osg节点拾取

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

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();

 //点击节点透明
 node->setNodeMask(0);
 }
}
default:
return false;
}
}