osg節點拾取

使用Scribe特效實現白色輪廓，此類在osgFx模塊裏面。

所有場景中的節點全部添加Scribe特效。

通過繼承GUIEventHandler來自定義鼠標對應動作時，需要進行何種操作。

在事件處理器類中，實現左鍵時判斷鼠標點擊位置是否和節點相交，然後隱藏特效；

右鍵時恢復特效。

判斷是否相交，使用computeIntersections來計算，這是osgViewer的函數。

完整代碼：

#include <osg/Group>
#include <osgViewer/Viewer>
#include <osgGA/GUIEventHandler>
#include <osg/ShapeDrawable>
#include <osgFX/Scribe>
#include <osg/Node>
#include <osgDB/ReadFile>

#pragma comment(lib,"osgd.lib")
#pragma comment(lib,"osgviewerd.lib")
#pragma comment(lib,"osgFXd.lib")
#pragma comment(lib,"osggad.lib")
#pragma comment(lib,"osgUtild.lib")
#pragma comment(lib,"osgdbd.lib")

class CEventHandler :public osgGA::GUIEventHandler
{
public:
	CEventHandler(osgViewer::Viewer *viewer) :m_pThis(viewer){};

	virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& ga)
	{
		switch (ea.getEventType())
		{
		case osgGA::GUIEventAdapter::PUSH:
			Pick(ea.getX(), ea.getY(), ea.getButton());
			break;
		default:
			break;
		}
		return true;
	}

protected:
	void Pick(float x, float y,int button)
	{
		osgUtil::LineSegmentIntersector::Intersections datas;
		if (button == 1 && m_pThis->computeIntersections(x, y, datas))//左鍵隱藏
		{
			for (auto it = datas.begin(); it != datas.end();it++)
			{
				osg::NodePath nodePath = it->nodePath;
				for (int i = 0; i < nodePath.size(); i++)
				{
					osgFX::Scribe *sc = dynamic_cast<osgFX::Scribe*>(nodePath[i]);
					if (sc)
					{
						auto it = std::find(m_scribeList.begin(), m_scribeList.end(), sc);
						if (it != m_scribeList.end())
							continue;
						sc->setNodeMask(0);
						m_scribeList.push_back(sc);
					}
				}
			}
		}
		else if (button == 4)//右鍵顯示
		{
			for (auto it = m_scribeList.begin(); it != m_scribeList.end();it++)
				it->get()->setNodeMask(1);
			m_scribeList.clear();
		}
	}

	osgViewer::Viewer* m_pThis;
	osg::NodeList m_scribeList;
};

int main(int argc, char **argv)
{
	osgViewer::Viewer viewer;

	osg::ref_ptr<osg::Group> group = new osg::Group;
	osg::ref_ptr<osg::ShapeDrawable> coneDraw = new osg::ShapeDrawable(new osg::Cone(osg::Vec3(10.f, 0.f, 0.f), 2.f, 40.f));
	osg::ref_ptr<osg::ShapeDrawable> sphereDraw = new osg::ShapeDrawable(new osg::Sphere(osg::Vec3(-10.f, 0.f, 0.f), 2.f));

	osg::ref_ptr<osgFX::Scribe> scribe1 = new osgFX::Scribe;
	osg::ref_ptr<osg::Node> node1 = osgDB::readNodeFile("cessna.osgt");
	//scribe1->setNodeMask(0);
	scribe1->addChild(node1);

	osg::ref_ptr<osgFX::Scribe> scribe2 = new osgFX::Scribe;
	osg::ref_ptr<osg::Node> node2 = osgDB::readNodeFile("cow.osgt");
	//scribe2->setNodeMask(0);
	scribe2->addChild(node2);

	group->addChild(node1);
	group->addChild(node2);
	group->addChild(scribe1);
	group->addChild(scribe2);

	viewer.setSceneData(group);
	viewer.addEventHandler(new CEventHandler(&viewer));
	viewer.realize();
	return viewer.run();
}

本文地址：http://blog.csdn.net/u011417605/article/details/71089309

源碼下載：http://download.csdn.net/detail/u011417605/9831401