用OpenSceneGraph实现的NeHe OpenGL教程 - 第二十二课
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简介
这节课我们将讨论凹凸纹理技术，使用凹凸纹理可以让物体表面更有质感。本节课实现的其实是一种被称为浮雕纹理的技术(Emboss Bump Mapping)，并不能算真正的凹凸纹理实现方式(It is a Hack)。
光滑的表面它上面各点法线的方向是一致的，凹凸纹理通过扰乱它表面的法线方向，在进行光照计算的时候(像素光照计算)会使得光滑表面产生明暗不同的颜色，从而"欺骗"我们的大脑，让我们以为它的表面是凹凸不平的。凹凸纹理最早是由James F. Blinn在1978年提的
NeHe课程中的实现原理可以参考凹凸纹理随笔， 在开始之前先说明一下NeHe课程中的实现方式：
NeHe教程中通过空格切换在三种模式下进行：
1. 未使用多重纹理(MultiTexture)技术进行凹凸纹理处理
2.使用多重纹理（MultiTexture）技术进行凹凸纹理处理
3.渲染不带凹凸纹理的场景
这三个过程分别对应doMesh1TexelUnits、doMesh1Texe2Units、doMeshNoBumps三个函数。本课只实现了在1情形下的凹凸纹理。2的实现也在源码中，但是未找到对应的OpenGL API，希望知道的读者指点一二。
下面简单说一下Emboss Bump Mapping的实现过程：
浮雕纹理需要对模型表面贴两次纹理，第一次纹理的纹理坐标不进行偏移、第二次的纹理坐标会在光照方向上进行偏移。偏移量的计算方法可以参考PPT Emboss Bump Mapping
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实现
首先和NeHe教程一下初始化我们需要的纹理：
这里面需要使用osg中的Image类和处理Image的ImageUtil中的内容：部分代码如下：
osg::Image *image1 = new osg::Image;
image1 = osgDB::readImageFile("Data/Base.bmp");
texture[0] = new osg::Texture2D;
texture[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
texture[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
texture[0]->setImage(image1);
texture[1] = new osg::Texture2D;
texture[1]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
texture[1]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
texture[1]->setImage(image1); osg::Image *image2 = new osg::Image;
image2 = osgDB::readImageFile("Data/Bump.bmp");
osg::offsetAndScaleImage(image2, osg::Vec4(), osg::Vec4(0.5, 0.5, 0.5, 1)); // RGB值都减半
bump[0] = new osg::Texture2D;
bump[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
bump[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
bump[0]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
bump[0]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
bump[0]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
bump[0]->setImage(image2); osg::Image *image3 = osgDB::readImageFile("Data/Bump.bmp");
osg::offsetAndScaleImage(image3, osg::Vec4(), osg::Vec4(0.5,0.5,0.5,1));
osg::offsetAndScaleImage(image3, osg::Vec4(-128, -128, -128, 1), osg::Vec4(-1,-1,-1,1));
invbump[0] = new osg::Texture2D;
invbump[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
invbump[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
invbump[0]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
invbump[0]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
invbump[0]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
invbump[0]->setImage(image3);为了进行凹凸纹理，我们先设置第一次纹理部分，代码如下：
可以看到这一次贴的纹理的纹理坐标并没有偏移，全部用到了data中的原始数据
osg::Geode* createUpMappingCube()
{
osg::Geode *cubeGeode = new osg::Geode;
osg::Geometry *cubeGeometry = new osg::Geometry;
osg::Vec3Array *vertices = new osg::Vec3Array;
osg::Vec3Array *normals = new osg::Vec3Array;
osg::Vec2Array *texcoords = new osg::Vec2Array;
for (unsigned i = 0; i < 24; ++i)
{
texcoords->push_back(osg::Vec2(data[5*i],data[5*i + 1])); //第一次贴纹理不需要偏移
vertices->push_back(osg::Vec3(data[5*i + 2], data[5*i +3], data[5*i + 4]));
}
cubeGeometry->setVertexArray(vertices);
cubeGeometry->setTexCoordArray(0, texcoords);
cubeGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices->size()));
cubeGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);
cubeGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, bump[1]);
osg::Depth *depth = new osg::Depth(osg::Depth::LEQUAL);
cubeGeometry->getOrCreateStateSet()->setAttributeAndModes(depth);
cubeGeode->addDrawable(cubeGeometry);
