osg动画

#include <osgViewer/Viewer>
#include <osg/MatrixTransform>
#include <osgDB/ReadFile>
#include <osg/Callback>
#include <osgAnimation/Animation>

class RotateCallback : public osg::NodeCallback
{
public:
	RotateCallback(osgAnimation::Animation *dls)
	{
		_startTick = osg::Timer::instance()->tick();
		_animation = dls;
	}

	virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
	{
		osg::MatrixTransform *mt = dynamic_cast<osg::MatrixTransform*>(node);
		if (mt)
		{
			double currentTick = osg::Timer::instance()->tick();
			double elaspedTime = osg::Timer::instance()->delta_s(_startTick, currentTick);

			_animation->resetTargets();
			_animation->setPlayMode(osgAnimation::Animation::LOOP);
			_animation->update(elaspedTime);
			_animation->setWeight(1.0);

			osgAnimation::ChannelList cls = _animation->getChannels();
			double currentRot = dynamic_cast<osgAnimation::DoubleTarget*>(cls.at(0)->getTarget())->getValue();

			osg::Quat rotQuat(currentRot, osg::Z_AXIS);
			osg::Matrix rotMatrix(rotQuat);
			mt->setMatrix(rotMatrix);
		}

		traverse(node, nv);
	}
protected:
	osgAnimation::Animation*                 _animation;
	double                                   _startTick;
};

int main()
{
	osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;
	osg::ref_ptr<osg::Node> cowNode = osgDB::readNodeFile("cow.osg");
	osg::ref_ptr<osg::MatrixTransform> root = new osg::MatrixTransform;
	root->addChild(cowNode);

	osgAnimation::DoubleKeyframe keyframe1(0.0, 0.0);
	osgAnimation::DoubleKeyframe keyframe2(10.0, osg::PI * 2);

	osg::ref_ptr<osgAnimation::DoubleKeyframeContainer> keyframeContainer = new osgAnimation::DoubleKeyframeContainer();
	keyframeContainer->push_back(keyframe1);
	keyframeContainer->push_back(keyframe2);
	osg::ref_ptr<osgAnimation::DoubleLinearSampler> sampler = new osgAnimation::DoubleLinearSampler();
	sampler->setKeyframeContainer(keyframeContainer.get());
	osg::ref_ptr<osgAnimation::DoubleLinearChannel> channel = new osgAnimation::DoubleLinearChannel();
	channel->setSampler(sampler.get());

	osg::ref_ptr<osgAnimation::Animation> animation = new osgAnimation::Animation();
	animation->addChannel(channel.get());

	root->addUpdateCallback(new RotateCallback(animation.get()));

	viewer->setUpViewInWindow(200, 200, 800, 600);
	viewer->setSceneData(root);
	return viewer->run();
}