OSG学习：阴影代码示例

效果图：

代码示例：

#include <osgViewer/Viewer>

#include <osg/Node>

#include <osg/Geode>

#include <osg/Group>

#include <osg/Camera>

#include <osg/ShapeDrawable>

#include <osg/ComputeBoundsVisitor>

#include <osg/BoundingBox>

#include <osg/BoundingSphere>

#include <osg/AnimationPath>

#include <osgDB/ReadFile>

#include <osgDB/WriteFile>

#include <osgShadow/ShadowedScene>

#include <osgShadow/ShadowVolume>

#include <osgShadow/ShadowTexture>

#include <osgShadow/ShadowMap>

#include <osgShadow/SoftShadowMap>

#include <osgShadow/ParallelSplitShadowMap>

#include <osgUtil/Optimizer>

#include <iostream>

//标识阴影接收对象

const int ReceivesShadowTraversalMask = 0x1;

//标识阴影投影对象

const int CastsShadowTraversalMask = 0x2;

//创建场景数据

osg::ref_ptr<osg::Node> createModel()

{

    osg::Vec3 center(0.0f, 0.0f, 0.0f);

    float radius = 100.0f;

    osg::Vec3 lightPosition(center + osg::Vec3(0.0f, 0.0f, radius));

    osg::ref_ptr<osg::Node> shadower = osgDB::readNodeFile("D:\\OSGmodel\\WKZ005_JZ_24.OSGB");

    shadower->setNodeMask(CastsShadowTraversalMask);

    osg::ref_ptr<osg::Node> shadowed = osgDB::readNodeFile("D:\\OSGmodel\\floor.OSGB");

    shadowed->setNodeMask(ReceivesShadowTraversalMask);

    osg::ref_ptr<osg::Group> group = new osg::Group;

    group->addChild(shadowed.get());

    group->addChild(shadower.get());

    return group.get();

}

//创建一个光照

osg::ref_ptr<osg::Node> createLight(osg::ref_ptr<osg::Node> model)

{

    osg::ComputeBoundsVisitor cbbv;

    model->accept(cbbv);

    osg::BoundingBox bb = cbbv.getBoundingBox();

    osg::Vec4 lightpos;

    lightpos.set(bb.center().x(), bb.center().y(), bb.zMax() + bb.radius()*2.0f, 1.0f);

    osg::ref_ptr<osg::LightSource> ls = new osg::LightSource();

    ls->getLight()->setPosition(lightpos);

    ls->getLight()->setAmbient(osg::Vec4(0.2, 0.2, 0.2, 1.0));

    ls->getLight()->setDiffuse(osg::Vec4(0.8, 0.8, 0.8, 1.0));

    return ls.get();

}

int main()

{

    osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer();

    osg::ref_ptr<osg::Group> root = new osg::Group();

    //创建一个阴影节点，并标识接收对象和投影对象

    osg::ref_ptr<osgShadow::ShadowedScene> shadowedScene = new osgShadow::ShadowedScene();

    shadowedScene->setReceivesShadowTraversalMask(ReceivesShadowTraversalMask);

    shadowedScene->setCastsShadowTraversalMask(CastsShadowTraversalMask);

    //创建阴影纹理

    osg::ref_ptr<osgShadow::ShadowTexture> st = new osgShadow::ShadowTexture();

    //关联阴影纹理

    shadowedScene->setShadowTechnique(st);

    osg::ref_ptr<osg::Node> node = new osg::Node();

    node = createModel();

    //添加场景数据并添加光源

    shadowedScene->addChild(createLight(node.get()));

    shadowedScene->addChild(node.get());

    root->addChild(shadowedScene.get());

    //优化场景数据

    osgUtil::Optimizer optimizer;

    optimizer.optimize(root.get());

    viewer->setSceneData(root.get());

    viewer->realize();

    viewer->run();

    return 0;

}

注：模型的路径需要修改。

附加：图中两个模型下载。