Intuitive Rigging

1
Intuitive Rigging

• Exploring and refining the process of 3D
  character rigging by building an advanced 3D
  character animation rig is the essential element
  of 3D character animation.

2
Introduction

• Rigging is a process requires a 3d character
  rigger to provide controls over a 3d character
  model for 3d character animator
• Early traditional rigging were only apply to
  physical puppets
• Proto character rigging techniques for puppets
• String puppets
• Puppets on stick
• Shadow puppets
• Hand puppets

3
Traditional Technique

• Comparison of the traditional technique (i.e.
  string and wooden joints)
• Quite efficient- managed to bring drama to the
  audience in a miniscule sense
• Supported by the imagination of the audience and
  good story telling skills of the puppet master
• Pros
• Simple yet effective method
• Crude material but extremely fine craftsmanship
• Cons
• Limited movement
• Cannot portray complex movement and expressions,
• Plain give away with the supportive structure and
  controllers

4
Stop-motion Technique

• The invention of film gave rise to the invention
  of animated effects, such as stop-motion
• King Kong, 1933, pushed the stop-motion technique
  to a new high. Pioneered by Willis O'Brien
• Ray Harryhausen continued to utilize stop-motion
  technique in many films i.e. The 7th Voyage of
  Sinbad, Jason and the Argonauts

5
Pre-rigging Modeling

• The methodology of good 3d modeling- defining
  contour and topology
• Modeling methods NURBS(patch modeling), polygon
  and subdivision
• Different modeling techniques require slightly
  different binding approach

6
Rigging The principles

• Visually recognizable control selections
• Easy to select
• Unbreakable
• Scripting and expression
• Basic deformation controls(procedurally
  implemented to the rig)

7
Intuitive Rig

• Controls are at the hand of the animator
• The 3d character can be easily selected and
  manipulated
• Customizable animation attributes to provide
  wider range of movement and poses
• Several levels of controls
• locomotion, facial expression and secondary
  motion
• The more flexible the rig is, the more successful
  the animation will be

8
3D Joints

• Most fundamental element in rigging
• Methodology of muscular system, the mechanism
  that moves us
• Joints method is used in 3d rigging to facilitate
  the controls of animation
• More viable approach, less computational needs

9
Network of Joints

• Breaking down into different division of the
  joint network
• Various region of the body require different
  rigging techniques
• More flexible deformation on the character
  require more joints

10
Representational Approach

• Implementation of the selectable controllers
• Strategic joints are linked by visually
  recognizable shapes
• Whole network is divided and influence by
  different controllers
• Expression added to drive the joints
• Additional expression for muscular deformation
• Procedures are written for repetitive processes
  (recursive process)
• Basic dynamic control is implemented
• i.e. Jims semi-soft body paradigm

11
Direct Selection Approach

• Implementing the low-res model itself for
  selectable controllers
• The character model is detached into different
  region of the body
• Joints are parented to the correspondent body
  parts
• So far only FK technique can be used with this
  technique
• Consideration of having IK and FK switch
• Expression and real-time basic dynamic are
  implemented

12
Character Binding

• Process of assigning each and every single
  vertices or CVs to the joint system
• Hand tweaking and weight painting are required
• Deformational shapes are added before the binding
• Other deformational influences will be employed
  for better deformation
• Much more complex simulation are passing down to
  dynamics TDs (I.e. hair and cloth)
• The bound character is vigorously tested

13
Conclusion

• Shadow puppet as a metaphor for intuitive
  character rigging
• Character TDs will have to go through many
  phrases of testing of the rig
• These days its viable to employ complex
  real-time dynamic with much more powerful
  machines
• An intuitive and efficient rig will ultimately
  smoothen the process of animation
• Real-time character dynamic will provide a better
  feedback for the animator
• Will further explore a hybrid rig which implement
  both direct and representational selection
  rigging approach