return cubeGeode;
}//第二次贴纹理，这里面并没有纹理坐标，因为纹理坐标需要偏移，在回调中计算
osg::Geode* createDownMappingCube()
{
osg::Geode *cubeGeode = new osg::Geode;
osg::Geometry *cubeGeometry = new osg::Geometry;
cubeGeometry->setUpdateCallback(new TextureCallback());
osg::Vec3Array *vertices = new osg::Vec3Array;
for (unsigned i = 0; i < 24; ++i)
{
vertices->push_back(osg::Vec3(data[5*i + 2], data[5*i +3], data[5*i + 4]));
}
cubeGeometry->setVertexArray(vertices);
cubeGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices->size()));
cubeGeode->addDrawable(cubeGeometry);
return cubeGeode;
}接下来看看回调实现：(只给出部分代码)
virtual void update(osg::NodeVisitor* nv, osg::Drawable* drawable)
{
osg::Geometry *geometry = drawable->asGeometry();
if (!geometry)
return;
osg::Vec2Array *textureArray = dynamic_cast(geometry->getTexCoordArray(0));
if(textureArray)
return;
textureArray = new osg::Vec2Array;
osg::Vec3Array *vertices = dynamic_cast(geometry->getVertexArray());
osg::Vec3 lightPos(LightPosition[0], LightPosition[1], LightPosition[2]);
//获取当前模型视图矩阵
osg::Matrix currentModelViewMatrix = computeLocalToWorld(nv->getNodePath()) * g_viewer->getCamera()->getViewMatrix();
//反转模型视图矩阵
osg::Matrix currentInvModelViewerMatrix = osg::Matrix::inverse(currentModelViewMatrix);
//将光源变换到物体建模坐标系下
osg::Vec3 lightInObjectSpace = lightPos * currentInvModelViewerMatrix;
//
for (int i=0; i<4; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
//获取切空间中在S、T轴上的偏移量
double deltaS = orientation * osg::Vec3(1,0,0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
} osg::Switch *switchNode = new osg::Switch;
g_switch = switchNode;
rotateYAxis->addChild(switchNode);
switchNode->addChild(createUpMappingCube());
switchNode->addChild(createDownMappingCube());
switchNode->addChild(createCube()); if (ea.getKey() == osgGA::GUIEventAdapter::KEY_E)
{
if (g_switch->getValue(2) == true)
{
g_switch->setValue(2, false);
}
else
{
g_switch->setValue(2, true);
}
}
附：本课源码(源码中可能存在错误和不足，仅供参考)
#include "../osgNeHe.h"
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
//
const float MaxEmboss = 0.008f;
bool multitextureSupported = false;
bool useMultitexture = true;
osgViewer::View *g_viewer;
osg::Switch *g_switch;
osg::Switch *g_switchMulti;
GLfloat xrot;
GLfloat yrot;
GLfloat xspeed;
GLfloat yspeed;
GLfloat z=-5.0f;
GLuint filter=1;
osg::Texture2D *texture[3];
osg::Texture2D *bump[3];
osg::Texture2D *invbump[3];
osg::Texture2D *glLogo;
osg::Texture2D *multiLogo;
GLfloat LightAmbient[] = { 0.2f, 0.2f, 0.2f};
GLfloat LightDiffuse[] = { 1.0f, 1.0f, 1.0f};
GLfloat LightPosition[] = { 0.0f, 0.0f, 2.0f};
GLfloat data[]=
{
// FRONT FACE
0.0f, 0.0f, -1.0f, -1.0f, +1.0f,
1.0f, 0.0f, +1.0f, -1.0f, +1.0f,
1.0f, 1.0f, +1.0f, +1.0f, +1.0f,
0.0f, 1.0f, -1.0f, +1.0f, +1.0f,
// BACK FACE
1.0f, 0.0f, -1.0f, -1.0f, -1.0f,
1.0f, 1.0f, -1.0f, +1.0f, -1.0f,
0.0f, 1.0f, +1.0f, +1.0f, -1.0f,
0.0f, 0.0f, +1.0f, -1.0f, -1.0f,
// Top Face
0.0f, 1.0f, -1.0f, +1.0f, -1.0f,
0.0f, 0.0f, -1.0f, +1.0f, +1.0f,
1.0f, 0.0f, +1.0f, +1.0f, +1.0f,
1.0f, 1.0f, +1.0f, +1.0f, -1.0f,
// Bottom Face
1.0f, 1.0f, -1.0f, -1.0f, -1.0f,
0.0f, 1.0f, +1.0f, -1.0f, -1.0f,
0.0f, 0.0f, +1.0f, -1.0f, +1.0f,
1.0f, 0.0f, -1.0f, -1.0f, +1.0f,
// Right Face
1.0f, 0.0f, +1.0f, -1.0f, -1.0f,
1.0f, 1.0f, +1.0f, +1.0f, -1.0f,
0.0f, 1.0f, +1.0f, +1.0f, +1.0f,
0.0f, 0.0f, +1.0f, -1.0f, +1.0f,
// Left Face
0.0f, 0.0f, -1.0f, -1.0f, -1.0f,
1.0f, 0.0f, -1.0f, -1.0f, 1.0f,
1.0f, 1.0f, -1.0f, 1.0f, 1.0f,
