Rigging Process



The following details my personal standard rigging process for bipedal humanoid characters. This is a good place to start for anyone looking to begin rigging from scratch or edit existing rigs.

Process Outline
Naming Conventions: For joints, I use Joint_JointName, for Controls, Control_ControlName. Generally the name is something like LAnkle or SpineBase. The underscore before the side designation makes the part easily renameable. Other node types usually follow the same conventions. When in doubt, make the name as descriptive as possible, you'll save yourself a few headaches later.
 * 1) Cleanup the scene. Many times when you first recieve a scene from a modeler, it will be full of things they've forgotten to delete. To begin, select all of the meshes in the scene and delete the history and freeze their transformations. Failure to do so can result in strange deformations when you start skin weighting as well as unwanted transform nodes in the outliner. Next you'll need to open up the outliner and delete all of the unncessary groups and any stray transform nodes you may encounter. This will help you keep the scene organized as you begin the rigging process. Once you've removed everything unnecessary from the scene and all of the remaining transformations are zeroed out, you're ready to begin step 2.
 * 2) Create the skeleton. You can really begin this anywhere, but generally the legs are a good place to start. In a basic rig, you'll usually want to include Thigh, Knee, Ankle, Ball of Foot, and a Toe joint in the leg, as well as a reverse lock setup. You will also need to parent each leg joint chain to a Root joint, which represents the hips. For the spine I prefer 5 joints, and the neck an additonal 4 joint, with the final joint being placed at the top of the head. Each arm includes a Clavicle, Shoulder, Elbow, and Wrist joint, as well as any finger joints you feel you need to include. Once you've set up the joint chains, make sure they're oriented properly. Problem areas generally include the feet, neck, and any thumb joints you choose to create. You'll also need to create IK handles for the legs, at minimum, but the arms are also a good idea. If you wish, you can make your chracter's spine an IK spline.
 * 3) Create the controls. This is the easy part. All you need to do is create some basic shapes to be used as controls for the character and name them properly. I generally use NURBS Circles and the Text tool, but you can create custom shapes using Maya's various curves tools or download one of the many scripts that will do it for you. Once you've created and named them, move and rotate them into place, freeze their transformations, and delete the history. When in doubt as to where a control should be placed, snap it to joint it's to be controlling (unless you're planning to use pole vectors, then move it out a ways forward (knees) or behind (elbows) the character)
 * 4) Create the rig interactions. This is the intersting part. Here, you'll be constraining all of the various joints to their controls and using set driven keys and the connection editor to build more complicated intereaction. In general, the orient and parent constraints will be your most used. Remember to check maintain offsets. Try to keep things simple, if you encounter a problem you don't know how to solve, move onto one you do know. Each character can present unique problems you may not have encountered before. When in doubt, ask! And if all else fails, GOOGLE!
 * 5) Paint the skin weights. A lot of people consider this the dull part of the job, but it can be fun if you follow a process. First select the base joint of the joint chains you wish to be wighted to (usually, everything but the Reverse Lock setup), then shift select all of the mesh, and use smooth bind. If you so desire, use interactive skin binding instead. This will generate a capsule that will allow to quickly ballpark your skin weights. Important tools you'll find useful during this process include the Remove Unused Influence tool, Paint Skin Weights, Mirror Skin Weights, and the Weight Hammer, all of which are found under Skin>Edit Smooth Skin (put them on a custom shellf! Shift+Ctrl+LMouse). To begin, I reccomend pruning out unnecessary influences by selecting each individual mesh and flooding the influence with a 0 weight, then hitting Remove Unused Influences. This will remove the influence from the paintable influence hieracrhy and Maya will no longer attempt to calculate or add that influence automatically. If you go nuts and remove something you shouldn't have, use Add Influence to put it back. The pruning process can be tedious, but it's worth it in the long run. Once you've cleaned that up, you're pretty much free to paint weight as you like.
 * 6) Cleanup the rig. This generally includes testing all parts to insure functionality and making sure the Global Controller is moving and scaling everything appropriately. Also, cleanup the outliner and remove any unused nodes you may have generated. Note that an empty node is not neccessarily an unused node. Finally, Group all parts of the rig together under one easily identifiable node.

Notes: These are not strict guidelines, and depending on your chracter, your animator's preferences, and your own personal preferences, you may want to change it up. Go for it! Experiement, find new tricks, and build awesome rigs!