osg简单回调callback

#include <Windows.h>
#include <osgViewer/Viewer>
#include <osg/Math> 
#include <osgDB/ReadFile> 
#include <osg/NodeCallback> 
#include <osg/MatrixTransform> 
//从osg::NodeCallBack继承一个新类，实现simpleCallBack的回调
class simpleCallBack:public osg::NodeCallback
{
public:
    simpleCallBack():_angle(0)
    {

    }

    virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
    {
        //创建矩阵转换节点
        osg::ref_ptr<osg::MatrixTransform> mt=dynamic_cast<osg::MatrixTransform*>(node);
        //创建矩阵
        osg::Matrix mx;
        //绕着Z轴旋转
        mx.makeRotate(_angle,osg::Vec3(0.0,0.0,1.0));
        //设置矩阵
        mt->setMatrix(mx);

        _angle+=0.01;

        //继续遍历
        traverse(node,nv);

    }

public:
    //旋转角度
    double _angle;
};

int main()
{
    osg::ref_ptr<osgViewer::Viewer> viewer=new osgViewer::Viewer;
    osg::ref_ptr<osg::Group> root=new osg::Group;

    //读取模型
    osg::ref_ptr<osg::Node> node=osgDB::readNodeFile("cow.osg");

    //创建矩阵变换节点
    osg::ref_ptr<osg::MatrixTransform> mt=new osg::MatrixTransform;
    mt->addChild(node.get());

    //设置更新回调函数
    mt->setUpdateCallback(new simpleCallBack());

    root->addChild(mt.get());
    viewer->setSceneData(root.get());
    viewer->realize();
    viewer->run();
    return 0;
}