用OpenSceneGraph实现的NeHe OpenGL教程 - 第二十六课

• 简介

这节课主要介绍了如何使用OpenGL中的模板缓冲区和裁剪平面来产生镜子反射的效果，关于模板缓冲区的内容可以参考另一篇文章OpenGL模板缓冲区---Stencil Buffer

• 实现

首先我们需要在模板缓冲区中将地面(类似镜子)绘制出来，同时并不会在颜色缓冲区中绘制出镜面。通过设置颜色掩码glColorMask可以做到这一点

	//创建模板缓冲区中的镜面(不可见)
	//深度测试关闭意味着深度测试总是通过
	osg::Geode *stencilFloorGeode = createFloor();
	osg::Stencil *floorStencil = new osg::Stencil;
	floorStencil->setFunction(osg::Stencil::ALWAYS, 1, 1);
	floorStencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::REPLACE);
	osg::ColorMask *colorMask1 = new osg::ColorMask(0, 0, 0, 0);
	stencilFloorGeode->getOrCreateStateSet()->setMode(GL_DEPTH_TEST, false);
	stencilFloorGeode->getOrCreateStateSet()->setAttribute(colorMask1, osg::StateAttribute::ON);
	stencilFloorGeode->getOrCreateStateSet()->setAttributeAndModes(floorStencil);
	stencilFloorGeode->getOrCreateStateSet()->setMode(GL_LIGHTING, false);

此时在模板缓冲区中存在这一个地面(全部为1，其他模板缓冲区的部分都是0)，这时候我们在绘制球体在镜面中的镜像，我们让所有是1的地方进行绘制，这样绘制的球体只有在镜面的地方才能绘制出来，其他地方都无法绘制。

	osg::Group *reflectionBall = createSphere();
	
	osg::Stencil *stencilBall  = new osg::Stencil;
	stencilBall->setFunction(osg::Stencil::EQUAL, 1, 1);
	stencilBall->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::KEEP);

	osg::ClipPlane *clipPlane = new osg::ClipPlane(0, 0.0, -1.0, 0.0, 0.0);

	reflectionBall->getOrCreateStateSet()->setAttributeAndModes(stencilBall, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
	reflectionBall->getOrCreateStateSet()->setAttributeAndModes(clipPlane);

接下来在颜色缓冲区(可见的屏幕上)绘制真实的地面(镜子)

	osg::Geode *colorBufferFloor  = createFloor();
	osg::BlendFunc *blendFunc = new osg::BlendFunc(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::ONE_MINUS_SRC_ALPHA);
	osg::Geometry *floorGeometry = colorBufferFloor->getDrawable(0)->asGeometry();
	if (floorGeometry)
	{
		osg::Vec4Array *colorArray = new osg::Vec4Array;
		colorArray->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 0.8f));
		floorGeometry->setColorArray(colorArray, osg::Array::BIND_OVERALL);
		floorGeometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
		floorGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
	}

最后我们绘制出真实的球体：

	osg::Group *realBall = createSphere();
	transMT->addChild(rotateX);
	rotateX->addChild(rotateY);
	rotateY->addChild(realBall);

将所有绘制好的部分添加到根节点下面：

	//所有部分添加到场景节点
	root->addChild(tiltMT);
	tiltMT->addChild(stencilFloorGeode);
	tiltMT->addChild(reflectScaleMT);
	tiltMT->addChild(colorBufferFloor);
	tiltMT->addChild(transMT);

在我们操作真实球体的时候，镜像的球体实际上也在跟着上下运动，通过反转Y轴实现了这样的效果：

	osg::MatrixTransform *reflectScaleMT = new osg::MatrixTransform;
	reflectScaleMT->setMatrix(osg::Matrix::scale(1.0, -1.0, 1.0));

