OsgOsg实例实现环境雾效果(Qt5.14.2+osgEarht3.6.5+win10)No5EnvironmentFog

相关资料：

https://blog.csdn.net/wb175208/article/details/88692393     osg 雾效果

https://blog.csdn.net/xiaoyuwang1994/article/details/105921857/     实现osgEarth三维仿真场景模型雾的效果的添加解决方法

代码实例：

.pro

QT       += core gui widgets
TARGET = TestOsgQt
TEMPLATE = app
DEFINES += QT_DEPRECATED_WARNINGS
CONFIG += c++11

SOURCES += \
        main.cpp

HEADERS +=

OsgDir = D:\\RuanJian\\osg365R
CONFIG(release, debug|release) {
        LIBS += -L$${OsgDir}/lib/ -losgDB -losgViewer -lOpenThreads -losgAnimation -losg \
                                  -losgEarth -losgEarthAnnotation -losgEarthFeatures -losgEarthSymbology -losgEarthUtil \
                                  -losgQOpenGL -losgUtil -losgText -losgTerrain -losgSim \
                                  -losgShadow -losgParticle -losgManipulator -losgGA -losgFX \
                                  -losgWidget
} else {
        LIBS += -L$${OsgDir}/debug/lib/ -losgDBd -losgViewerd -lOpenThreadsd -losgAnimationd -losgd \
                                  -losgEarthd -losgEarthAnnotationd -losgEarthFeaturesd -losgEarthSymbologyd -losgEarthUtild \
                                  -losgQOpenGLd -losgUtild -losgTextd -losgTerraind -losgSimd \
                                  -losgShadowd -losgParticled -losgManipulatord -losgGAd -losgFXd \
}


INCLUDEPATH += $${OsgDir}/include
DEPENDPATH += $${OsgDir}/include

main.cpp

    #include <QApplication>

#include <osg/Node>
#include <osg/Group>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/Texture2D>
#include <osg/StateSet>
#include <osg/PositionAttitudeTransform>
#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgParticle/PrecipitationEffect>
// 雨雪效果
#include <osg/MatrixTransform>
// 粒子效果
#include <osgParticle/PrecipitationEffect>
#include <osgParticle/Particle>
#include <osgParticle/LinearInterpolator>
#include <osgParticle/ParticleSystem>
#include <osgParticle/RandomRateCounter>
#include <osgParticle/PointPlacer>
#include <osgParticle/RadialShooter>
#include <osgParticle/ModularEmitter>
#include <osgParticle/ParticleSystemUpdater>
#include <osgParticle/ModularProgram>
#include <osgUtil/Optimizer>
#include <osgUtil/Simplifier>
// 雾
#include <osg/Fog>
#include <osgDB/ReadFile>
#include <osgViewer/Viewer>
#include <osg/StateSet>
#include <osg/StateAttribute>
#include <osgViewer/ViewerEventHandlers>
#include <osgWidget/ViewerEventHandlers>

class FogCallBack :    public osg::StateSet::Callback {
public:
    FogCallBack();
    ~FogCallBack();

    virtual void operator() (osg::StateSet* ss, osg::NodeVisitor*nv)override;
};

FogCallBack::FogCallBack() {
}


FogCallBack::~FogCallBack() {
}

void FogCallBack::operator() (osg::StateSet* ss, osg::NodeVisitor*nv) {
    osg::Fog* fog = dynamic_cast<osg::Fog*>(ss->getAttribute(osg::StateAttribute::FOG));
    if (fog){
        float start = fog->getStart();
        if (start<fog->getEnd()){
            fog->setStart(start + 2.0);
        }
    }
}

int main(int argc, char *argv[])
{
    // ---------------------雾-----------------------
    osg::ref_ptr<osg::Group> root = new osg::Group;
    osg::ref_ptr<osg::Node> cowNode = osgDB::readNodeFile("D:\\osgFiles\\lz.osg");
    root->addChild(cowNode);

    osg::ref_ptr<osg::Fog> fog = new osg::Fog;
    fog->setColor(osg::Vec4(1.0, 1.0, 1.0, 0.5));//设置颜色
    fog->setStart(1.0);//设置雾效的近距离
    fog->setEnd(2000.0);//设置雾效的远距离
    fog->setDensity(10.0);//设置雾效的密度
    fog->setMode(osg::Fog::LINEAR);//设置雾效的类型-线型

    root->getOrCreateStateSet()->setUpdateCallback(new FogCallBack);
    root->getOrCreateStateSet()->setAttributeAndModes(fog.get(), osg::StateAttribute::ON| osg::StateAttribute::OVERRIDE);

    osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer();
    viewer->addEventHandler(new osgViewer::WindowSizeHandler());
    viewer->addEventHandler(new osgViewer::StatsHandler());
    // **********************************设置窗口*******************************
    //设置图形环境特性
    osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits();
    traits->x = 100;
    traits->y = 200;
    traits->width = 600;
    traits->height = 500;
    traits->windowDecoration = true;
    traits->doubleBuffer = true;
    traits->sharedContext = 0;
    // 创建图形环境特性
    osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
    if (gc.valid())
    {
        osg::notify(osg::INFO)<<"  GraphicsWindow has been created successfully."<<std::endl;

        //清除窗口颜色及清除颜色和深度缓冲
        gc->setClearColor(osg::Vec4f(0.2f,0.2f,0.6f,1.0f));
        gc->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    }
    else
    {
        osg::notify(osg::NOTICE)<<"  GraphicsWindow has not been created successfully."<<std::endl;
    }
    //设置视口
    viewer->getCamera()->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
    //设置图形环境
    viewer->getCamera()->setGraphicsContext(gc.get());
    viewer->setSceneData( root );
    return viewer->run();
}