The main controls for playing animation in MotionBuilder are found in the Transport Controls.

To play animation, use one of the following methods:

• In the Transport Controls, click Play to play the animation, and Stop to stop the animation.
  

  Play Controls found in the Transport Controls A. Stop B. Play

• Press Ctrl-Spacebar to play the animation, and press Ctrl-Spacebar again to stop the animation.
• J-drag in the Viewer window or along a timeline to jog the animation. See Jogging animation.