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。