用PCL::ModelCoefficients为点云添加圆锥时，参数设置解释

pcl小白在看点云教程的pcl_visualizer_demo.cpp代码，ModelCoefficients为点云添加圆锥时，对其参数设置的参数不是很理解，如下代码

//在其他位置添加基于模型参数的平面及圆锥体
	ModelCoefficients coeffs;
	coeffs.values.push_back(0.0);
	coeffs.values.push_back(0.0);
	coeffs.values.push_back(1.0);
	coeffs.values.push_back(0.0);
	viewer->addPlane(coeffs, "plane");
	coeffs.values.clear();
	coeffs.values.push_back(0.3);
	coeffs.values.push_back(0.3);
	coeffs.values.push_back(0.0);
	coeffs.values.push_back(0.0);
	coeffs.values.push_back(0.5);
	coeffs.values.push_back(0.0);
	coeffs.values.push_back(5.0);                         
	viewer->addCone(coeffs, "cone");
	return viewer;

最终在pcl手册中查到了解释

链接：http://docs.pointclouds.org/trunk/group__visualization.html#gabcd9db6ceafdd6b36b3700df9134272d

其中：Vector3f cone_apex 为圆锥顶点坐标，Vector3f axis_direction为圆锥轴线（顶点指向底面中心的有向线段）的方向和长度。Angle()为α/2（α为圆锥锥角）。