Animating the Biped with Freeform Animation

Biped Quickstart

Combining Motions with the Motion Mixer

 

Autodesk 3ds Max Tutorials > Character Animation Tutorials > Biped Quickstart > 

Animating the Biped with Footsteps

Now that you're familiar with freeform animation, you'll learn the basics of footstep animation. Footstep animation only controls the placement of the biped's feet. In this lesson, you'll create a footstep animation where Dr. X walks for eight steps.

You can see what your animation should look like by viewing the preview animation, drxwalk.avi, in the tutorials\character_animation\quick_start folder.

Set up the lesson:

1. Reload cs4_qs_drX03.max from the tutorials\character_animation\quick_start folder.

   This scene contains Dr. X with Physique applied to the mesh, and all envelopes adjusted. The mesh is ready for animation.

   

2. Press the H key and choose DoctorX from the Select Object list, then click the Select button.
3. In the Perspective viewport, right-click the mesh and choose Hide Selection from the quad menu.

   Hiding the mesh makes it easier to select the biped and test the animation. This is especially true if you have a highly detailed mesh.

   

4. Press the H key again and choose DrX Biped, the center of mass, from the Select Object list, then click the Select button.

Create the footsteps:

Now you'll make Dr. X walk forward in a straight line.

1. Open the Motion panel.
2. On the Biped rollout, turn on Footstep Mode.

   Using the rollouts that now display, you'll create footsteps for Dr. X.

3. On the Footstep Creation rollout, click the Create Multiple Footsteps button.

   The Create Multiple Footsteps: Walk dialog opens.

   

4. In the General group, increase the Number Of Footsteps to 8, then click OK.
5. In the Footstep Operations rollout, click Create Keys For Inactive Footsteps.

   

   When the footstep keys are created, Dr. X changes his pose.

6. Right-click in the Perspective viewport, and then click the Play Animation button. You can also scrub the time slider to examine the animation more closely.

   

   By just watching the biped walk, you can tell that Dr. X's walk doesn't look right. You can see that the feet are too close together, and his arms are straight down at his side. In addition, the shoes and hands will collide or intersect with other body parts when the mesh is displayed again. Next, you'll do some fine tuning to make Dr. X's walk look better.

Fine-tune the animation:

In this part of the lesson, you'll make a few adjustments to clean up the animation.

1. If you don't see footsteps outlined in front of Dr. X, do the following:
   • On the Biped rollout, click the gray expansion bar below the buttons. Additional buttons appear.
   • In the Display group, click the Show Footsteps And Numbers button.
     Note If the footsteps still fail to display, click the Show Footsteps And Numbers button and hold until you see the button flyout. Choose the Show Footsteps And Numbers button from the flyout.
2. In the Perspective viewport, zoom out, if necessary, to see all the footsteps. Drag a selection window around all the footsteps. Be sure to include the two footsteps under the biped's feet.

   The footsteps turn white after they're selected.

   NoteBecause you're working in Footstep mode, only the footsteps can be selected, so you can drag over the biped without fear of selecting other objects.
3. On the Footstep Operations rollout, turn off Length and increase the Scale to 2.5.

   

   The biped's stance widens to more closely match how it looked in Figure mode. However, now that the stance is wider, the hands will intersect the legs when the mesh is unhidden. You'll fix that next.

Rotate the arms:

With the wider stance, the hands intersect the legs as they swing past. Now you'll do a little freeform animation to give the arms some clearance.

1. On the Biped rollout, turn off Footstep mode.

   Now you can rotate Dr. X's arms.

2. Press the H key and select DrX Biped L Upperarm.
3. In the Track Selection rollout, click the Symmetrical button.

   Notice the keys in the time line. At each of the keys, you'll rotate the arms.

4. Turn on Auto Key and Key Mode Toggle, then click the right arrow on the time slider.

   The time slider jumps to frame 30.

5. On the main toolbar, click the Rotate button.
6. On the Coordinate display, in the Y field, enter 12.

   The arms are rotated out away from the body.

   

   TipSometimes the arms will rotate in parallel, instead of in opposite directions. If this happens to you, select and rotate each arm individually.
7. Continue clicking the right arrow on the time slider to jump to the next key and repeat the same amount of rotation for each key on the time line.

   Don't forget the key at frame 0.

8. Turn off Auto Key to end the animation process.
9. Play the animation.

   

Save the motion in a BIP file:

You can save the footstep motion for later use in other scenes.

1. On the Biped rollout, choose Save File.

   The Save File dialog displays.

2. Specify a folder where you are storing your motion files, such as a new tutorials\character_animation\motions folder.
3. Enter my_DrXWalk as the file name, and click Save.

   The footstep motion is saved in the BIP file.

Prepare for playing or rendering:

1. Press the H key. In the Select From Scene dialog, click Select All button, and then click Select.
2. Right-click the biped and choose Hide Selection.

   The biped is now hidden.

3. Right-click again, and choose Unhide By Name from the quad menu.

   The Unhide Objects dialog displays.

4. Select DoctorX from the list and click Unhide.

   Dr. X's mesh is unhidden.

5. Click the mesh to select it.
6. On the Modify panel, make sure the MeshSmooth modifier is turned on (the light bulb icon should be white).
7. Click the Perspective viewport and then click the Play Animation button.

   

8. Save the scene as my_drx03_footsteps.max.

   You can find a finished version of this scene in the file cs4_qs_drX03_footsteps.max.