roslaunch gazebo_ros empty_world.launch 启动失败问题

问题如下：

解决方法如下：

在终端输入代码

export LIBGL_ALWAYS_SOFTWARE=1

或者：  used the indigo, and I also met this problem occasionally.when I input  rosrunch gazebo_ros willowgarage_world.launch  terminal always report the error:no namespace found ! Finally, I solve this problem.My solution is input sudo apt-get install ros-indigo-gazebo-ros-pkgs ros-indigo-gazebo-ros-control  in the terminal. Maybe you need update some packages. If you want to receive more detail informations, please go to the >  http://gazebosim.org/tutorials?tut=ro...  . Believe maybe this can help you!