Scenario

A basketball player character passes a ball to his teammate.

1. Select the first player’s hands, and then the basketball.
2. Parent constrain the ball to the hands, making sure that Maintain Offset is on and the weight is set to 1 in the constraint options.
3. In the Channel Box, set keys for the weights of the first player’s hands.
   Note

   When the basketball is selected, the parent constraint and all its target weights appear in the Channel Box.

4. Animate the arms of the first player so that they appear to be throwing the ball.
5. At the point in the first character’s animation where he is to let go of the ball, set a key on the ball and on the weights of the hands.
6. Change the blend weight to 1, and key the blend weight.
7. Advance one frame along the timeline.
8. Set the weight of the first player’s hands to 0, and set the blend weight to 0.
9. Key the hand weights and the blend weight.
10. Keyframe the ball as it is thrown from the first player to the second player.
11. When the ball reaches the position where the second player catches it, parent constrain the ball to the hands of the second player, making sure that Maintain Offset is on and the weight is 0 in the constraint options.
12. Key the weights of the second player’s hands and that of the blend weight.
13. Advance one frame along the timeline.
14. Set the blend weight to 1 and the second player’s hands’ weights to 1.
15. Key the blend weight and the weights of the second player’s hands again.
16. Animate the second player.
    Note

    If you want to ensure that the transitions between the blend weights are clean (no interpolation), set the tangent types of the weights to Stepped.