Making the Biped Look at Objects

Set up this lesson:

1. Open lookat_tabletennis_start.max.

2. Play the animation in the Perspective viewport.

   The ball bounces back and forth over the net four times, then the ball bounces up and done in place four times.

   

   Ball bounces, but biped isn't watching.

Make the biped look at a target:

Suppose you want to animate the biped watching the ball going over the net, but not follow the bounce in place. By animating Target Blend, you can create this effect.

1. In the Perspective viewport, select the head of the biped. Open the Motion panel.

2. Open the Key Info rollout and expand the Head bar. On the Key Info rollout, click Set Key.

   The Target Blend field becomes available.

3. Click the Select Look At Target arrow, below the Target Blend spinner, then click the table tennis ball in the viewport.

   The name pingpongball appears in the field.

4. Change Target Blend to 1.

   The biped is now looking at the ball.

   

   The biped looks at the ball automatically.

5. Play the animation.

   The biped watches the bouncing ball intently.

   

   The biped's head follows the movement of the ball.

Make the biped look around:

In this procedure, you make the biped look around as the ball bounces in place.

1. Move the time slider to frame 200.

   At frame 200, the period begins where the ball bounces in place.

2. On the Key Info rollout, click Set Key and set the Target Blend to 0.

3. Move to frame 199. On the Key Info rollout, click Set Key and set the Target Blend to 1.

   Between frames 0 and 199, the Target Blend parameter is set to 1; at frame 200, it changes to 0. Setting these keys this way is a way to control interpolation. You could also change the interpolation for the key at frame 200 to a step value coming in, and then not bother setting the other key.

4. Move the time slider to frame 210. Rotate the head so it’s looking away from the bouncing ball.

5. Add more rotation keys to the biped's head until frame 300.

   

   Rotate the biped head freely when Target Blend is zero.

6. Play the animation.

   The biped looks at the ball bouncing over the net, but then switches focus to something else.

   Note: You can’t select multiple objects within a single animation. If you need to do that, try using a List Controller with several LookAt constraints, then animate the weights of the list items.

7. Save your work as mylookat_tabletennis.max, or open lookat_tabletennis_final.max for comparison.