0.0f, 1.0f, -1.0f, 1.0f, -1.0f
};
//
//FindFirstNamedNodeVisitor用来遍历寻找与指定名称相同的节点
class FindFirstNamedNodeVisitor : public osg::NodeVisitor
{
public:
FindFirstNamedNodeVisitor(const std::string& name):
osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
_name(name), _foundNode(NULL) {}
virtual void apply(osg::Node& node)
{
if (node.getName()==_name)
{
_foundNode = &node;
return;
}
traverse(node);
}
std::string _name;
osg::Node *_foundNode;
};
//
//RotateCallback
class RotateCallback : public osg::NodeCallback
{
public:
RotateCallback(osg::Vec3d rotateAxis, double rotateSpeed) :
osg::NodeCallback(),
_rotateAxis(rotateAxis),
_rotateSpeed(rotateSpeed),
_rotateAngle(0.0)
{
//Nop
}
void setRotateSpeed(double speed)
{
_rotateSpeed = speed;
}
double getRotateSpeed() const
{
return _rotateSpeed;
}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
osg::MatrixTransform *currentMT = dynamic_cast(node);
if (currentMT)
{
//获取当前的平移位置
osg::Vec3d currentTranslate = currentMT->getMatrix().getTrans();
osg::Matrix newMatrix = osg::Matrix::rotate(_rotateAngle, _rotateAxis) * osg::Matrix::translate(currentTranslate);
currentMT->setMatrix(newMatrix);
_rotateAngle += _rotateSpeed;
}
traverse(node, nv);
}
private:
osg::Vec3d _rotateAxis; //旋转轴
double _rotateSpeed; //旋转速度
double _rotateAngle; //当前旋转的角度
};
//
//
class ManipulatorSceneHandler : public osgGA::GUIEventHandler
{
public:
ManipulatorSceneHandler()
{
}
virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
osgViewer::Viewer *viewer = dynamic_cast(&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)
{
FindFirstNamedNodeVisitor fnv("yRotMT");
root->accept(fnv);
osg::Node *mtNode = fnv._foundNode;
osg::MatrixTransform *yRotMT = dynamic_cast(mtNode);
if (!yRotMT)
return false;
RotateCallback *rotCallback = dynamic_cast(yRotMT->getUpdateCallback());
if (!rotCallback)
return false;
double speed = rotCallback->getRotateSpeed();
speed += 0.02;
rotCallback->setRotateSpeed(speed);
}
if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Right)
{
FindFirstNamedNodeVisitor fnv("yRotMT");
root->accept(fnv);
osg::Node *mtNode = fnv._foundNode;
osg::MatrixTransform *yRotMT = dynamic_cast(mtNode);
if (!yRotMT)
return false;
RotateCallback *rotCallback = dynamic_cast(yRotMT->getUpdateCallback());
if (!rotCallback)
return false;
double speed = rotCallback->getRotateSpeed();
speed -= 0.02;
rotCallback->setRotateSpeed(speed);
}
if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Up)
{
FindFirstNamedNodeVisitor fnv("xRotMT");
root->accept(fnv);
osg::Node *mtNode = fnv._foundNode;
osg::MatrixTransform *xRotMT = dynamic_cast(mtNode);
if (!xRotMT)
return false;
RotateCallback *rotCallback = dynamic_cast(xRotMT->getUpdateCallback());
if (!rotCallback)
return false;
double speed = rotCallback->getRotateSpeed();
speed += 0.02;
rotCallback->setRotateSpeed(speed);
}
if (ea.getKey()== osgGA::GUIEventAdapter::KEY_Down)
{
FindFirstNamedNodeVisitor fnv("xRotMT");
root->accept(fnv);
osg::Node *mtNode = fnv._foundNode;
osg::MatrixTransform *xRotMT = dynamic_cast(mtNode);
if (!xRotMT)
return false;
RotateCallback *rotCallback = dynamic_cast(xRotMT->getUpdateCallback());
if (!rotCallback)
return false;
double speed = rotCallback->getRotateSpeed();
speed -= 0.02;
rotCallback->setRotateSpeed(speed);
}
if (ea.getKey() == osgGA::GUIEventAdapter::KEY_E)
{
if (g_switch->getValue(2) == true)
{
g_switch->setValue(2, false);
}
else
{
g_switch->setValue(2, true);
}
}
