Design Realization lecture 4

1
Design Realization lecture 4

• John Canny
• 9/4/03

2
Update

• At long last, the Maya Personal Learning CD is
  in. Good for learning Maya, annoying for
  displaying models (watermarking).
• Two readings
• Chapter on 3D shapes from Hearn and Baker
• Chapter on 3D shapes from Wucius Wong
• First assignment

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Last Time

• Basic curve creation/editing.
• Basic surface creation/editing.
• Two ways to duplicate copy and instance.
• Concepts Scene graph, transformations, history.

4
Alignment

• A basic operation on curves or surfaces to align
  endpoints or bounding curves.
• Edit Curves ? Align Curves (in modeling mode)
• Edit NURBS ? Align Surfaces ()
• Use this to join curve segments or surfaces so
  that they stay joined.
• Be careful to control which NURB moves, and how.
  Use the options in the align menu.

5
Scene graph and hierarchy

• The scene graph consists of shape nodes and
  transform nodes.
• Objects can be grouped and arranged in a
  hierarchy use hypergraph to edit
• Window ? Hypergraph
• middle mouse button drags to connect.
• Changes propagate down the chain, but not up
  and transforms are relative.
• Very important for character animation.

6
Constraints

• Constraints are relations between objects in the
  scene, in terms of their attributes.
• Alignment creates such constraints. Or they can
  be added directly with the expression editor.
• Window ? Animation Editors ? Expression Editor

7
Shape control

• For design exploration, we want to quickly
  control shape (and sometimes appearance)
  parameters to create a gallery of models.
• Maya has a tool for this called Blendshapes. Its
  based on keyframe animation but works well for
  design variation.
• (Animation) Deform ? Blend Shapes

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Todo

• Please submit critical summaries of todays
  readings by next Tuesday.
• Install and experiment with Maya following the
  assignment.
• Please return the CDs soon.
• Blog for Maya help?