ME 6104 - Fundamentals of CAD

Winter 1995
 
 

Goals: To introduce fundamental technologies underlying CAD and show how they can be used to aid designing, not just geometry documentation. To provide an open classroom where students can learn by doing and relate the course material to their research and experience.

Instructor: Dr. David Rosen, 252 MARC Building, Phone: (404) 894-9668, email: david.rosen@me.gatech.edu, Office Hours: M 11:00 - 12:00, 1:30-3:00 Th and by appointment

Text: M E Mortenson, Geometric Modeling, John Wiley & Sons, 1985.

 Supplementary course notes at the Bookstore (from PPC)

References:

• G. Farin, Curves and Surfaces for Computer Aided Geometric Design, Academic Press, 1990.
• Faux & Pratt, Computational Geometry for Design and Manufacture, Horwood, 1979.

Grading:

• Homework: 40%
• Project 50%
• Proposal: 5%

• Demo: 10%
• Critical Evaluation 10%
• Final Report: 20%
• Presentation: 5%
• In-class participation & attendance: 10%

Four homework sets will be given: 3D transformations, Bezier curves, Bezier surfaces, and solid modeling. Some usage of commercial CAD systems will be required. For the project, you must prepare a proposal and a final report to turn in. Additionally, a project demonstration and in-class presentation will be required. A list of project ideas and descriptions will be forthcoming shortly. The final exam time will be used for the presentations. For those groups that do not have demonstrations, the final report will be worth 30 % of your grade.

For homework, you will need to use a mathematics package and/or write curve and surface code, then display the results using computer graphics. You are strongly encouraged to find suitable programming environments as soon as possible (Matlab, Macsyma, or similar, Spreadsheets. MathCad is not recommended).

Topics: Introduction to CAD and geometric modeling. Curves and Surfaces. Solid modeling. Variational geometry. Feature-based design. Additional topics.
 
 

Policies: Homework assignments are to be completed individually. Projects may be done in groups of 2 to 4. Homework and reports are due at the class period. You are encouraged to actively participate in class. Video students: homework and reports are due one week after posted due date/must be postmarked on the specified due date. You may work individually on projects.

Generic Syllabus for ME 6104 Fundamentals of CAD

        Subject                                         Reading

        Intro, CAD, Project Discussion                  Chap 1, Appendix C

        3-D Transformations                             Appendix C

        Curves, Parametric Space, Splines               Chap 2, 3

        Bezier and B-Spline Curves                      Chap 4, 5

        Homework 1 due (transformations)

        Surfaces, Parametric Space, Blending Functions  Chap 6, 7

        Project & Team Proposal Due

        Bezier Surfaces                                 Chap 8

        Applications of Curves and Surfaces in design

        Solid Modeling Fundamentals                     Chap 10

        Homework 2 due (Bezier curves) 

        Plane Models

        Solid Model Construction                        Chap 11

        Boundary Representation

        Homework 3 due (Bezier surfaces)

        Boolean Operations 

        Parametric and Variational Modeling             Light & Gossard 

        Feature-Based Design Handouts

        Applications of Geometric Modeling in Manufacturing     Handouts

        Homework 4 due (Solid Modeling)

        CAD-to-Rapid Prototyping 

        (Work on Projects)

        In-Class project presentations.  Final report due.  (Scheduled final exam)

General Guidelines for Reports

It is expected that your reports be of professional quality. All reports should be produced on a word processor to make the tasks of revising and correcting easier. All reports are expected to be grammatically correct and contain no spelling errors. Drawings should be produced on a computer.
 
 

Project Proposal

In this report, you will propose a project for the quarter.  Proposals are prevalent in all professional life (especially academia) and this will be an opportunity to learn how to write one.  The report should be no longer than 2 pages (single-spaced) and should be written for a technical, but not specialized, audience.  The proposal outline should be similar to:

Problem to be Addressed - concisely state what problem you propose to solve, then give a brief background on the problem.

Significance of Problem - State why your project has significance, that is, why should this problem be solved, the impact of the solution, etc.

Results & Deliverables – what tangible results should I expect from this project?   Things like final report: survey or in-depth report, computer program: what will it do, how will it be used, publishable paper, ...

Intellectual Contributions – what will you learn by working on this project?  Try to be comprehensive.  Include mundane things like learning CAD, FEA, SLA, injection molding, etc., but also include deeper intellectual things relating to the use of CAD in product realization.  Include a list of 3-4 or more “deep intellectual” learning objectives for your project.  For example, don’t just say “Learn CAD,” instead say something like “Learn how to construct good parameterization schemes for complex assemblies that allow me to generate a family of products.”

