Notice how the movie defines the 0.0 to 1.0 s and t boundaries. Also, notice how we have illustrated the texture map infinitely repeating in all directions. This shows what happens conceptually when s and t values, specified by the TextureCoordinate node, are outside of the 0.0 to 1.0 range. This indicates the duration of the movie in seconds. It was changed to an SFTime field to be consistent with AudioClip and because it was a more convenient type for performing arithmetic in a script.
Movies tend to be very large and can take a long time to load.
Because loading a movie can be such an expensive operation, implementations might defer loading it until it is scheduled to be played. Content creators should try to help the implementations by setting the MovieTexture's startTime field as early as possible, hopefully allowing the browser enough time to complete the download before the scheduled starting time. So, for example, if you animate a Transform when the user presses a button and play a movie after the animation is done, it is much better to set the startTime of both the animation and the movie based on the time of the button press, rather than waiting to set the MovieTexture's startTime when the first animation is finished. The cycle of a MovieTexture node is the length of time in seconds for one playing of the movie at the specified speed . The speed exposedField indicates how fast the movie shall be played.