Creating Biped Rigs

Creating the Biped or Dog Leg Rig

1. Modify the proportioning guide to match your character's proportions (see Setting Up the Biped Guides).

2. If you have more than one guide in the scene, select the biped or biped dog leg guide for which you want to create a rig.

3. Choose Create Character Rig from Biped Guide or Create Character Rig from Biped Dog Leg Guide from the Animate toolbar.

4. In the Make Biped or Make Biped Dog Leg dialog box that appears, set up the rig elements as you need. The sections following this procedure provide a summary of the options on each property page in the dialog box.

5. Click OK and a new skeleton rig based on the guide's proportions and the options you selected is created.

   

   A	Head (null): controls rotation and translation of head. See Setting Up the Head, Neck, and Ears for more information.
   B	Ears: curves are chains driven by springs. Cubes control ears' rotation. See Spring Operators for Tail, Ear, and Belly Rig Controls for more information.
   C	Chest: controls rotation and translation of spine.
   D	Upper body (outer square): controls rotation and translation of upper body.
   E	Foot (outer cube): controls rotation and translation of foot.
   F	Foot roll (inner cube): controls rotation angle for step and heel roll. See Using the Biped or Biped Dog Leg Controls for more information.
   G	Toe (cube at tip): controls offset from the foot in rotation.
   H	Hips (inner square): controls rotation and translation of hips.
   I	Leg up-vectors (pyramids): control resolution plane of legs for IK.
   J	Hand Grab (small cube): controls rotation of fingers and thumb for making fists and claws. See Animating the Fingers and Hands for more information.
   K	Hand (cube): controls rotation and translation of hand.
   L	Arm up-vectors (pyramids): control resolution plane of arms for IK.

   Tip

   • The biped dog leg foot controls are the same as for the quadruped rig — see Creating the Rig.

   • The Toe (tip) control allows the foot to point in a particular direction or rotate without the toes going below this control object. Select the Toe control and rotate it or translate it to control the foot placement. Unlike manipulating the Foot control, the third bone won't go under the Toe control object.

   • You can also create a separate tail element that you can then use with any rig that you create, such as to create some fantastical creature using a biped dog leg rig. See Creating a Tail for more information.

   • You can hide the proportional guide after you've created the rig so that it's easier to see the rig.

   • It's a good idea to save a copy of the character's proportional guide in case you want to change the rigging options later.

6. After the rig is created, the Biped or Biped Dog Leg Controls appear. These let you scale the spine and upper body volume, as well as set the foot roll angle (and leg extension for the biped dog leg rig).

   See Using the Biped or Biped Dog Leg Controls for more information.

7. Envelope the body geometry to the rig.

   To envelope this character, weight it to the envelope_group group found in the rig's model. The contents change based on the rigging options.

   If you have multiple envelope objects, weight all of them to the full envelope group. This makes it easier to paint weights across the multiple surfaces.

   

8. Translate and rotate the appropriate rig controls and key them to animate the parts of the skeleton.

   See Tips for Using the Rigs for more information on using the rigs.

   ImportantWhen you animate the rig, make sure to turn off both constraint and child transform compensations! To do this, you can deactivate the CnsComp and ChldComp buttons on the Constrain panel. If you don't do this, you will reposition the constraints on the rig.

Setting Up the Torso Spine

The options on the Chest page in the Make Biped/Biped Dog Leg dialog box let you select the way you want the spine to be set up in the torso area.

The Torso spine type can be either quaternion or regular skeleton. Both the spine types are compatible in all combinations of rigs and with the shadow rigs.

You can also choose what type of control icons you want for the chest or upper body: squares or cubes.

For details on each parameter, see Chest [Properties Reference].

Here are two examples of some possible combinations:

Creating a Belly Control

The options on the Belly page in the Make Biped/Biped Dog Leg dialog box let you create a belly control and set the weighting for it. This control may be useful for animating a character that has a large belly or paunch.

For details on each parameter, see Belly.

Setting Up the Head, Neck, and Ears

The options on the Head page in the Make Biped/Biped Dog Leg dialog box let you select the way you want the head and neck to be set up, including the creation of ear spring controls, which are useful for making humanoid creatures. The neck can be either a regular skeleton or a quaternion spine.

For details on each parameter, see Head.

Here are two examples of some possible combinations:

Setting Up the Arms Fingers, and Toes

The options on the Limbs page in the Make Biped/Biped Dog Leg dialog box let you select the way the arms, fingers, and toes are created and animated. You can choose the type of arm rotation order (YZX or XYZ), whether or not the arms are manipulated symmetrically, and whether the arms are children of the shoulders or the hips.

You can also choose whether to use 2D or 3D chains for the fingers, and whether to create 2- or 3-bone toes.

For details on each parameter, see Limbs.

Setting the Roll Division

The options on the Roll Division page in the in the Make Biped/Biped Dog Leg dialog box allow you to choose how you want the skeleton's envelope to be weighted at a more refined level when the bone is rotated (rolled). You can set the roll divisions for the forearms, upper-arms (biceps), and thighs.

For details on each parameter, see Roll Division.

The roll division reduces the pinching that occurs when appendages with simple bone structure roll. These quaternion-based options create a set of nulls, based on the number of subdivisions that you specify, to distribute the weighting along the bone.