与键盘交互部分的代码与第二十五课中一样

编译运行程序：

附：本课源码（源码中可能存在着错误和不足，仅供参考）

/************************************************************************\
 * osgNeHe - Copyright (C) 2013-2014 Frank He
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*	A HUGE thanks to NeHe for the OpenGL tutorials< http://nehe.gamedev.net >
*
*  If you've found this code useful, Please let me know.
*  My E-mail: < [email protected] >
*  My Blog: < http://blog.csdn.net/csxiaoshui >
*
\************************************************************************/


#include "../osgNeHe.h"

#include <QtCore/QTimer>
#include <QtGui/QApplication>
#include <QtGui/QVBoxLayout>

#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgQt/GraphicsWindowQt>

#include <osg/MatrixTransform>
#include <osg/ShapeDrawable>

#include <osg/TexGen>
#include <osg/BlendFunc>
#include <osg/Texture2D>

#include <osg/ColorMask>
#include <osg/Stencil>
#include <osg/ClipPlane>

//////////////////////////////////////////////////////////////////////////
static GLfloat LightAmb[] = {0.7f, 0.7f, 0.7f, 1.0f};
static GLfloat LightDif[] = {1.0f, 1.0f, 1.0f, 1.0f};
static GLfloat LightPos[] = {4.0f, 4.0f, 6.0f, 1.0f};


GLfloat		xrot		=  0.0f;
GLfloat		yrot		=  0.0f;
GLfloat		xrotspeed	=  0.0f;
GLfloat		yrotspeed	=  0.0f;
GLfloat		zoom		= -7.0f;	
GLfloat		height		=  2.0f;

osg::MatrixTransform *g_ZoomMT = NULL;

osg::MatrixTransform *g_ReflectTrans = NULL;
osg::MatrixTransform *g_ReflectRotX = NULL;
osg::MatrixTransform *g_ReflectRotY = NULL;

osg::MatrixTransform *g_Trans = NULL;
osg::MatrixTransform *g_RotX = NULL;
osg::MatrixTransform *g_RotY = NULL;


osg::Group*	createSphere()
{
	osg::Group *sphereGroup = new osg::Group;
	osg::Geode *sphereGeode1 = new osg::Geode;
	osg::Geode *sphereGeode2 = new osg::Geode;
	
	osg::ShapeDrawable *shapeDrawable1 = new osg::ShapeDrawable;
	shapeDrawable1->setShape(new osg::Sphere(osg::Vec3(0,0,0), 0.5f));
	shapeDrawable1->setColor(osg::Vec4(1.0, 1.0, 1.0, 1.0));
	osg::Texture2D *texture1 = new osg::Texture2D;
	texture1->setImage(osgDB::readImageFile("Data/Ball.bmp"));
	texture1->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
	texture1->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
	shapeDrawable1->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture1);
	sphereGeode1->addDrawable(shapeDrawable1);
	
	osg::ShapeDrawable *shapeDrawable2 = new osg::ShapeDrawable;
	shapeDrawable2->setShape(new osg::Sphere(osg::Vec3(0,0,0), 0.5f));
	shapeDrawable2->setColor(osg::Vec4(1.0f, 1.0f, 1.0f, 0.4f));
	osg::Texture2D *texture2 = new osg::Texture2D;
	texture2->setImage(osgDB::readImageFile("Data/EnvRoll.bmp"));
	texture2->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
	texture2->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
	shapeDrawable2->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture2);
	osg::BlendFunc *blendFunc = new osg::BlendFunc(GL_SRC_ALPHA, GL_ONE);
	shapeDrawable2->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
	osg::TexGen *texGen = new osg::TexGen;
	texGen->setMode(osg::TexGen::SPHERE_MAP);
	shapeDrawable2->getOrCreateStateSet()->setTextureAttributeAndModes(0, texGen);
	sphereGeode2->addDrawable(shapeDrawable2);
	
	sphereGroup->addChild(sphereGeode1);
	sphereGroup->addChild(sphereGeode2);

	return sphereGroup;
}


osg::Geode*	createFloor()
{
	osg::Geode *geode1 = new osg::Geode;
	osg::Geometry *geometry1 = new osg::Geometry;

