# CS 284: CAGD  Lecture #19 -- Tu 10/31, 2006.

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## Feedback on Genus-L Surfaces

Make sure they are of the right symmetry and are watertight 2-manifold B-reps of a real solid object !
Run files in SLIDE and "save as SIF" -- inconsistent edge joints will be shown as red lines.
If everything is OK, the SIF file will report a single shell of the proper genus.
TURN OFF THE DOUBLE-SIDED FACES ON LINE 81 OF
GenusL_SymmDLh.slf   SO THAT CAN CHECK FACE ORIENTATIONS !

# Paper Presentations

## Oystein Doskeland: BS'92 "Minimizing the Squared Mean Curvature Integral …" Hsu et al

Focus on the experimental techniques described and on the results tabulated.
Don't get discouraged if you cannot follow all the math in the first four pages.

## Matt Brockmeyer: MC'87 "Marching Cubes ..." Lorensen and Cline

A frequently cited, classic paper in computer-aided modeling.
The basic ideas presented play a role in many related tasks.

## Prepare for your 5-minute formal Project Proposal Presentations on November 2. ("Venture Capitalist Rally" -- How to get the "gold".)

Format:
• Should last 4-5 minutes (hard 5 minute cutoff).
• Be enthusiastic, make an impact.
Content:
• The goal of the project
• The approach you will take
• The deliverables and demos resulting
• Why this is a "good" project (somewhat of a "selling" job):
• how useful it might be, or
• just how "cool" it is going to be, or
• what you hope to learn with this project ...
Presentation order, time table, and score sheet

## Finish Old Homework (Phase 1):  Build a proper genus-L surface; test it with "save as SIF"

DUE:  Thursday, November 2, noon.

## New Homework Assignment:  Put your genus-L Surface through the Surface Evolver (Phase 2)

Convert your genus-L surface piece into the format of Brakke's Surface Evolver
and experiment with it.
Make sure the Evolver accepts your description and is willing to do something useful with it.
Looking at the manual, figure out how to set the boundary conditions so that the geometry at hand is a true fundamental domain of a smooth surface.
The final goal is to find the surface of lowest bending energy while maintaining the specified genus and symmetries,
but for this phase it is sufficent to get to the point where the Evolver is willing to refine and optimize your description!

DUE:  Tuesday, November 7, noon.

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