Tutorial 1: Biped and Physique

Lesson 2: Modifying the Biped Structure in Figure Mode

Figure mode lets you change the structure of the biped, independent of any animation. The biped's basic structure and pose are stored in a figure file (.fig). Once you have saved a .fig file, you can activate Figure mode and apply that skeleton and pose to any biped. The animation adapts its motion keys to changes in the bipedal structure automatically when you leave Figure mode. The same animation that works for a tiny or skinny character can work for a big or round one. You can apply any .bip file to any biped.

Use Figure mode to fit a biped inside a character's geometry. Position the mesh and skeleton so they overlap at the pelvis, and then rotate, scale or move the biped body parts into place.

In Figure mode, you can use the same Structure rollout parameters you use during biped creation. You can change the overall height, the number of fingers, toes, and the number of spine links. You can also add a tail, or ponytail. You can specify an armless biped.

In this lesson, you will use Figure mode to change the structure of your biped. Then you will play back the animation to see how Biped has adapted keys to accommodate the changes in the character's proportions.

Viewing Biped creation parameters

  1. In the 3DS MAX main menu, choose File > Open cs3_tut01_mod_figmode.max.

    This is the same animation you were just using (banana.bip) with a few objects in the scene to give a sense of scale.

  2. Select any part of the biped in the front perspective viewport.

  3. Click the Motion panel.

  4. Close the Track Selection and Keyframing rollouts, and open the Structure rollout.

    As you see, controls on the Structure rollout are the same as on the Create Biped rollout. These are the biped's creation parameters. The parameters are not animatable, so their controls are disabled unless you are in Figure mode.

Changing Biped creation parameters

  1. On the General rollout, click Figure Mode.

    The controls on the Structure rollout become active.

  2. Depending on your zoom factor and viewport layout, the biped figure might disappear from view when you click Figure mode. If necessary, click Zoom Extents All to center the biped in your viewports. Zoom back in as necessary to frame the biped in the viewport.

  3. Decrease the Height value by about half, then turn off figure mode.

    The size of footsteps decreases to accommodate the smaller biped. Play the animation, if you like.

    Footsteps adapt to smaller biped

  4. Turn on Figure mode again, and double the biped height. Turn off Figure mode and zoom to see the biped.

    The animation works on the larger biped as well.

  5. Turn on Figure mode again, and change the number of Leg links to 4.

    Each leg now has an extra bone that does not correspond to human anatomy.

    You can make any kind of change to the biped body parts: the animation will still work.

  6. Select one of the biped's thighs in the perspective viewport.

  7. Open the Track Selection Rollout and choose Symmetrical.

    This adds the other thigh to the selection. Now both thighs are selected.

  8. On the main toolbar, click Select and Non-Uniform Scale from the scale flyout.

    A warning appears which cautions about using Non-Uniform Scale.

  9. Click Yes to continue.

  10. Using the Transform gizmo, scale the thighs in X so they are elongated.

  11. Turn off Figure mode.

    The biped returns to its animated pose in the current frame. Biped scales footsteps to match the biped's new dimensions. The animation accommodates the double-jointed legs.

    Animation adapts to changes in structure

Scaling and Rotating parts of the biped

You can make some interesting characters by scaling and rotating the various biped pieces. To get some ideas, examine the sample .fig files in cstudio/characters/figure.

  1. Turn on Figure mode.

  2. On the Motion panel click Load File and open gator_up.fig.

    This is the figure file of an alligator that walks upright. It's too small for the scene.

  3. On the Structure rollout, increase the Height to 200.

    The gator increases in size.

    Scaling the biped using figure mode Height

Making Jaws with Ponytails

You can create bunny ears, and alligator jaws by rotating and moving the ponytails. The alligator's jaw uses ponytails that are shifted to the front of the head.

  1. Choose File > Reset to reset 3D Studio MAX.

  2. Go to Create > Systems and click Biped.

  3. In the Front viewport, create a biped.

  4. On the Motion Panel, turn on Figure mode.

  5. On the Structure rollout, change Ponytail1 Links to 5.

  6. Change Ponytail2 Links to 5.

    Tip: Press Tab to move to the next field.

  7. Zoom the left viewport.

  8. Select Bip01 Ponytail1 and Bip01 Ponytail2 by pressing H and selecting each name.

  9. Move the ponytails so they are in front of the biped's face.

  10. Rotate the ponytails about Z, so the ponytails point out from the face.

  11. Select one ponytail and rotate it 180 degrees about X.

  12. Move the ponytails apart so your biped resembles the one in the illustration.

    Ponytails rotated and moved to the front of the head to create alligator jaws

    You can rotate and scale the different links to make the lips for convex or concave. Use PAGE UP and PAGE DOWN to move quickly through the hierarchy.

    You can even add modifiers to the ponytail links to taper the bones. However, only the biped structure is saved in the .fig file. If you add extra bones or add modifiers to the biped objects, save a .max file.

    Once you leave figure mode, you can animate the jaw using rotations. The ponytails are automatically linked to the head and will move and rotate with its movement.

Completing the Gator figure

Next you'll give the gator a swayback by rotating the spline elements in Figure mode.

  1. In Figure mode, turn on Bend Links mode on the General rollout.

    Bend Links mode passes the rotations of links up the skeleton, affecting several links with one rotation.

  2. Select and rotate Bip01 Spine about Z a few degrees.

  3. Select the next link down (Bip01 Spine1) and rotate it a few degrees.

  4. Turn Bend Links mode off.

  5. Press PAGE DOWN to move down the chain to the next link.

    Bip01 Spine2 is selected.

  6. If any part of the legs becomes selected, press the ALT key and click the legs to remove them from the selection set.

  7. Rotate Bip01 Spine2 up to define the slouching posture.

    Notice the first two links are not affected by the rotation.

  8. Finish off the alligator by shortening the spine links, legs, and arms. Rotate the arms up away from the torso.

    Rotate the arms up away from the body

    You use an outstretched pose to adjust the biped file inside a mesh.

Save your work

  1. Turn on Figure mode, if it is off.

  2. On the Motion panel, on the General rollout, click Save File.

    When Figure mode is active, Save File saves a .fig file. Otherwise Save File saves a .bip file.

  3. Name the file mygator.fig, and then click Save.

    The biped's structure, size, and pose are stored as a biped figure file (.fig).

  4. From the 3DS MAX menu Choose File > Save to save your 3DS MAX file as mygator.max.