	osg::Vec3Array *vertexArray1 = new osg::Vec3Array;
	vertexArray1->push_back(osg::Vec3(-2.0, 0.0, 2.0));
	vertexArray1->push_back(osg::Vec3(-2.0, 0.0,-2.0));
	vertexArray1->push_back(osg::Vec3(2.0, 0.0,-2.0));
	vertexArray1->push_back(osg::Vec3(2.0, 0.0, 2.0));
	geometry1->setVertexArray(vertexArray1);
	osg::Vec2Array *textureArray1 = new osg::Vec2Array;
	textureArray1->push_back(osg::Vec2(0.0f, 1.0f));
	textureArray1->push_back(osg::Vec2(0.0f, 0.0f));
	textureArray1->push_back(osg::Vec2(1.0f, 0.0f));
	textureArray1->push_back(osg::Vec2(1.0f, 1.0f));
	osg::Texture2D *texture1 = new osg::Texture2D;
	texture1->setImage(osgDB::readImageFile("Data/EnvWall.bmp"));
	texture1->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
	texture1->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);

	geometry1->setTexCoordArray(0, textureArray1);
	geometry1->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));
	geometry1->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture1);

	geode1->addDrawable(geometry1);
	
	return geode1;
}

//////////////////////////////////////////////////////////////////////////


//////////////////////////////////////////////////////////////////////////
class RotAxisCallback : public osg::NodeCallback
{
public:
	RotAxisCallback(const osg::Vec3& axis, double rotSpeed = 0.0, double currentAngle = 0.0)
		: _rotAxis(axis), _rotSpeed(rotSpeed), _currentAngle(currentAngle){ }

	virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
	{
		osg::MatrixTransform *rotMT = dynamic_cast<osg::MatrixTransform*>(node);
		if (!rotMT)
			return;
		rotMT->setMatrix(osg::Matrix::rotate(_currentAngle, _rotAxis));
		_currentAngle += _rotSpeed;

		traverse(node, nv);
	}

	void setRotateSpeed(double speed)
	{
		_rotSpeed = speed;
	}

	double getRotateSpeed() const
	{
		return _rotSpeed;
	}


private:
	osg::Vec3		_rotAxis;
	double			_currentAngle;
	double			_rotSpeed;
};


//////////////////////////////////////////////////////////////////////////
class ManipulatorSceneHandler : public osgGA::GUIEventHandler
{
public:
	ManipulatorSceneHandler()
	{
	}

	virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
	{
		osgViewer::Viewer *viewer = dynamic_cast<osgViewer::Viewer*>(&aa);
		if (!viewer)
			return false;
		if (!viewer->getSceneData())
			return false;
		if (ea.getHandled()) 
			return false;

		osg::Group *root = viewer->getSceneData()->asGroup();

		switch(ea.getEventType())
		{
		case(osgGA::GUIEventAdapter::KEYDOWN):
			{
				if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Left)
				{
					if (!g_RotY|| !g_ReflectRotY)
						return false;

					RotAxisCallback *rotCallback = dynamic_cast<RotAxisCallback*>(g_RotY->getUpdateCallback());
					RotAxisCallback *rotCallbackReflect = dynamic_cast<RotAxisCallback*>(g_ReflectRotY->getUpdateCallback());
					if (!rotCallback || !rotCallbackReflect)
						return false;

					double speed = rotCallback->getRotateSpeed();
					speed -= 0.02;
					rotCallback->setRotateSpeed(speed);
					
					speed = rotCallbackReflect->getRotateSpeed();
					speed -= 0.02;
					rotCallbackReflect->setRotateSpeed(speed);			
				}

				if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Right)
				{
					if (!g_RotY|| !g_ReflectRotY)
						return false;

					RotAxisCallback *rotCallback = dynamic_cast<RotAxisCallback*>(g_RotY->getUpdateCallback());
					RotAxisCallback *rotCallbackReflect = dynamic_cast<RotAxisCallback*>(g_ReflectRotY->getUpdateCallback());
					if (!rotCallback || !rotCallbackReflect)
						return false;

					double speed = rotCallback->getRotateSpeed();
					speed += 0.02;
					rotCallback->setRotateSpeed(speed);

					speed = rotCallbackReflect->getRotateSpeed();
					speed += 0.02;
					rotCallbackReflect->setRotateSpeed(speed);		
				}

				if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Up)
				{
					if (!g_RotX|| !g_ReflectRotX)
						return false;

