CS 285: SOLID MODELING

Lecture #3 -- Tue, Sep. 4, 2007.

Warm-up Thinking Exercise:

 How do you capture the main idea of this sculpture ?   How do you generalize this paradigm ?

The Central Steps in the Design/Modeling/Prototyping Process

• Step #3: Transformation into a CAD model  (--> something a computer can read)
  How do you get those ideas into the computer?
  ==> Discussion of homework assignment.
• Step #4: Implementation Concerns  (--> something a computer can "understand")
  What do you need to do to turn that data into a solid model?

First Homework Assignment: (possible clarifications ?)

A#1: Planning the Construction of a Solid Model

Procedural, Parameterized Modeling with SLIDE

Example: "Viae Globi"

Basic Concepts about Sweeps

• Need a sweep curve (typically in 2D or 3D space)
  
• Need a cross section (may turn and vary as it travels along sweep curve)
• Frenet frame (to facilitate the issues of orientation when applying the cross section to a sweep curve)
  

Introduction to SLIDE

• SLIDE originated as a toy rendering system for CS 184
• SLIDE lies between Mathematica / Matlab and traditional CAD tools (Solidworks, Autocad)
• It describes boundary representations (B-reps)
• Most numerical values can be substituted by expressions that are evaluated in each rendered frame.
• Offers interactive fine tuning of critical parameters via sliders
• It builds on OpenGl (for rendering) and Tcl (user interface, expression parsing)
• Main drawbacks:
• Not a properly maintained system.
• Tcl is a pain during the debugging process!