Hi

Working with ros and trying to run gazebo but I am running in to a balck screen issue. first I run $ roscore in a new terminal I run $ rosrun gazebo_ros gazebo

gazebo opens but I just get a black or blank screen. in a new terminal I run

$ rostopic list

and all I get back is /rosout /rosout_agg. I'm following this book and I don't think this is suppose to happen; especially when I run the last command. the book says I should get this back

$ rostopic list

/gazebo/linkstates
/gazebo/modelstates
/gazebo/parameterdescriptions
/gazebo/parameterupdates
/gazebo/setlinkstate
/gazebo/setmodelstate