OSG利用DrawCallback实现模型重绘(Qt5.14.2+osgE3.6.5+win10)-No25-DrawCallb

#include <QApplication> #include <osg/Node> #include <osg/Group> #include <osg/Geode> #include <osg/Geometry> #include <osg/Texture2D> #include <osg/StateSet> #include <osg/PositionAttitudeTransform> #include <osgViewer/Viewer> #include <osgDB/ReadFile> #include <osgParticle/PrecipitationEffect> // 雨雪效果 #include <osg/MatrixTransform> // 粒子效果 #include <osgParticle/PrecipitationEffect> #include <osgParticle/Particle> #include <osgParticle/LinearInterpolator> #include <osgParticle/ParticleSystem> #include <osgParticle/RandomRateCounter> #include <osgParticle/PointPlacer> #include <osgParticle/RadialShooter> #include <osgParticle/ModularEmitter> #include <osgParticle/ParticleSystemUpdater> #include <osgParticle/ModularProgram> #include <osgUtil/Optimizer> #include <osgUtil/Simplifier> #include <osgParticle/FireEffect> // 雾 #include <osg/Fog> #include <osgDB/ReadFile> #include <osgViewer/Viewer> #include <osg/StateSet> #include <osg/StateAttribute> #include <osgViewer/ViewerEventHandlers> #include <osgWidget/ViewerEventHandlers> // #include <QDebug> class MyDrawCallback : public osg::Drawable::DrawCallback { public: void drawImplementation(osg::RenderInfo &renderInfo, const osg::Drawable *drawable) const { qDebug() <<"draw call back - pre drawImplementation"<<drawable ; drawable->drawImplementation(renderInfo); qDebug() <<"draw call back - post drawImplementation"<<drawable ; static double dColor = 0;//颜色 glColor3f(dColor, 0, 0); glBegin(GL_TRIANGLES);//在OSG中画一个opengl三角形 glVertex3f(0.0, 0.0, -2.0); glVertex3f(0.2, 0.0, -2.0); glVertex3f(0.0, 0.4, -2.0); glEnd(); dColor += 0.01;//颜色渐变 if (dColor > 1.0) { dColor = 0.0; } } }; int main(int argc, char *argv[]) { osgViewer::Viewer viewer; osg::ref_ptr<osg::Group> root=new osg::Group(); osg::ref_ptr<osg::Node> osgcool=osgDB::readNodeFile("D:\\Gitee\\data\\cow.osg"); osg::Group* ttt=osgcool->asGroup(); osg::Geometry* geom = ttt->getChild(0)->asGeode()->getChild(0)->asGeometry(); geom->setUseDisplayList(false); geom->setDrawCallback(new MyDrawCallback()); osg::ref_ptr<osg::MatrixTransform> trans=new osg::MatrixTransform(); // osg::Matrix::scale(0.5,0.5,0.5)表示缩放的比例，也就是原来物体的一般大小 // *osg::Matrix::translate(0,-10,0)表示平移正前 trans->setMatrix(osg::Matrix::scale(0.5,0.5,0.5)*osg::Matrix::translate(0,-10,0)); trans->addChild(osgcool.get()); root->addChild(osgcool.get()); root->addChild(trans.get()); viewer.setUpViewInWindow(50,50,500,400); viewer.setSceneData(root.get()); viewer.realize(); viewer.run(); }