Assignment description:
Animate the swing of a chain of boxes that decays over time and appears to have weight to create overlapping motion. In this animation you are visually simulating the effects of gravity.

Minimum requirements:
Build the chain out of 4 primitive cubes. Group these objects as a hierarchy by doing the following:

1. Make a Group for each cube and rename each Group.
2. Move the pivot on each Group to the top of each cube to locate the swing's rotation point.
3. Place the cubes on top of each other with Y Translate.
4. Parent cubes by making Group2 a child of Group1 and Group3 a child of Group2, etc.
5. Set key frames to animate Group1, creating BROAD motion FIRST!
6. Write an expression to add overlapping motion to other Groups (2-4)

Expression Example: Group<#>.rotateZ=Group1.rotateZ;

Introduces:

• multiple motion graphs
• tangents types in motion
• parenting and the hierarchy structure
• expressions
• placement of keys as animation progresses

Things to consider:

• add rotation to the Y axis to enhance the look of a free hanging chain
• where are keyframes placed in relationship to each other as the motion comes to a stop?

Readings:

• The Illusion of Life, Johnston and Thomas, Chapter 3, The Principles of Animation
• Timing for Animation, Whitaker and Halas, Follow-through and Overlapping, pg. 60-63
• Principles of 3D Computer Animation, O'Rourke, Hierarchical Animation, pgs. 158 - 161
• How to Animate Film Cartoons, Blair, The Wave Principle

Tutorials:

• none

Record the shape of the main action curve from the Graph Editor here, include labeling on horizontal and vertical axes:

return to ID750 Syllabus