Project 4 : Character Modeling

Reading:	Chapter 9, Section 10.6 (Kerlow)
	John Lasseter's SIGGRAPH '87 paper: Principles of Traditional Animation Applied to 3D Computer Animation

Once again, new groups have been created. Unlike the past few projects, this project does not build on models from previous assignments. It does, however, build on your experience in creating and shading models.

An important, early decision you must make is whether or not to use skeletons in the construction of your character. The choice you make will affect how the character will be animated. Skeletons allow you to use inverse kinematics. For more on this, read the relevant parts in Learning Alias.

The SBD (Scene Block Diagram) window in Alias will become increasingly important from here on out. Make sure you are comfortable using it to access and manipulate parts of scenes and models.

To learn about the tools for building and animating characters, read Learning Alias:

• Lesson 16
• Character Animation (pp. 331-340)
• Lesson 19
• Lesson 18 (as needed)
• Lesson 20 (as needed)
• Lesson 17 (as needed)
• Lesson 21 (as needed).

1. As a group, think up an articulated character, i.e., one that is built from a collection of rigid pieces. Design and plan carefully. Some characters built now may very well figure in the final animation. To help organize and record your plans, make a model sheet for your character. This document should include the following:
   • Sketches of the character in a neutral pose (front, back, side, and/or 3/4 views as appropriate), in various typical poses, and in a few extreme poses.
   • A written description of the personality of the character.
   • Sketches of the construction of the character indicating how pieces are grouped, what pieces and groups are named in the SBD, and the articulation parameters and constraints that control the model.

   While creating this document may seem like a lot of extra work, it will definitely pay off later as people who were uninvolved in the modeling of the character attempt to animate it. It will also facilitate communication within your group as you do the modeling. The model sheet is not an optional part of this assignment. Hand in a copy in class on Friday.

2. Build the character. Pose it in the various sketched poses of the model sheet. Make a note of the parameter settings used to achieve each pose, and add that information to your model sheet. This will come in handy next week when you will animate the character.

3. Block out a simple action, that shows your character in a particular mood or reacting to a particular situation. To do this, create a keyframe pose for the beginning and the end of the action, and possibly one for the middle if needed. Render the resulting animation, letting Alias interpolate the motion its own way for now. This default motion will be a standin for the real animation, which is next week's project. For now, focus on conveying your character's personality through the key poses. Make up the story that leads up to the action. If we have time in the critique we will look at each action twice: first without hearing the story context and then again after.

   Cliche example: sitting sad
   

   • background context: Character just realized that she forgot all about and thus completely missed Friday night's showing of Citizen Kane.
   • visual cues: initial shock and dismay, followed by profound sadness -- drooping shoulders, arched spine, elbows bent to help support heavy head, etc.

   Another example: scoring soccer goal
   

   • background context: Character is kicking ball for the final score in the championship game.
   • visual cues: prepared to kick, intense concentration, maybe anxiety, followed by kick, followed by relief, jubilation, etc.

1. The key here is coming up with a character that is interesting and expressive despite having entirely rigid pieces. Be creative! Think carefully about how the character moves and what the best way is to control it: what's the "root", is it controlled by forward or inverse kinematics, etc. All this information should be included in the model sheet.

2. Here, the purpose is to implement the design of your character. The model should be built and shaded with the appropriate degree of detail: that is, as much as is necessary to make the character look good. If you can use model pieces built for a previous project, that's fine. Be prepared, however, to return to the drawing board if the model does not animate easily or well.

3. Put yourself in your character's shoes. Act it out. This is all about body language. Your goal is to convey personality and emotion through the shapes of the key poses themselves. But don't worry about fine-tuning the actual motion. That's next week's project.

Bring your model sheet to class on Friday. Bring the final, annotated model sheet to the critique on Monday. Before the critique, create a group directory in the critique/character directory and place there the following:

1. README file with who-did-what information.
2. Rendered images showing neutral, natural, and extreme poses. Images should be in .rgb format.
3. A flipbook animation of an expressive action or reaction.
4. Any other interesting or informative animations or images you want to turn in. Please explain what they are in the README file.