OSG学习：使用OSG中预定义的几何体

常用的内嵌几何体包括：

osg::Box                    //正方体

osg::Capsule                //太空舱

osg::Cone                   //椎体

osg::Cylinder               //柱体

osg::HeightField            //高度图

osg::InfinitePlane          //无限平面

osg::Sphere                 //球体

osg::TriangleMesh           //三角片

以下是代码示例：

/**********************************************************

*Write by FlySky

*[email protected]  http://www.OsgChina.org

**********************************************************/

#include <osgViewer/Viewer>

#include <osg/Node>

#include <osg/Geode>

#include <osg/Group>

#include <osg/ShapeDrawable>

#include <osgDB/ReadFile>

#include <osgDB/WriteFile>

#include <osgUtil/Optimizer>

//绘制多个预定义的几何体

osg::ref_ptr<osg::Geode> createShape()

{

    //创建一个叶节点

    osg::ref_ptr<osg::Geode> geode = new osg::Geode();

    //设置半径和高度

    float radius = 0.8f;

    float height = 1.0f;

    //创建精细度对象，精细度越高，细分就越多

    osg::ref_ptr<osg::TessellationHints> hints = new osg::TessellationHints;

    //设置精细度为0.5f

    hints->setDetailRatio(0.5f);

    //添加一个球体，第一个参数是预定义几何体对象，第二个是精细度，默认为0

    geode->addDrawable(new osg::ShapeDrawable(new osg::Sphere(osg::Vec3(0.0f,0.0f,0.0f),radius),hints.get()));

    //添加一个正方体

    geode->addDrawable(new osg::ShapeDrawable(new osg::Box(osg::Vec3(2.0f,0.0f,0.0f),2*radius),hints.get()));

    //添加一个圆锥

    geode->addDrawable(new osg::ShapeDrawable(new osg::Cone(osg::Vec3(4.0f,0.0f,0.0f),radius,height),hints.get()));

    //添加一个圆柱体

    geode->addDrawable(new osg::ShapeDrawable(new osg::Cylinder(osg::Vec3(6.0f,0.0f,0.0f),radius,height),hints.get()));

    //添加一个太空舱

    geode->addDrawable(new osg::ShapeDrawable(new osg::Capsule(osg::Vec3(8.0f,0.0f,0.0f),radius,height),hints.get()));

    return geode.get() ;

}

int main()

{

    //创建Viewer对象，场景浏览器

    osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer();

    osg::ref_ptr<osg::Group> root = new osg::Group();

    //添加到场景

    root->addChild(createShape());

    //优化场景数据

    osgUtil::Optimizer optimizer ;

    optimizer.optimize(root.get()) ;

    viewer->setSceneData(root.get());

    viewer->realize();

    viewer->run();

    return 0 ;

}

结果图：