CS 284: CAGD 
Lecture #9 -- Mon 9/28, 2009.

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Rockwood Chapter 8: pp 133-151: Surfaces
Fill in: PAPER-SELECTION FORM (handout)

Warm-up Problem: How to model a bell

Possible approaches to composing a Bell shape

A good starter SLIDE file: BellShape.slf

Topic: Surface Patches

From Curves to Surfaces Patches

Triangular Surfaces Patches

We can also deal with triangular patches, but need a different interpolation scheme:
Barycentric coordinates: three numbers, but with the constraint that they must sum to 1.0.
DeCasteljau evaluation technique can also be applied to triangular patches.

Topic: Subdivision

Introduction to "General Subdivision (with modification)" Techniques

Reading Assignment:

Read the seminal paper by Catmull and Clark on subdivision surfaces

Current Homework Assignments:

Construct a Parameterized Goblet

A goblet is:
    1.  A drinking vessel, such as a glass, that has a stem and base.
    2. Archaic:  A drinking bowl without handles.
Your task is to design a curved thin (metal) surface of finite thickness that could serve as a goblet.
There are many different ways in which such a surface could be defined: Some possible approaches to composing a Bell shape also apply to forming a goblet.
For this assignment you should concentrate on using a sweep in some form and using some spline for either the cross secition or for the guide curve, or for both.
There should be from 3 to 5 parameters with wich you can change the shape of the goblet interactively without loosing continuity in the overall surface.
Let yourself be inspired by this collection of images that you get when you do a Google image search for "goblet", -- but keep your shape simple!
You may start from this SLIDE file: BellShape.slf

Create a SLIDE file with all parameters set to their preferred values.
Capture your design pictorially using the screen saver.

DUE:  Wed. 9/30/2006, 10:40am.

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