/** \page gui Graphical User Interface The graphical user interface allows the user to navigate through the world, and recieve information about the simulation. \section gazebo_gui_nav Movement and Other Controlls Movement through the world is accomplished via a combination of the mouse and keyboard. The mouse is used to free-look when when left mouse button is pressed. Only the pitch and yaw of the camera is controllable. Translation through the world is accomplished using the W,A,S,D,Q,E keys: - W : forward - A : left - S : back - D : right - Q : up - E : down Other key bindings: - SPACE : Pause / start the physics engine. When in STEP mode, cause the physics engine to increment one step. - TAB : Show / hide the heads up display. - ESC : Quit - [ : Switch to previous camera, if available - ] : Switch to next camera, if available - T : Start / stop stepping of the physics engine. - H : Dispaly help \section gazebo_gui_info \image html hud.png "Gazebo Heads Up Display" */