osg学习如何根据视口对象自动调整视点位置和距离

 osgGA/CameraManipulator.cpp

    
 void CameraManipulator::computeHomePosition(const osg::Camera *camera, bool useBoundingBox)
    
 {
    
     double dist = 3.5f * boundingSphere.radius();
    
     if (camera)
    
     {
    
  
    
         // try to compute dist from frustum
    
         double left,right,bottom,top,zNear,zFar;
    
         if (camera->getProjectionMatrixAsFrustum(left,right,bottom,top,zNear,zFar))
    
         {
    
             double vertical2 = fabs(right - left