Schedule - provide a schedule of your proposed activities throughout the quarter for this project.  Include what tasks you will perform and their order (use a Gantt chart – use Word or drawing program, Microsoft Project is not necessary).
 
 

Final Report

Since this report will be worth 20 or 30 % of your grade, considerable effort should be expended writing the report. As a minimum, the report should describe the problem you are solving, provide background on the problem, document your approach with relevant mathematics, algorithms, data structures, or whatever is appropriate, then report your accomplishments. Use appendices for gory details. Finish with a discussion of your primary conclusions, the impact of your project, and directions for future work.
 
 

A suggested outline for your report is as follows:

Abstract: You are to write an abstract for your project (at most a half page). Abstracts are best described as a summary of a summary. You should briefly describe the problem, your approach, and the results. Always relate your results to your goals.

Introduction: Develop a concise problem statement for your project, then expand the statement to incorporate more detail. Provide background, state why it is important, and conduct a literature search. (Of course, if your project is a literature search, then a somewhat different structure should be used.)

Body: This may consist of several sections. Describe your approach, what you did, and the mathematical or computational aspects of your project. Be sure to identify anything that you believe is new (equations, algorithms, application of existing technique).

Results: What are your results? How did your computer program work? Did you run out of time?!? Do your computer results agree or disagree with your math or computational model? Why or why not?

Conclusions: Primary conclusions, the impact of your project, and directions for future work.

Grading Criteria for final report.

 Presentation - concise and complete

 Accomplishments - what you did; what you learned

 Overall research method
 
 

Critical Evaluation: Evaluate what you have learned in this course and present your evaluation in an essay of length no more than 2 pages. More on this later.

WRAP-UP OF ME 6175

Presentations

Presentations will be limited to 10 minutes apiece, followed by a 1 or 2 minute question/discussion period. Due to time constraints, we need to have presentations on both the last day of class, Thursday March 10, and during the final exam period, Friday March 17 (8:00-10:50).

Presentations must not get bogged down in details. State the problem you are addressing then briefly describe why it is important. If appropriate, outline your plan of action. Summarize what you did for your project and identify what is new; i.e., any new contribution, algorithm, data structure, or idea. Summarize your main results. Tell us about any difficulties that you encountered during your project - Why is this a tough problem to solve? Finish up with conclusions.

 Following the rule-of-thumb of 1 minute for each slide, you have to fit all of this material on 9 or 10 slides. Don't overwhelm slides with too much text or detail. Use figures as much as possible. If appropriate, introduce an example early in your presentation and use this example throughout so the audience can see the connections to the different aspects of your project.

Demonstrations

If you have working code, or plan to have working code, please set up a time with me to demonstrate your project. This time can be during finals week. Remember that the demo is 10% of your grade; without a demo, your final report is worth an extra 10%.

Critical Evaluation (of yourself)

The Critical Evaluation will count for 10% of your course grade. Throughout this course, you have encountered different geometric modeling, representation, and creation methods, including some state-of-the-art research methods. Here is one opportunity to bring all of this material together into a cohesive whole and put it into the context of engineering applications of CAD and geometric modeling. In this assignment, your job is to evaluate what you have learned in this course and present your evaluation in an essay of length no more than 2 single-spaced pages. As a guide, answer the questions below in your evaluation. Note: you will not necessarily get points for flattering or criticizing the instructor or the course. You will be graded on the clarity with which you communicate your thoughts and the number and quality of the "learning" points that you make in your essay. What is a "learning" point? An observation followed by an analysis of that observation, finishing with a conclusion.

1. What were your goals for this course at first? What are your goals now? Comment on the changes in your goals and how they affect your approach to solving design problems using CAD. Have you achieved your goals?
2. What are the skills (abilities, proficiencies, expertise) you picked up / refined as a result of taking this course and doing the exercises? What have you learned (intellectual) as a result of taking the course, doing the exercises, and working on your project?
3. Reflect on the stated goals of the course. What are the "fundamentals" of CAD? What have you learned about geometric modeling, human-computer interaction, and information modeling relative to engineering design?
4. What is geometric modeling? What do you see as the role of geometric models, geometric modeling, and CAD in engineering design and product development? How does your project fit into this framework?
5. What is the role of CAD in engineering product development process? What should it be?