					RotAxisCallback *rotCallback = dynamic_cast<RotAxisCallback*>(g_RotX->getUpdateCallback());
					RotAxisCallback *rotCallbackReflect = dynamic_cast<RotAxisCallback*>(g_ReflectRotX->getUpdateCallback());
					if (!rotCallback || !rotCallbackReflect)
						return false;

					double speed = rotCallback->getRotateSpeed();
					speed -= 0.02;
					rotCallback->setRotateSpeed(speed);

					speed = rotCallbackReflect->getRotateSpeed();
					speed -= 0.02;
					rotCallbackReflect->setRotateSpeed(speed);		
				}

				if (ea.getKey()== osgGA::GUIEventAdapter::KEY_Down)
				{
					if (!g_RotX|| !g_ReflectRotX)
						return false;

					RotAxisCallback *rotCallback = dynamic_cast<RotAxisCallback*>(g_RotX->getUpdateCallback());
					RotAxisCallback *rotCallbackReflect = dynamic_cast<RotAxisCallback*>(g_ReflectRotX->getUpdateCallback());
					if (!rotCallback || !rotCallbackReflect)
						return false;

					double speed = rotCallback->getRotateSpeed();
					speed += 0.02;
					rotCallback->setRotateSpeed(speed);

					speed = rotCallbackReflect->getRotateSpeed();
					speed += 0.02;
					rotCallbackReflect->setRotateSpeed(speed);		
				}

				if (ea.getKey()== osgGA::GUIEventAdapter::KEY_Page_Up)
				{	
					if (!g_Trans || !g_ReflectTrans)
						return false;

					osg::Matrix transMatrix = g_Trans->getMatrix();
					transMatrix.setTrans(transMatrix.getTrans() + osg::Vec3(0, 0.1, 0));
					g_Trans->setMatrix(transMatrix);

					osg::Matrix reflectTransMatrix = g_ReflectTrans->getMatrix();
					reflectTransMatrix.setTrans(reflectTransMatrix.getTrans() + osg::Vec3(0, 0.1, 0));
					g_ReflectTrans->setMatrix(reflectTransMatrix);
				}

				if (ea.getKey()== osgGA::GUIEventAdapter::KEY_Page_Down)
				{
					if (!g_Trans || !g_ReflectTrans)
						return false;

					osg::Matrix transMatrix = g_Trans->getMatrix();
					transMatrix.setTrans(transMatrix.getTrans() + osg::Vec3(0, -0.1, 0));
					g_Trans->setMatrix(transMatrix);

					osg::Matrix reflectTransMatrix = g_ReflectTrans->getMatrix();
					reflectTransMatrix.setTrans(reflectTransMatrix.getTrans() + osg::Vec3(0, -0.1, 0));
					g_ReflectTrans->setMatrix(reflectTransMatrix);
				}

				if (ea.getKey()== osgGA::GUIEventAdapter::KEY_A)
				{
					if (!g_ZoomMT)
						return false;

					osg::Matrix transMatrix = g_ZoomMT->getMatrix();
					transMatrix.setTrans(transMatrix.getTrans() + osg::Vec3(0, 0, -0.1));
					g_ZoomMT->setMatrix(transMatrix);
				}

				if (ea.getKey()== osgGA::GUIEventAdapter::KEY_Z)
				{
					if (!g_ZoomMT)
						return false;

					osg::Matrix transMatrix = g_ZoomMT->getMatrix();
					transMatrix.setTrans(transMatrix.getTrans() + osg::Vec3(0, 0, 0.1));
					g_ZoomMT->setMatrix(transMatrix);
				}
			}
		default: break;
		}
		return false;
	}
};