}
default: break;
}
return false;
}
};
//
class ViewerWidget : public QWidget, public osgViewer::Viewer
{
public:
ViewerWidget(osg::Node *scene = NULL)
{
QWidget* renderWidget = getRenderWidget( createGraphicsWindow(0,0,100,100), 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(0.0, 0.0, 0.0, 0.5) );
camera->setClearDepth(1.0);
camera->setViewport( new osg::Viewport(0, 0, traits->width, traits->height) );
camera->setProjectionMatrixAsPerspective(45.0f, static_cast(traits->width)/static_cast(traits->height), 0.1f, 100.0f );
camera->setViewMatrixAsLookAt(osg::Vec3d(0, 0, 1), osg::Vec3d(0, 0, 0), osg::Vec3d(0, 1, 0));
this->setSceneData( scene );
addEventHandler(new ManipulatorSceneHandler);
g_viewer = this;
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 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;
};
//
//创建纹理：代码中只是用到第二个纹理bump[1]和invbmp[1]
void initTextures()
{
osg::Image *image1 = new osg::Image;
image1 = osgDB::readImageFile("Data/Base.bmp");
texture[0] = new osg::Texture2D;
texture[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
texture[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
texture[0]->setImage(image1);
texture[1] = new osg::Texture2D;
texture[1]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
texture[1]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
texture[1]->setImage(image1);
texture[2] = new osg::Texture2D;
texture[2]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
texture[2]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_NEAREST);
texture[2]->setImage(image1);
osg::Image *image2 = new osg::Image;
image2 = osgDB::readImageFile("Data/Bump.bmp");
osg::offsetAndScaleImage(image2, osg::Vec4(), osg::Vec4(0.5, 0.5, 0.5, 1));
bump[0] = new osg::Texture2D;
bump[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
bump[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
bump[0]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
bump[0]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
bump[0]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
bump[0]->setImage(image2);
bump[1] = new osg::Texture2D;
bump[1]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
bump[1]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
bump[1]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
bump[1]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
bump[1]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
bump[1]->setImage(image2);
bump[2] = new osg::Texture2D;
bump[2]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
bump[2]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_NEAREST);
bump[2]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
bump[2]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
bump[2]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
bump[2]->setImage(image2);
osg::Image *image3 = osgDB::readImageFile("Data/Bump.bmp");
osg::offsetAndScaleImage(image3, osg::Vec4(), osg::Vec4(0.5,0.5,0.5,1));
osg::offsetAndScaleImage(image3, osg::Vec4(-128, -128, -128, 1), osg::Vec4(-1,-1,-1,1));
invbump[0] = new osg::Texture2D;
invbump[0]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::NEAREST);
invbump[0]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::NEAREST);
invbump[0]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
invbump[0]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
invbump[0]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
invbump[0]->setImage(image3);
