Why "export GAZEBO_MODEL_PATH=..." fail gazebo?

$export GAZEBO_MODEL_PATH=~/models
$gazebo
then gazebo doesn’t work and show anything in the scene. Setting the environment variable GAZEBO_MODEL_PATH always occur this !
Note:$echo $GAZEBO_MODEL_PATH before setting is empty
Why?

Hi @bingxue. This site is meant mainly for discussions about Gazebo. For technical questions like this one, please go to http://answers.gazebosim.org/ .