[原][osgEarth]在osgearth中添加相机路径动画

在osg中添加相机动画路径请参考：http://www.cnblogs.com/lyggqm/p/8075277.html

这里的代码是在osgearth中添加相机动画路径漫游器：

#include <osg/Image>
#include <osgGA/StateSetManipulator>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgEarth/Map>
#include <osgEarth/MapNode>
#include <osgEarth/Registry>
#include <osgEarthSymbology/Geometry>
#include <osgEarthSymbology/GeometryRasterizer>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/AutoClipPlaneHandler>
#include <osgEarth/ImageToHeightFieldConverter>
#include <osgEarth/ImageUtils>
#include <osgEarth/FileUtils>
#include <osgEarth/Registry>
#include <osgEarth/MapFrame>
#include <osgDB/FileUtils>
#include <osgDB/FileNameUtils>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>

#include <osgEarthUtil/ExampleResources>
#include <math.h>

#include <osgGA/NodeTrackerManipulator>
#include <osgGA/AnimationPathManipulator>
#include <osgGA/KeySwitchMatrixManipulator>
using namespace osgEarth;
using namespace osgEarth::Util;
using namespace osgEarth::Symbology;


int main(int argc, char** argv)
{
    //正常的.earth文件加载
    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer(arguments);
    MapNode* s_mapNode = 0L;
    osg::Node* earthFile = MapNodeHelper().load(arguments, &viewer);
    if (earthFile)
        s_mapNode = MapNode::get(earthFile);
    if (!s_mapNode)
    {
        OE_WARN << "Unable to load earth file." << std::endl;
        return -1;
    }
    osg::Group* root = new osg::Group();
    root->addChild(earthFile);
    viewer.setSceneData(root);

    //模型漫游器
    osgGA::NodeTrackerManipulator* nodeTrack = new osgGA::NodeTrackerManipulator();
    nodeTrack->setTrackNode(root);


    /*************************************动画漫游器**下*********************************/
    GeoPoint gPoint1(s_mapNode->getMap()->getSRS(), 32, 118, 400);
    osg::Matrix gMatrix1;
    gPoint1.createLocalToWorld(gMatrix1);//获取当前地球上的正确姿态
    //由于相机，自身向下看，所以在当前姿态基础上抬起60度，注意是前乘！
    gMatrix1.preMultRotate(osg::Quat(osg::DegreesToRadians(60.0), osg::X_AXIS));
    osg::Quat q1;    gMatrix1.get(q1);//获取当前矩阵姿态
    osg::Vec3d vPos1 = gMatrix1.getTrans();//获取当前矩阵位置

    GeoPoint gPoint2(s_mapNode->getMap()->getSRS(), 32.01, 118.01, 400);
    osg::Matrix gMatrix2;
    gPoint2.createLocalToWorld(gMatrix2);
    gMatrix2.preMultRotate(osg::Quat(osg::DegreesToRadians(60.0), osg::X_AXIS));
    osg::Quat q2;    
    gMatrix2.get(q2);
    osg::Vec3d vPos2 = gMatrix2.getTrans();

    GeoPoint gPoint3(s_mapNode->getMap()->getSRS(), 32.02, 118.02, 400);
    osg::Matrix gMatrix3;
    gPoint3.createLocalToWorld(gMatrix3);
    osg::Quat q3;
    gMatrix3.get(q3);
    osg::Vec3d vPos3 = gMatrix3.getTrans();
    //获取相机之后再顺旋转,其实是错误的姿态
    osg::Quat qbuf(osg::DegreesToRadians(60.0), osg::X_AXIS);
    q3    *= qbuf;

    //使用动画漫游器
    osgGA::AnimationPathManipulator *animationPathMp = new osgGA::AnimationPathManipulator();
    //给动画漫游器添加关键帧
    osg::AnimationPath* _animationPath = new osg::AnimationPath;
    _animationPath->insert(0.0, osg::AnimationPath::ControlPoint(vPos1, q1));//姿态正确
    _animationPath->insert(3.0, osg::AnimationPath::ControlPoint(vPos2, q2));//姿态正确
    _animationPath->insert(6.0, osg::AnimationPath::ControlPoint(vPos3, q3));//姿态错误！
    _animationPath->setLoopMode(osg::AnimationPath::SWING);//设置路径是回摆的
    animationPathMp->setAnimationPath(_animationPath);
    /*************************************动画漫游器**上*********************************/


    //这里添加三个漫游器，使用一个控制漫游器选择，按键盘‘3’就切换到路径动画漫游器了
    osgGA::KeySwitchMatrixManipulator* keyPtr = new osgGA::KeySwitchMatrixManipulator();
    keyPtr->addMatrixManipulator('1', "earthMan", new EarthManipulator());
    keyPtr->addMatrixManipulator('2', "trakerMan", nodeTrack);
    keyPtr->addMatrixManipulator('3', "animationPathMan", animationPathMp);
    viewer.setCameraManipulator(keyPtr);

    return viewer.run();
}

有几点要注意：

1.这个dome在vs运行时，需要添加外部earth文件参数：

红色部分填写适合当前earth版本的‘.earth’文件

2.添加的其实是一个漫游器，基于路径点的相机漫游器

3.添加的路径点有两个姿态的变幻，展示一个正确相机姿态调整方式，一个错误的：

 正确的：

错误的：