multiplier
Values greater than 1.0 increase the speed that the animation is played relative to the scene clock speed; values less than 1.0 decrease the speed. A value of 1.0 plays the animation at the speed in the glTF animation mapped to the scene clock speed. For example, if the scene is played at 2x real-time, a two-second glTF animation will play in one second even if multiplier is 1.0.