//    Instruction Example :      track.material.color.interpolation.set (long,long)


        screen.resolution.set (512,384)

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

        @camera=camera.create (100,70,-200,0,0,0)
        @viewport=viewport.create ()
        viewport.camera.set (@viewport,@camera)
        viewport.display (@viewport)

        @cube=mesh.cube.create (100)
        @material=material.create ()
        mesh.material.set (@cube,@material,MATERIAL_BOTHSIDE)

        mesh.display (@cube)

        @track=track.create (TRACK_LOOP|TRACK_PINGPONG)
          track.material.color.interpolation.set (INTERP_TCBSPLINE,MATERIAL_AMBIENTCOLOR)
          track.key.set (0)
          track.key.material.color.set (0,0,0,MATERIAL_AMBIENTCOLOR)
          track.key.set (2)
          track.key.material.color.set (255,0,0,MATERIAL_AMBIENTCOLOR)
        track.end ()

        @sequence=sequence.play (@track,@material)

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

        keyboard.wait ()

        script.stop ()