invbump[1] = new osg::Texture2D;
invbump[1]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
invbump[1]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
invbump[1]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
invbump[1]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
invbump[1]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
invbump[1]->setImage(image3);
invbump[2] = new osg::Texture2D;
invbump[2]->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
invbump[2]->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR_MIPMAP_NEAREST);
invbump[2]->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
invbump[2]->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
invbump[2]->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
invbump[2]->setImage(image3);
osg::Image *glLogoAlpha = osgDB::readImageFile("Data/OpenGL_ALPHA.bmp");
osg::Image *glLogoImage = osgDB::readImageFile("Data/OpenGL.bmp");
osg::Image *glLogoCombo = new osg::Image;
glLogoCombo->allocateImage(glLogoImage->s(), glLogoImage->t(), 1, GL_RGBA, glLogoImage->getDataType());
unsigned char *comboData = glLogoCombo->data();
for (int i = 0; i < glLogoImage->s() * glLogoImage->t(); ++i)
{
comboData[4*i+3] = glLogoAlpha->data()[i*3];
comboData[4*i] = glLogoImage->data()[i*3];
comboData[4*i+1] = glLogoImage->data()[i*3+1];
comboData[4*i+2] = glLogoImage->data()[i*3+2];
}
glLogo = new osg::Texture2D;
glLogo->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
glLogo->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
glLogo->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
glLogo->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
glLogo->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
glLogo->setImage(glLogoCombo);
osg::Image *glMultiAlpha = osgDB::readImageFile("Data/multi_on_alpha.bmp");
osg::Image *glMultiImage = osgDB::readImageFile("Data/multi_on.bmp");
osg::Image *glMultiCombo = new osg::Image;
glMultiCombo->allocateImage(glLogoImage->s(), glLogoImage->t(), 1, GL_RGBA, glLogoImage->getDataType());
unsigned char *multiComboData = glMultiCombo->data();
for (int i = 0; i < glMultiImage->s() * glMultiImage->t(); ++i)
{
multiComboData[4*i+3] = glMultiAlpha->data()[i*3];
multiComboData[4*i] = glMultiImage->data()[i*3];
multiComboData[4*i+1] = glMultiImage->data()[i*3+1];
multiComboData[4*i+2] = glMultiImage->data()[i*3+2];
}
multiLogo = new osg::Texture2D;
multiLogo->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
multiLogo->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
multiLogo->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP);
multiLogo->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP);
multiLogo->setBorderColor(osg::Vec4(0.5, 0.5, 0.5, 1.0));
multiLogo->setImage(glMultiCombo);
}
osg::Group *createLogo()
{
osg::Group *logoGroup = new osg::Group;
osg::Depth *depth = new osg::Depth(osg::Depth::ALWAYS);
osg::BlendFunc *blendFunc = new osg::BlendFunc(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::ONE_MINUS_SRC_ALPHA);
osg::Geode *logoGeode = new osg::Geode;
osg::Geometry *logoGeometry = new osg::Geometry;
osg::Vec3Array *logoVertices = new osg::Vec3Array;
logoVertices->push_back(osg::Vec3(0.23f, -0.4f,-1.0f));
logoVertices->push_back(osg::Vec3(0.53f, -0.4f,-1.0f));
logoVertices->push_back(osg::Vec3(0.53f, -0.25f,-1.0f));
logoVertices->push_back(osg::Vec3(0.23f, -0.25f,-1.0f));
osg::Vec2Array *textureVertices = new osg::Vec2Array;