//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////


class ViewerWidget : public QWidget, public osgViewer::Viewer
{
public:
	ViewerWidget(osg::Node *scene = NULL)
	{
		QWidget* renderWidget = getRenderWidget( createGraphicsWindow(0,0,640,480), scene);

		QVBoxLayout* layout = new QVBoxLayout;
		layout->addWidget(renderWidget);
		layout->setContentsMargins(0, 0, 0, 1);
		setLayout( layout );

		connect( &_timer, SIGNAL(timeout()), this, SLOT(update()) );
		_timer.start( 10 );
	}

	QWidget* getRenderWidget( osgQt::GraphicsWindowQt* gw, osg::Node* scene )
	{
		osg::Camera* camera = this->getCamera();
		camera->setGraphicsContext( gw );

		const osg::GraphicsContext::Traits* traits = gw->getTraits();

		camera->setClearColor( osg::Vec4(0.2f, 0.5f, 1.0f, 1.0f) );
		camera->setViewport( new osg::Viewport(0, 0, traits->width, traits->height) );
		camera->setProjectionMatrixAsPerspective(45.0f, static_cast<double>(traits->width)/static_cast<double>(traits->height), 0.1f, 100.0f );
		camera->setViewMatrixAsLookAt(osg::Vec3d(0, 0, 1), osg::Vec3d(0, 0, 0), osg::Vec3d(0, 1, 0));
		unsigned int clearMask = camera->getClearMask();  
		camera->setClearMask(clearMask | GL_STENCIL_BUFFER_BIT); 

		this->setSceneData( scene );
		this->addEventHandler(new ManipulatorSceneHandler);
		return gw->getGLWidget();
	}

	osgQt::GraphicsWindowQt* createGraphicsWindow( int x, int y, int w, int h, const std::string& name="", bool windowDecoration=false )
	{
		osg::DisplaySettings* ds = osg::DisplaySettings::instance().get();
		osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
		traits->windowName = name;
		traits->windowDecoration = windowDecoration;
		traits->x = x;
		traits->y = y;
		traits->width = w;
		traits->height = h;
		traits->doubleBuffer = true;
		traits->alpha = ds->getMinimumNumAlphaBits();
		traits->stencil = ds->getMinimumNumStencilBits();
		traits->sampleBuffers = ds->getMultiSamples();
		traits->samples = ds->getNumMultiSamples();

		return new osgQt::GraphicsWindowQt(traits.get());
	}

	virtual void paintEvent( QPaintEvent* event )
	{ 
		frame(); 
	}

protected:

	QTimer _timer;
};


osg::Node*	buildScene()
{
	osg::Group *root = new osg::Group;

	osg::Light *light = new osg::Light;
	light->setAmbient(osg::Vec4(LightAmb[0], LightAmb[1], LightAmb[2], LightAmb[3]));
	light->setDiffuse(osg::Vec4(LightDif[0], LightDif[1], LightDif[2], LightDif[3]));
	light->setPosition(osg::Vec4(LightPos[0], LightPos[1], LightPos[2], LightPos[3]));
	light->setLightNum(0);
	osg::LightSource *lightSource = new osg::LightSource;
	lightSource->setLight(light);

	osg::MatrixTransform *tiltMT = new osg::MatrixTransform;
	g_ZoomMT = tiltMT;
	tiltMT->setMatrix(osg::Matrix::translate(0.0f, -0.6f, -7.0f));

	tiltMT->addChild(lightSource);
	//创建模板缓冲区中的镜面(不可见)
	//深度测试关闭意味着深度测试总是通过
	osg::Geode *stencilFloorGeode = createFloor();
	osg::Stencil *floorStencil = new osg::Stencil;
	floorStencil->setFunction(osg::Stencil::ALWAYS, 1, 1);
	floorStencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::REPLACE);
	osg::ColorMask *colorMask1 = new osg::ColorMask(0, 0, 0, 0);
	stencilFloorGeode->getOrCreateStateSet()->setMode(GL_DEPTH_TEST, false);
	stencilFloorGeode->getOrCreateStateSet()->setAttribute(colorMask1, osg::StateAttribute::ON);
	stencilFloorGeode->getOrCreateStateSet()->setAttributeAndModes(floorStencil);
	stencilFloorGeode->getOrCreateStateSet()->setMode(GL_LIGHTING, false);

