//    Instruction Example :      track.rotation.interpolation.set (long)


        screen.resolution.set (512,384)

        screen.set (BACK)
          pattern.display ("avo\bubble.gif")
        screen.end ()

        @camera=camera.create (0,0,-200,0,0,0)
        @viewport=viewport.create ()
        viewport.camera.set (@viewport,@camera)
        viewport.display (@viewport)

        @cube1=mesh.cube.create (50)
        @cube2=mesh.cube.create (50)

        @track1=track.create (TRACK_LOOP)
          track.rotation.interpolation.set (INTERP_LINEAR)
          init (-50)
        track.end ()

        @track2=track.create (TRACK_LOOP_SMOOTH)
          track.rotation.interpolation.set (INTERP_TCBSPLINE)
          init (50)
        track.end ()

        @sequence1=sequence.play (@track1,@cube1)
        @sequence2=sequence.play (@track2,@cube2)

        screen.set (FRONT)
          text.display ("Press a key to exit.",CENTER,350)
        screen.end ()

        keyboard.wait ()

        script.stop ()

        procedure init (%pos)
          track.key.set (0)
          track.key.position.set (%pos,0,0)
          track.key.rotation.set (0,0,0)
          track.key.set (1)
          track.key.rotation.set (0,0,0)
          track.key.set (2)
          track.key.rotation.set (0,180,180)
          track.key.set (3)
          track.key.rotation.set (0,270,0)
          track.key.set (4)
          track.key.rotation.set (0,0,0)
        end procedure