textureVertices->push_back(osg::Vec2(0.0f,0.0f));
textureVertices->push_back(osg::Vec2(1.0f,0.0f));
textureVertices->push_back(osg::Vec2(1.0f,1.0f));
textureVertices->push_back(osg::Vec2(0.0f,1.0f));
logoGeometry->setVertexArray(logoVertices);
logoGeometry->setTexCoordArray(0, textureVertices);
logoGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));
logoGeometry->getOrCreateStateSet()->setAttributeAndModes(depth);
logoGeometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
logoGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, glLogo);
logoGeode->addDrawable(logoGeometry);
osg::Geode *multiGeode = new osg::Geode;
osg::Geometry *multiGeometry = new osg::Geometry;
osg::Vec3Array *multiVertices = new osg::Vec3Array;
multiVertices->push_back(osg::Vec3(-0.53f, -0.4f,-1.0f));
multiVertices->push_back(osg::Vec3(-0.33f, -0.4f,-1.0f));
multiVertices->push_back(osg::Vec3(-0.33f, -0.3f,-1.0f));
multiVertices->push_back(osg::Vec3(-0.53f, -0.3f,-1.0f));
osg::Vec2Array *tVertices = new osg::Vec2Array;
textureVertices->push_back(osg::Vec2(0.0f,0.0f));
textureVertices->push_back(osg::Vec2(1.0f,0.0f));
textureVertices->push_back(osg::Vec2(1.0f,1.0f));
textureVertices->push_back(osg::Vec2(0.0f,1.0f));
multiGeometry->setVertexArray(multiVertices);
multiGeometry->setTexCoordArray(0, tVertices);
multiGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));
multiGeometry->getOrCreateStateSet()->setAttributeAndModes(depth);
multiGeometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
multiGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, multiLogo);
multiGeode->addDrawable(multiGeometry);
logoGroup->addChild(logoGeode);
logoGroup->addChild(multiGeode);
return logoGroup;
}
osg::Geode* createCube()
{
osg::Geode *cubeGeode = new osg::Geode;
osg::Geometry *cubeGeometry = new osg::Geometry;
osg::Vec3Array *vertices = new osg::Vec3Array;
osg::Vec3Array *normals = new osg::Vec3Array;
osg::Vec2Array *texcoords = new osg::Vec2Array;
for (unsigned i = 0; i < 24; ++i)
{
texcoords->push_back(osg::Vec2(data[5*i],data[5*i + 1]));
vertices->push_back(osg::Vec3(data[5*i + 2], data[5*i +3], data[5*i + 4]));
}
normals->push_back(osg::Vec3(0.0f, 0.0f, +1.0f));
normals->push_back(osg::Vec3(0.0f, 0.0f,-1.0f));
normals->push_back(osg::Vec3(0.0f, 1.0f, 0.0f));
normals->push_back(osg::Vec3(0.0f,-1.0f, 0.0f));
normals->push_back(osg::Vec3(1.0f, 0.0f, 0.0f));
normals->push_back(osg::Vec3(-1.0f, 0.0f, 0.0f));
cubeGeometry->setVertexArray(vertices);
cubeGeometry->setTexCoordArray(0, texcoords);
cubeGeometry->setNormalArray(normals, osg::Array::BIND_PER_PRIMITIVE_SET);
cubeGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices->size()));
cubeGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, texture[1]);
osg::BlendFunc *blendFunc = new osg::BlendFunc(osg::BlendFunc::DST_COLOR, osg::BlendFunc::SRC_COLOR);
cubeGeometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
osg::Depth *depth = new osg::Depth(osg::Depth::LEQUAL);
cubeGeometry->getOrCreateStateSet()->setAttributeAndModes(depth);
osg::TexEnv *texEnv = new osg::TexEnv(osg::TexEnv::MODULATE);
cubeGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, texEnv);
cubeGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
cubeGeode->addDrawable(cubeGeometry);
return cubeGeode;
}
osg::Geode* createUpMappingCube()
{
osg::Geode *cubeGeode = new osg::Geode;
osg::Geometry *cubeGeometry = new osg::Geometry;