	//创建镜面中的球体(球体镜像)
	osg::MatrixTransform *reflectScaleMT = new osg::MatrixTransform;
	reflectScaleMT->setMatrix(osg::Matrix::scale(1.0, -1.0, 1.0));
	reflectScaleMT->addChild(lightSource);
	osg::MatrixTransform *reflectTransMT = new osg::MatrixTransform;
	reflectTransMT->setMatrix(osg::Matrix::translate(0.0, 2.0, 0.0));
	g_ReflectTrans = reflectTransMT;
	osg::MatrixTransform *reflectRotateX = new osg::MatrixTransform;
	g_ReflectRotX = reflectRotateX;
	reflectRotateX->addUpdateCallback(new RotAxisCallback(osg::X_AXIS));
	osg::MatrixTransform *reflectRotateY = new osg::MatrixTransform;
	g_ReflectRotY = reflectRotateY;
	reflectRotateY->addUpdateCallback(new RotAxisCallback(osg::Y_AXIS));
	osg::Group *reflectionBall = createSphere();
	
	osg::Stencil *stencilBall  = new osg::Stencil;
	stencilBall->setFunction(osg::Stencil::EQUAL, 1, 1);
	stencilBall->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::KEEP);

	osg::ClipPlane *clipPlane = new osg::ClipPlane(0, 0.0, -1.0, 0.0, 0.0);

	reflectionBall->getOrCreateStateSet()->setAttributeAndModes(stencilBall, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
	reflectionBall->getOrCreateStateSet()->setAttributeAndModes(clipPlane);
	
	reflectScaleMT->addChild(reflectTransMT);
	reflectTransMT->addChild(reflectRotateX);
	reflectRotateX->addChild(reflectRotateY);
	reflectRotateY->addChild(reflectionBall);

	//创建颜色缓冲区镜面(可见)
	osg::Geode *colorBufferFloor  = createFloor();
	osg::BlendFunc *blendFunc = new osg::BlendFunc(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::ONE_MINUS_SRC_ALPHA);
	osg::Geometry *floorGeometry = colorBufferFloor->getDrawable(0)->asGeometry();
	if (floorGeometry)
	{
		osg::Vec4Array *colorArray = new osg::Vec4Array;
		colorArray->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 0.8f));
		floorGeometry->setColorArray(colorArray, osg::Array::BIND_OVERALL);
		floorGeometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
		floorGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
	}
	osg::MatrixTransform *transMT = new osg::MatrixTransform;
	transMT->setMatrix(osg::Matrix::translate(0, 2, 0));
	g_Trans = transMT;
	osg::MatrixTransform *rotateX = new osg::MatrixTransform;
	g_RotX = rotateX;
	rotateX->addUpdateCallback(new RotAxisCallback(osg::X_AXIS));
	osg::MatrixTransform *rotateY = new osg::MatrixTransform;
	g_RotY = rotateY;
	rotateY->addUpdateCallback(new RotAxisCallback(osg::Y_AXIS));
	osg::Group *realBall = createSphere();
	transMT->addChild(rotateX);
	rotateX->addChild(rotateY);
	rotateY->addChild(realBall);

	//所有部分添加到场景节点
	root->addChild(tiltMT);
	tiltMT->addChild(stencilFloorGeode);
	tiltMT->addChild(reflectScaleMT);
	tiltMT->addChild(colorBufferFloor);
	tiltMT->addChild(transMT);

	return root;
}



int main( int argc, char** argv )
{
	QApplication app(argc, argv);
	ViewerWidget* viewWidget = new ViewerWidget(buildScene());
	viewWidget->setGeometry( 100, 100, 640, 480 );
	viewWidget->show();
	return app.exec();
}