//2017. 8 .29
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>#include <osg/Node>
#include <osg/Geode>
#include <osg/Group>
#include <osg/Math>
#include <osg/AnimationPath>
#include <osg/MatrixTransform>
#include <osg/PositionAttitudeTransform>#include <osgDB/ReadFile>
#include <osgDB/WriteFile>#include <osgUtil/Optimizer>//路径动画控制事件
class AnimationEventHandler : public osgGA::GUIEventHandler
{
public:AnimationEventHandler(osgViewer::Viewer &vr):viewer(vr){}//事件处理virtual bool handle(const osgGA::GUIEventAdapter &ea, osgGA::GUIActionAdapter &){//创建动画更新回调对象osg::ref_ptr<osg::AnimationPathCallback> animationPathCallback = new osg::AnimationPathCallback();osg::ref_ptr<osg::Group> group = dynamic_cast<osg::Group*>(viewer.getSceneData());//取得节点的动画属性animationPathCallback = dynamic_cast<osg::AnimationPathCallback*>(group->getChild(0)->getUpdateCallback());switch(ea.getEventType()){case (osgGA::GUIEventAdapter::KEYDOWN):{if (ea.getKey() == 'p'){//暂停animationPathCallback->setPause(true);return true;}if (ea.getKey() == 'k'){//开始animationPathCallback->setPause(false);return true;}if (ea.getKey() == 'r'){//重新开始animationPathCallback->reset();return true;}break;}default:break;}return false;}public:osgViewer::Viewer &viewer;
};//创建路径
osg::ref_ptr<osg::AnimationPath> creatAnimationPath(osg::Vec3 ¢er, float radius, float looptime)
{//创建一个Path对象osg::ref_ptr<osg::AnimationPath> animationPath = new osg::AnimationPath();//设置动画模式为循环（LOOP）//LOOP:循环  SWING:单摆   NO_LOOPING:不循环animationPath->setLoopMode(osg::AnimationPath::LOOP);//关键点数int numPoint = 60;//每次偏移角度float yaw = 0.0f;float yaw_delta = 2.0 * osg::PI / ((float)(numPoint - 1.0f));//倾斜角度float roll = osg::inDegrees(45.0f);//时间偏移float time = 0.0f;float time_delta = looptime / ((float)(numPoint));for (int i = 0; i < numPoint; i++){//关键点位置osg::Vec3 position(center + osg::Vec3(sinf(yaw) * radius, cosf(yaw) * radius,0.0f));//关键点角度osg::Quat rotation(osg::Quat(roll, osg::Vec3(0.0, 1.0, 0.0)) * osg::Quat( -(yaw + osg::inDegrees(90.f)), osg::Vec3(0.0, 0.0, 1.0)));//插入Path，把关键点与时间压入形成PathanimationPath->insert(time, osg::AnimationPath::ControlPoint(position, rotation));yaw += yaw_delta;time += time_delta;}//返回Pathreturn animationPath.get();
}int main()
{osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer();osg::ref_ptr<osg::Group> root = new osg::Group();//读入飞机模型osg::ref_ptr<osg::Node> cessna = osgDB::readNodeFile("cessna.osg");//读入地形模型osg::ref_ptr<osg::Node> node = osgDB::readNodeFile("lz.osg");//得到包围盒，来确定动画旋转中心const osg::BoundingSphere &bs = cessna->getBound();osg::Vec3 position = bs.center() + osg::Vec3(0.0f, 0.0f, 200.f);//缩放比例，如果比例不当，模型会看不见float size = 100.0f / bs.radius() * 0.3f;//创建路径osg::ref_ptr<osg::AnimationPath> animationPath = new osg::AnimationPath();animationPath = creatAnimationPath(position, 200.0f, 10.0f);osg::ref_ptr<osg::MatrixTransform> mt = new osg::MatrixTransform();//OSG确保只有STATIC数据可以进行图形渲染mt->setMatrix(osg::Matrix::translate( -bs.center()) * osg::Matrix::scale(size, size, size) * osg::Matrix::rotate(osg::inDegrees(-180.0f), 0.0f,0.0f,1.0f));mt->addChild(cessna.get());osg::ref_ptr<osg::PositionAttitudeTransform> pat = new osg::PositionAttitudeTransform();//设置更新回调pat->setUpdateCallback(new osg::AnimationPathCallback(animationPath.get(), 0.0f, 1.0f));pat->addChild(mt.get());root->addChild(pat.get());root->addChild(node.get());//优化场景数据osgUtil::Optimizer optimizer;optimizer.optimize(root.get());viewer->setSceneData(root.get());//添加路径动画viewer->addEventHandler(new AnimationEventHandler(*(viewer.get())));viewer->realize();viewer->run();return 0;}