeFactor()=45.0;//分成45块

   layout.addLevel(FeatureLevel(0.0,20000.0));范围是0-20000.0，所以每块大小为20000.0/45.0

 

9、现在在图像层上，加入建筑物层

   FeatureGeomModelOptions fgm_opt;

   fgm_opt.layout()=layout;

   fgm_opt.styles()=styleSheet;

   fgm_opt.featureOptions()=feature_opt;

   map->addModelLayer(new ModelLayer("building",fgm_opt));

 

10、加入场景

    // make the map scene graph:

    osg::Group* root = new osg::Group();

    viewer.setSceneData( root );

    MapNode* mapNode=new MapNode(map);

    root->addChild(mapNode);

    MapNodeHelper helper;

    helper.configureView(&viewer);

   //在configureView中加入了

// add some stock OSG handlers:

//view->addEventHandler(new osgViewer::StatsHandler());

//view->addEventHandler(new osgViewer::WindowSizeHandler());

//view->addEventHandler(new osgViewer::ThreadingHandler());

//view->addEventHandler(new osgViewer::LODScaleHandler());

//view->addEventHandler(new osgGA::StateSetManipulator(view->getCamera()->getOrCreateStateSet()));

 

// osgEarth benefits from pre-compilation of GL objects in the pager. In newer versions of

// OSG, this activates OSG's IncrementalCompileOpeartion in order to avoid frame breaks.

//view->getDatabasePager()->setDoPreCompile( true );

      helper.parse(mapNode, arguments, &viewer, root, new LabelControl("City Demo"));//处理控制台命令,在屏幕左下角加上LabelControl控件

       // zoom to a good startup position

    manip->setViewpoint( Viewpoint(-71.0763, 42.34425, 0, 24.261, -21.6, 3450.0), 5.0 );    //5秒内转到设置的视点

    viewer.getDatabasePager()->setDoPreCompile( true );

    viewer.getCamera()->addCullCallback( new AutoClipPlaneCullCallback(mapNode) );