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) );