第5课时《osg矩阵变换（下）》

一、模型转动

//矩阵变换

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

{

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

    osg::ref_ptr<osg::MatrixTransform> maxT= new osg::MatrixTransform;

    osg::ref_ptr<osg::MatrixTransform> maxTsub1= new osg::MatrixTransform;

    osg::ref_ptr<osg::Node> node= osgDB::readNodeFile("robot.osg");

    //模型沿着Z轴转动

    maxTsub1->addChild(node.get());

    maxTsub1->setMatrix(osg::Matrix::translate(5.0,0.0,0.0));

    maxT->addChild(maxTsub1);

    //回调函数，使用路径回调

    //在模型渲染的过程中，也就是最后一步：viewer.run()，通过回调函数进行相关事件的调用

    maxT->setUpdateCallback(new osg::AnimationPathCallback(osg::Vec3(5.0,0.0,0.0),osg::Z_AXIS,1.0));

    group->addChild(maxT);

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

    return group;

}

二、模型控制类实现模型的平移、旋转、缩放等操作

1.NodeMatrixTransform类

#include <osg/MatrixTransform>

#include <osg/Node>

#include <osg/BoundingSphere>

class  NodeMatrxiTransform : public osg::MatrixTransform

{

public:

    NodeMatrxiTransform(void);

    ~NodeMatrxiTransform(void);

public:

    /**设置当前模型转动方式*/

    void rotating(const osg::Vec3d &pivot, const osg::Vec3d &axis, float angularVelocity);

    /**旋转模型*/

    void toRotate(const osg::Matrix &mat);

    /**旋转模型*/

    void toRotate(float angle, const osg::Vec3f &axis);

    /**缩放模型*/

    void toScale(const osg::Matrix &mat);

    /**缩放模型*/

    void toScale(double &lel);

    /**addsChild方法*/

    void addsChild(osg::Node *node);

    /**将模型移到目的点*/

    void toPosition(osg::Vec3d &pos);

    /**得到模型当前的位置*/

    osg::Vec3d getPosition();

    /**限制模型大小*/

    void adapt(osg::BoundingSphere &sps);

    /**限制模型大小*/

    void adapt(osg::Node *node);

private:

    osg::ref_ptr<osg::MatrixTransform> pat;

    osg::BoundingSphere ps;

    osg::Node * pnode;

    float level;

    osg::Vec3d position;

};

2. NodeMatrixTransform.cpp文件

#include "nodematrxitransform.h"

#define NODE_MATRIX __declspec(dllexport)

NodeMatrxiTransform::NodeMatrxiTransform(void)

{

    pat = new osg::MatrixTransform;

    addChild(pat.get());

    level = 1.0;

    position = osg::Vec3d(0, 0, 0);

}

NodeMatrxiTransform::~NodeMatrxiTransform(void)

{

}

/**设置当前模型转动方式*/

void NodeMatrxiTransform::rotating(const osg::Vec3d &pivot, const osg::Vec3d &axis, float angularVelocity)

{

    setUpdateCallback(new osg::AnimationPathCallback(pivot, axis, angularVelocity));

}

/**旋转模型*/

void NodeMatrxiTransform::toRotate(const osg::Matrix &mat)

{

    pat->setMatrix(mat);

}

/**旋转模型*/

void NodeMatrxiTransform::toRotate(float angle, const osg::Vec3f &axis)

{

    pat->setMatrix(osg::Matrix::rotate(angle, axis));

}

/**缩放模型*/

void NodeMatrxiTransform::toScale(const osg::Matrix &mat)

{

    pat->setMatrix(mat);

}

/**缩放模型*/

void NodeMatrxiTransform::toScale(double &lel)

{

    pat->setMatrix(osg::Matrix::scale(lel, lel, lel));

}

/**addsChild方法*/

void NodeMatrxiTransform::addsChild(osg::Node *node)

{

    pat->addChild(node);

    pnode = node;

    ps = node->getBound();

    osg::notify(osg::NOTICE)<<ps.center().x() << "  " <<ps.center().y() << "  " <<ps.center().z() << std::endl;

}

/**将模型移到目的点*/

void NodeMatrxiTransform::toPosition(osg::Vec3d &pos)

{

    osg::Vec3d cps;

    cps.set(-ps.center().x()*level, -ps.center().y()*level, -ps.center().z()*level);

    pat->setMatrix(osg::Matrix::translate(cps)*osg::Matrix::translate(pos));

    position = pos;

}

/**限制模型大小*/

void NodeMatrxiTransform::adapt(osg::BoundingSphere &sps)

{

    float level = sps.radius()/ps.radius();

    pat->setMatrix(osg::Matrix::scale(level, level, level));

}

/**限制模型大小*/

void NodeMatrxiTransform::adapt(osg::Node * node)

{

    osg::BoundingSphere sps = node->getBound();

    level = sps.radius()/ps.radius();

    pat->setMatrix(osg::Matrix::scale(level, level, level));

}

/**得到当前的位置*/

osg::Vec3d NodeMatrxiTransform::getPosition()

{

    return position;

}

3. 导出dll

TEMPLATE = lib

DEFINES += NODE_MATRIXTRANSFORM

------------------------------------------------------------------

//导出dll库

#if defined(NODE_MATRIXTRANSFORM)

#  define NODE_MATRIXTRANSFORM_EXPORT Q_DECL_EXPORT

#else

#  define NODE_MATRIXTRANSFORM_EXPORT Q_DECL_IMPORT

#endif

4. 引用dll 使用其方法

//pro文件

win32:DEPENDPATH +=C:/OpenSceneGraph/include \

             $$PWD \

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/ -lNodeMatrix
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/ -lNodeMatrixd
else:unix:!macx: LIBS += -L$$PWD/ -lNodeMatrix

//cpp文件

#include "./nodematrixtransform.h"

    osg::ref_ptr<NodeMatrxiTransform> nodeT= new NodeMatrxiTransform;

    nodeT->addsChild(osgDB::readNodeFile("Cow.osg"));

    nodeT->toPosition(osg::Vec3d(10.0, 0.0, 0.0));

    nodeT->adapt(node.get());