Interacting with Objects

Interacting with Objects

Making Feet Follow Objects

 

Autodesk 3ds Max Tutorials > Character Animation Tutorials > Biped Beyond the Basics > Interacting with Objects > 

Making a Hand Follow an Object

In this lesson, you'll make a biped’s hand follow an animated object.

When a biped’s hand must interact with an object, there are two methods you can use to create the animation:

• Animate the hand, then link the object to the hand with Select And Link, or
• Animate the object, and use IK settings to make the hand follow the object.

The second method has some practical advantages, which are illustrated with this lesson.

Set up for this lesson:

1. Open the file ironing_start.max.

   

   This file features a character named Wilson standing in front of an ironing board.

2. Play the animation. The iron is animated to move over the cloth on the ironing board.

   This character already has a biped with Physique applied to it. To work with the character, you'll hide the mesh and unhide the biped.

3. Choose the named selection set Wilson Biped. When the warning dialog appears, click Yes.

   The biped appears in the scene.

4. Choose the named selection set Wilson Mesh.
5. On the Display panel, click Hide Selected.

   This leaves the biped in the scene without the character mesh.

   

Pose the hands:

1. Go to the Motion panel.
2. Go to frame 0.
3. Turn on Auto Key.
4. Using Select And Move and Select And Rotate, pose the right hand to hold the iron handle. Look at the hand from different angles to ensure it is gripping the handle. Don't be concerned if the fingers pass through the handle slightly.
   TipYou can also right-click in a viewport and choose Move or Rotate from the quad menu.

   

   If you have difficulty with this step, open the file ironing_handpose.max. This file contains the biped already posed with its right hand on the iron.

5. With Auto Key turned on, position the left hand to hold down the fabric.

   

Link the right hand to the iron:

1. Select the right hand.
2. On the Motion panel > Key Info rollout, expand the IK bar.
3. Click Select IK Object, and click the iron.

   The object name Steam Iron appears to the left of the Select IK Object button.

4. Choose the Object option just above the Select IK Object button.
5. Change IK Blend to 1.0.
6. Play the animation. The hand follows the iron.

   

   You could have created a similar animation by linking the iron to the hand with Select And Link, then animating the hand. However, this type of animation is limited. For example, if you later bent the biped’s spine so he could get a closer look at his ironing, the hand would move with the spine and sink into the ironing board. With IK linking, the hands will stay put when you rotate the spine.

   Right now, if you bent the spine, the right hand would stay on the iron but the left hand would move. You can keep the left hand from moving by anchoring it to the ironing board.

Link the left hand to the ironing board:

1. Select the left hand.
2. Click Select IK Object, and click the ironing board.

   The object name Ironing Board appears to the left of the Select IK Object button.

3. Choose the Object option just above the Select IK Object button.
4. Change IK Blend to 1.0.

Bend the biped over:

1. Select all the biped’s spine links.
2. Make sure you’re at frame 0.
3. In the Key Info rollout, click Set Key.
4. Go to frame 40.
5. Make sure Auto Key is turned on.
6. Rotate the biped’s spine links so the biped bends slightly forward.

   

   The biped’s hands stay in place when the biped bends forward.

7. Go to frame 80, and rotate the spine links to make the biped stand up straight again.
8. Animate the biped’s head every 30-40 frames to make him look at the iron as he works.

   

Unhide the character:

1. From the Named Selection Sets list, choose Wilson Mesh. When the warning dialog appears, click Yes. The character mesh appears in the scene.

   

2. From the Named Selection Sets list, choose Wilson Biped.
3. Go to the Display panel and click Hide Selected.

   The biped is hidden, leaving only the character mesh.

   

4. Play the animation. Wilson irons the cloth and bends over to take a closer look.
5. Save your work in the file my_wilson_ironing.max.

   You can find a completed version of this animation in the file ironing_complete.max.