Click the mouse button to create a point and start the
second part of the trajectory, then click again to create a third
part and so on. Double-click to end the trajectory.
A Fly Through layer is added to the Map Layers pane.
The trajectory represents a route that you can follow visually when
the Fly Through is started. The trajectory is displayed in the Fly
Through in relief, and a Fly Through button is added to all the currently open 3D View toolbars.