Animating a Quadruped

Animating a Multi-legged Character

Working with Motion-Capture Data

 

Autodesk 3ds Max Tutorials > Character Animation Tutorials > Biped Beyond the Basics > Animating a Multi-legged Character > 

Adding Extra Limbs

In this lesson, you'll add bones as appendages to a biped, creating a pair of wings, and learn how to animate them.

Note that the extra limbs become 3ds Max objects, and must be animated with rotations. They do not respond to Biped Figure mode or inverse kinematics.

Set up the lesson:

1. Reset 3ds Max.
2. Open cs4_tut_quad_WallyStart.max from \tutorials\character_animation\quadruped.

   

This file shows Wally in See-Through mode. He has wings, but no means of moving them. You'll remedy that in the next few procedures.

Add the wing bones:

1. In the Left viewport, use Region Zoom to focus on the area around the wings.

   

   The view after zooming.

2. Open the Create panel, and click the Systems button.
3. On the Object Type rollout, turn on Bones. In the Bone Parameters rollout > Bone Objects group, set the Width and Height values to 3.0.

   

   In this case, the Width and Height defaults of 10.0 would produce clumsy-looking bones.

4. On the IK Chain Assignment rollout, make sure Assign To Children is turned off before making bones. Off is the default.
5. Add a set of four bones along the leading edge of the wing. See the following illustration. Create the three long bones, so the last bone is at the tip of the wing, then right-click to finish. The fourth bone will appear as a little knob at the end.

   

   Bones along the leading edge of the wing.

6. Turn on Rotate. In the Front viewport, select Bone01 and rotate it about –35 degrees around the Z-axis.

   

7. Working between the Front and Left viewports, use Move, Rotate, and Scale to adjust the bones so they match the following illustrations.

   

8. Save the scene as MyWally01.max.

Mirror the bones:

Now that one wing is created, you'll mirror the wing and set the proper IK solution.

1. In the Front viewport, drag a selection window around the wing bones you just created.

   

2. On the main toolbar, click the Mirror Selected Objects button to display the Mirror dialog.
3. In the Mirror dialog, in the Clone Selection group, choose Copy. In the Mirror Axis group, set Offset to –35.5 on the X axis. Click OK.

   This creates four matching bones on the other side, named Bone05 through Bone08.

   

4. Select Bone01. This is the base bone on the right wing.
5. From the Animation menu, choose IK Solvers > HI Solver, and click the end bone, Bone04.

   

6. Select the base bone on the left wing.
7. Apply the HI Solver to this bone and click the end bone on the left wing.

   

   Both wings have IK solutions.

   NoteIt's a good idea to test the bend by moving the end effectors. It might be necessary to adjust the Swivel Angle from the Motion panel in the IK Solver Properties rollout.
8. Save the scene as MyWally02.max.

Add dummies to control the wings:

You'll now add two dummy objects to act as control handles for the wings.

1. Open the Create panel, and click the Helpers button.
2. Click Dummy. In the Top viewport, drag to create a small dummy object near the tip of the right wing.
3. In the Front viewport, move the dummy object up to the wing tip.

   

4. Hold down the Shift key and move a copy of the dummy over to the tip of the left wing.

   

   The dummies will be used as control handles instead of the end effectors.

5. Select both dummy objects and the base bones of the left and right wing. On the main toolbar, turn on Select And Link, and then drag a link to Wally Biped Spine2.

   

   If you move the biped, the wing bones and dummies will move along with the rest of the model.

   NoteAfter linking, you may notice the bones rotate out of alignment with the mesh. This is fixed by adjusting the Swivel Angle.
6. Select IK Chain01 and link it to Dummy01. Repeat this step by selecting IK Chain02 and linking it to Dummy02.
7. Select IK Chain01 and open the Motion panel.
8. In the IK Solver Properties rollout, enter –51 in the Swivel Angle field.
9. Select IK Chain02 and set its Swivel Angle to 296.
10. Save the scene as MyWally03.max.

Animate the wings:

1. Move the time slider to frame 5, and turn on Auto Key.
2. From the Front viewport, select Dummy01. Move it down and to the right a little.

   

3. Move the time slider to frame 10, and move Dummy01 down and a little to the left.

   

4. On the time bar, select the key at frame 5. Hold down the Shift key and drag a copy to frame 15. Repeat this step with the key at frame 0, and drag it to frame 20.
5. Repeat the previous steps with Dummy02.

   When you're done, you've animated Wally flapping his wings.

6. To see a finished product, open cs4_tut_quad_WallyFinal.max, or view wallyshow320.avi. It shows a version of Wally that flaps his wings and lifts off.

   

After building the character model, a biped was added and adjusted to fit properly. Next, extra bones to control the wings were added. The Physique modifier was applied to Wally, and envelopes were adjusted to enclose the mesh. Finally, the character was animated.