The TimeSensor helper lets you add time-based animation controls, such as the start and end frames for a particular object's animation, and looping. Use this helper to split up an object's animation keys over several triggers, to automatically start an animation upon loading the .wrl file, or to make animation endlessly loop.
To assign an object to a TimeSensor helper:
The Time Sensor rollout contains the following options:
Repeats the animation from the start-time frame to the stop-time frame.
Starts the animation so that it will be running when the file is loaded into the browser.
Specifies the range of frames to play.
Lets you select the objects to control with this TimeSensor.
Deletes an object from the list of picked objects.
Adjusts the size of the helper object in the viewports.