osg::Vec3Array *vertices = new osg::Vec3Array;
osg::Vec3Array *normals = new osg::Vec3Array;
osg::Vec2Array *texcoords = new osg::Vec2Array;
for (unsigned i = 0; i < 24; ++i)
{
texcoords->push_back(osg::Vec2(data[5*i],data[5*i + 1]));
vertices->push_back(osg::Vec3(data[5*i + 2], data[5*i +3], data[5*i + 4]));
}
cubeGeometry->setVertexArray(vertices);
cubeGeometry->setTexCoordArray(0, texcoords);
cubeGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices->size()));
cubeGeometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);
cubeGeometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, bump[1]);
osg::Depth *depth = new osg::Depth(osg::Depth::LEQUAL);
cubeGeometry->getOrCreateStateSet()->setAttributeAndModes(depth);
cubeGeode->addDrawable(cubeGeometry);
return cubeGeode;
}
class TextureCallback : public osg::Drawable::UpdateCallback
{
public:
TextureCallback(){ }
virtual void update(osg::NodeVisitor* nv, osg::Drawable* drawable)
{
osg::Geometry *geometry = drawable->asGeometry();
if (!geometry)
return;
osg::Vec2Array *textureArray = dynamic_cast(geometry->getTexCoordArray(0));
if(textureArray)
return;
textureArray = new osg::Vec2Array;
osg::Vec3Array *vertices = dynamic_cast(geometry->getVertexArray());
osg::Vec3 lightPos(LightPosition[0], LightPosition[1], LightPosition[2]);
osg::Matrix currentModelViewMatrix = computeLocalToWorld(nv->getNodePath()) * g_viewer->getCamera()->getViewMatrix();
osg::Matrix currentInvModelViewerMatrix = osg::Matrix::inverse(currentModelViewMatrix);
osg::Vec3 lightInObjectSpace = lightPos * currentInvModelViewerMatrix;
//
for (int i=0; i<4; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(1,0,0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=4; i<8; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(-1, 0, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=8; i<12; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(1, 0, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,0,-1) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=12; i<16; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, -1, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(-1,0,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=16; i<20; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, 0, -1) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=20; i<24; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, 0, 1) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
geometry->setTexCoordArray(0, textureArray);
geometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, invbump[1]);
geometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);
osg::BlendFunc *blendFunc = new osg::BlendFunc(osg::BlendFunc::ONE, osg::BlendFunc::ONE);
geometry->getOrCreateStateSet()->setAttributeAndModes(blendFunc);
osg::Depth *depth = new osg::Depth(osg::Depth::LEQUAL);
geometry->getOrCreateStateSet()->setAttributeAndModes(depth);
}
};
osg::Geode* createDownMappingCube()
{
osg::Geode *cubeGeode = new osg::Geode;
osg::Geometry *cubeGeometry = new osg::Geometry;
cubeGeometry->setUpdateCallback(new TextureCallback());
osg::Vec3Array *vertices = new osg::Vec3Array;
for (unsigned i = 0; i < 24; ++i)
{
vertices->push_back(osg::Vec3(data[5*i + 2], data[5*i +3], data[5*i + 4]));
}
cubeGeometry->setVertexArray(vertices);
cubeGeometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, vertices->size()));
cubeGeode->addDrawable(cubeGeometry);
return cubeGeode;