Six roll-division nulls created for refined envelope weighting on the forearm. The forearm roll division allows for more rotation at the wrist than the elbow.

Selecting Volume Controls for the Skin (Envelope)

When you're animating a rig, you need to take the final body envelope into consideration. This helps you animate appropriately, especially when the body is very large or unusually shaped.

To help you visualize and estimate the body's volume with the rig, you can select the options on the Skin page in the Make Biped/Biped Dog Leg dialog box. Based on the yellow splines you set up with the proportional guide (see Setting Up the Biped Guides), these options create a series of controls and nulls that approximate the body sliding and compressing over the skeleton.

For details on each parameter, see Skin.

Volume controls are created based on the yellow splines in the guide that you adjusted to match the body's geometry

Using these controls, you can allow a character to reach extreme poses more easily than by weighting alone.

After you adjust the volume controls' position, rotation, and scale to get them into the poses that work optimally for your character, you should key these values. If you need to return to the original position where the control splines were generated (such as to modify or reapply the envelope), you can apply an action source to the rig called DefaultPose (see Action Sources).

Creating Shadow Rigs

Shadow rigs, sometimes referred to as export skeletons, are simpler rigs that are constrained to the more complex main rig that is used for animating the character. When you generate the main rig, you can create a shadow rig at the same time.

Shadow rigs are usually used for exporting animation, such as to a game or crowd engine or other 3D software programs. To transfer the animation from the complex rig to the shadow rig, plot the animation while the shadow rig is still constrained in place to the complex rig. Then you can export the shadow rig or just its animation.

On the Shadow Rigs page in the Make Biped/Biped Dog Leg dialog box, you can select the Type of shadow rig to create.

For details on each parameter, see Shadow Rigs.

Here are two examples of some possible options:

On the left, a box shadow rig on top of the main rig.

On the right, a box shadow rig with IK arms and legs.

When you animate the rig, the shadow rig follows along. You can then plot the animation on to the shadow rig, remove the constraints between the rigs, and the shadow rig is ready to be exported.

For information on plotting, see Plotting (Baking) Animation.

On the left, the rig is animated. Because the shadow rig on the right is constrained to it, the shadow rig is also animated.

If the animation is plotted to the shadow rig, the constraints between the two rigs can be removed. The shadow rig can then be exported.

Using the Biped or Biped Dog Leg Controls

After the rig is created, the Biped or Biped Dog Leg Controls are displayed. You can use these to adjust the scale of the spine, neck, and upper body volume, as well as set the foot roll angle.

Foot roll angle control is rotated to lift the heel when it's at a certain angle.

With the biped dog leg rig, there are extra sliders that control the locking of the leg extension control (the middle box in the three foot controls) for the foot roll.

For details on each parameter of these controls, see Biped Controls or Biped Dog Leg Controls.

TipIf you close these Controls, you can find them again (a custom parameter set) in the explorer under the Biped or Biped_DogLeg model's node.

Animating and Enveloping the Rig

• Apply the envelope to the character using the envelope_group group found in the rig's model. The contents change based on the rigging options you have selected. If you have multiple envelope objects, weight all of them to the full envelope group. This makes it easier to paint weights across the multiple surfaces.

  

• To animate the rig, translate and rotate the appropriate rig controls and key them to animate the parts of the skeleton.

  However, make sure to turn off both constraint and child transform compensations! You can deactivate the CnsComp and ChldComp buttons on the Constrain panel. Otherwise, you end up repositioning the constraints on the rig.

Animating the Fingers and Hands

Under each hand's root node, you can find a custom parameter set that contains sliders for rotating each finger bone in the hand. This set is also available by clicking the Sliders button on the Hands page in the synoptic view (select an element and press F3).

You can also use the buttons on the Hands page to easily select and pose the hands. As well, you can apply action sources that can relax, make a fist, or spread the fingers on each hand.

Making a Fist or Claw

There is a small cube control (called RHand_Grab or LHand_Grab) created at the base of the fingers on each hand. When you rotate it on Z, the fingers are formed into a clenching or grabbing fist. This makes it easy to quickly animate a grabbing hand or a claw.

Rotate (in Z) the cube (Hand Grab control) at the base of the fingers to make the fingers and thumb curl into a claw or fist formation.

Features to Help You Use the Rig

There are a number of features in the rig that can help you use it.

Synoptic View

There is a synoptic view available to control the rig, which you can open by selecting any part of the rig and pressing F3. This lets you easily select and key the rig, reset it, and have detailed control over the hands.

When you scale the rig, the synoptic's control systems adapt to the new proportions, so you can still select items.

Character Key Sets

Each rig control element has several character key sets to define which parts of the character are keyed, plotted, and posed by the synoptic view. These character key sets can help you quickly key the different controls in a rig.

For more information, see Keying with Character Key Sets.

Action Sources

The biped rigs contain various action sources to help pose the hands or return to the default pose. For example, if you need to return to the rig's original position (such as to modify or reapply the envelope), you can apply the action source called DefaultPose to the rig.

To apply an action, select it from the rig's Mixer > Sources > Actions folder and choose Actions Apply Action (see Restoring (Applying) the Animation in Action Sources to an Object for more information).

Tips for Using the Rigs

The following tips provide information about how to set up and use the rig.