Character Setup

In addition to rigging for character models, rigging artists are also responsible for setting up animation controls for anything that is going to be animated. This include vehicles and parts of the environment or set that will need to be animated in addition to any characters. This can also include special rigs for specific cases where a character or vehicle must perform a unique action in a particular shot.

Character Setup

When a shot has reached the lighting and composition stage in the pipeline, sometimes it is necessary for a character rig to be sent back to character setup to fix an issue that became apparent during rendering.

Order Of Rotation

A sequence of multiple rotation on different axes returns different results depending on the order. Euler rotation is a method of rotation that uses three angle values (X,Y,and Z) in addition to a rotation order to specify an object’s three-dimensional orientation.

Gimble Lock

Gimble Lock occurs when one axis of orientation is rotated in such a way that the axis is place over another axis. In this situation both axes lead to the same result when animated. This point at which a model runs out of rotations is called gimble lock. Gimble Lock is a drawback to using Euler angles to represent rotation. One method to used to avoid gimble lock is to separate the X,Y,and Z rotations into different nodes.

LocatorsA Locator is a representation of a point in 3D space. They are often used as place holder and handles that represent the translation, rotation, and scale information for another object. Locators allow character TDs to set up animation controls outside of the actual character geometry. This way animators do not have to dig through the skeleton to move specific joints in the skeleton.

Constraints

Constraints are the restriction of the position, orientation, or scale of an object. It is to create animation for an object by setting up an relationship with another object suing constraints. Constraints give animators the ability to have specific objects drive the animation for a character.

Constraints•Point Constraint – connects the translation attributes of one object to another.

•Aim Constraint – adjusts and objects rotation attributes so that they are always pointed toward another object

•Orient Constraint – connects the rotation attributes of one object to another object

•Scale Constraint – connects the scale attributes of one object to another

•Parent Constraint - connects the position(translation and rotation) attributes of one object to another object.

•Normal Constraint – aligns an objects orientation with the normal vector of another object

•Geometry Constraint – restricts an object’s pivot point to the surface of another object.

Special CasesWhen a character is being animated, special cases can occur where an animator will want another object to drive a character’s motion. Character setup artist have to consider this type of situation when setting up the character rig. Sometimes special character rigs are setup for unique motions that only occur in a handful of shots.

Set Driven Keys

Set driven keys link the attributes of one object the the attributes of another object. The relationship between objects is created to fit the specific needs of a rig. This includes situations when one control drives the movement of multiple joints like when a hand rig has the option of opening and closing the hand all at once instead of having the animator close the hand finger by finger.

Indirect Binding

Indirect binding is a situation when joints are bound to deformer like a lattice which is then attached to geometry. In the lattice case the joint animation is directly influencing the lattice and then the lattice is deforming the surface geometry. This type of binding is especially useful for creating realistic muscle movement.

Muscle Systems

A Muscle system is an advanced form of indirect binding where a skeleton controls muscle geometry which in turn influences the surface geometry of the character model. This allows the character model to have more realistic shape deformation based on the movement of underlying bones and muscles.

Blend Shapes

Blend shape deformers allow the user to change the shape of one object called the base object into the shape of another object called a target object.

Facial Animation

In addition to setting up the animation controls for body motion, character technical directors must also create facial rigs that allow the animators to convey a range of different emotions. In most cases that facial rig for a character is much more detailed that the rig setup for the rest of the body.

Facial Animation

Blend shapes deformers are often used to create facial poses for characters. Base facial poses are set up as target shapes that animators can use to blend together to create performance.

Hair

If a character requires hair, a character setup artist must set up controls for the hair or in some cases set up a dynamics system that animates the hair based on movement of the head geometry. Since hair is so complicated , special character technical directors are generally assigned the job of focusing specifically on all of the hair needs for the production.

Cloth

Similar to hair, Cloth set up is usually handled by a technical director that will focus specifically on the Cloth needs of a production. Since cloth reacts to a character’s body motion it is generally completed after animation has been approved. In order to create realistic Cloth movement, a physically based simulation must generally be performed so that the cloth geometry will react in a manner similar to actual cloth.

Cloth

In large productions, cloth simulations are tweaked down to individual folds in order to meet the director’s vision. This often means that once a shot has gone through a first pass at lighting, it must be sent to the Cloth department for tweaks specific to that shot.