Scenario

A character walks, looks around, stops, and then removes his hat from his head and places it on a table nearby.

1. Select the character’s head, and then the hat.
2. Parent constrain the hat to the head, making sure that Maintain Offset is on and the weight is set to 1 in the constraint options.
3. Select the hat, and then select the head’s weight in the Channel Box.
   NoteWhen the hat is selected, the parent constraint and all its target weights appear in the Channel Box.
4. -click the head’s weight and select Key Selected from the menu that appears.
5. Animate the character so that it appears to walk, look around, and then stop.
6. Animate the character’s arm and hand so that it reaches up and takes hold of the hat’s brim.
7. Select the hand, and then the hat.
8. Parent constrain the hat to the hand, making sure that Maintain Offset is on and the weight is set to 0 in the constraint options.
9. Key the weight of the head and the hand. See steps 3 and 4.
10. Advance one frame along the timeline.
11. Set the weight of the head to 0 and the weight of the hand to 1.
12. Key the head and hand weights. See steps 3 and 4.
13. Transform the arm and hand to the position where it appears to be placing the hat on the table.
14. Set the hat’s current position as its rest position.
15. Set the weight of the hand to 0 and key the weight.
16. Animate the hands so that they return to their original positions hanging at the characters sides.
    NoteIf you want to ensure that their is no interpolation between weights (weights switch between 1 and 0 with no blend), set the tangent types of the weights to Stepped.