}
//
//Method 2：Using MultiTexture to Render
//
//TODO:使用MultiTexture的方式：
// TODO: 未在OpenGL文档中查询到
// glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);
//glTexEnvf (GL_TEXTURE_ENV, GL_COMBINE_RGB_EXT, GL_REPLACE);
//不清楚是否是新的扩展,请读者指点
//
#if 0
class MultiTextureUpdateCallback : public osg::Drawable::UpdateCallback
{
public:
virtual void update(osg::NodeVisitor* nv, osg::Drawable* drawable)
{
osg::Geometry *geometry = drawable->asGeometry();
if (!geometry)
return;
osg::Vec2Array *textureArray = dynamic_cast(geometry->getTexCoordArray(1));
if(textureArray)
return;
textureArray = new osg::Vec2Array;
osg::Vec3Array *vertices = dynamic_cast(geometry->getVertexArray());
osg::Vec3 lightPos(LightPosition[0], LightPosition[1], LightPosition[2]);
osg::Matrix currentModelViewMatrix = computeLocalToWorld(nv->getNodePath()) * g_viewer->getCamera()->getViewMatrix();
osg::Matrix currentInvModelViewerMatrix = osg::Matrix::inverse(currentModelViewMatrix);
osg::Vec3 lightInObjectSpace = lightPos * currentInvModelViewerMatrix;
//
for (int i=0; i<4; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(1,0,0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=4; i<8; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(-1, 0, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=8; i<12; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(1, 0, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,0,-1) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=12; i<16; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, -1, 0) * MaxEmboss;
double deltaT = orientation * osg::Vec3(-1,0,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=16; i<20; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, 0, -1) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
for (int i=20; i<24; i++) {
osg::Vec3 pos = vertices->at(i);
osg::Vec3 orientation = lightInObjectSpace - pos;
orientation.normalize();
double deltaS = orientation * osg::Vec3(0, 0, 1) * MaxEmboss;
double deltaT = orientation * osg::Vec3(0,1,0) * MaxEmboss;
textureArray->push_back(osg::Vec2(data[5*i]+deltaS,data[5*i + 1]+deltaT));
}
geometry->setTexCoordArray(1, textureArray);
geometry->getOrCreateStateSet()->setTextureAttributeAndModes(1, invbump[1]);
osg::TexEnv *tex2Env = new osg::TexEnv(osg::TexEnv::ADD);
geometry->getOrCreateStateSet()->setTextureAttributeAndModes(0, tex2Env);
geometry->getOrCreateStateSet()->setMode(GL_LIGHTING, false);
}
};
#endif
osg::Node* buildScene()
{
initTextures();
osg::Group *root = new osg::Group;
osg::MatrixTransform *zoomMT = new osg::MatrixTransform;
zoomMT->setMatrix(osg::Matrix::translate(0.0, 0.0, -5.0));
osg::MatrixTransform *rotateXAxis = new osg::MatrixTransform;
rotateXAxis->setName("xRotMT");
RotateCallback *xRotCallback = new RotateCallback(osg::X_AXIS, 0.0);
rotateXAxis->setUpdateCallback(xRotCallback);
zoomMT->addChild(rotateXAxis);
osg::MatrixTransform *rotateYAxis = new osg::MatrixTransform;
rotateYAxis->setName("yRotMT");
RotateCallback *yRotCallback = new RotateCallback(osg::Y_AXIS, 0.0);
rotateYAxis->setUpdateCallback(yRotCallback);
rotateXAxis->addChild(rotateYAxis);
osg::Switch *switchNode = new osg::Switch;
g_switch = switchNode;
rotateYAxis->addChild(switchNode);
switchNode->addChild(createUpMappingCube());
switchNode->addChild(createDownMappingCube());
switchNode->addChild(createCube());
root->addChild(zoomMT);
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();
}