osg节点拾取 & 点击切换高亮

#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgGA/GUIEventHandler>
#include <osgFX/Outline>

class nodePick :public osgGA::GUIEventHandler
{
virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
osgViewer::Viewer *viewer = dynamic_cast<osgViewer::Viewer*> (&aa);
switch (ea.getEventType())
{
case osgGA::GUIEventAdapter::PUSH:
{
 osgUtil::LineSegmentIntersector::Intersections intersections;
 osg::ref_ptr<osg::Node> node = new osg::Node;
 if (viewer->computeIntersections(ea.getX(), ea.getY(), intersections))
 {
 //得到选择的节点
 osgUtil::LineSegmentIntersector::Intersection intersection = *intersections.begin();
 osg::NodePath& nodePath = intersection.nodePath;
 node = nodePath.back();


 //点击节点切换高亮
 osg::ref_ptr<osg::Group> parent = new osg::Group;
 parent = dynamic_cast<osg::Group*> (nodePath[nodePath.size() - 2]);//当前选择节点的父节点
 osgFX::Outline *ot = dynamic_cast<osgFX::Outline*>(parent.get());
 if (!ot) //若ot不存在（未高亮） (node->parent)=>(node->outline->parent)
 {