CS 348C Project Proposal

The project proposal is a 1-2 page document that describes the intended area of a student project, summarizes relevant published work, and suggests possibilities for the concrete goal of the project.

Content

Intended area

Students must select an area related to geometric modeling and/or modeling of natural phenomena and processes. Different teams may work on the same area; however, the concrete goals of their projects have to be different. The topics list contains several suggestions on possible areas that a project may investigate. Also, the staff of Pacific Data Images has made the following suggestions:

• Meltdown; crumbling down objects.
• Earthquakes.
• Rain and snow, with an emphasis on controlling their flow.
• Constrained particle systems, such as water flowing out of a nozzle and going down a sink.
• Behavior-guided animal movement, such as flocking and herding.
• Modeling skin and ageing.
• Light shafts and rainbows, and any other subtle natural tricks of light.
• Formation and destruction of galaxies.
• Seasonal variation of trees and forests.

Although by no means they are required to do so, most students pick a topic related to the papers they researched for their in-class presentations.

Relevant work

Students must reference published work which relates to the concrete goal of their project. References outside the intended area, but relevant to the concrete goal, are highly desirable. In addition to merely listing bibliographical references, students must append a short (up to 10 lines) content summary to each referenced item.

Concrete goal

Students must propose a concrete focus of study within the intended area. For example, the students may opt to

• implement and/or optimize a particular algorithm,
• attempt to solve a specific problem,
• compare and combine two published models,
• design and implement a new modeling technique, or
• craft a new, friendly user interface to an existing modeling primitive.

The students are encouraged to read carefully the "future work" sections of relevant published work for ideas. Also, it's a good idea to contact the authors of relevant papers and ask them if they have any particular projects to suggest.

Outline of sample proposal

[ This is just an outline. A full-length proposal should have a similar structure, but the students should elaborate more on their ideas. ]

Intended area

We would like investigate the modeling of plants.

Relevant work

[ Four sample references are shown; a full-length proposal should reflect a more extensive literature search. ]

• Prusinkiewicz, Przemyslaw, and Aristid Lindenmayer. The Algorithmic Beauty of Plants. New York: Springer, 1990. The authors present a variety of techniques for modeling the structure of plants. The basic technique they use is called L-systems, and is akin to grammars used by parsers.
• Prusinkiewicz, Przemyslaw, Mark S. Hammel, and Eric Mjolsness. Animation of Plant Development. Proceedings of SIGGRAPH '93: 351-360. This paper extends basic L-systems, which can only develop structure in discrete steps, to dL-systems (differential L-systems), which can encode the continuous growth of plants. The new formalism uses (1) grammars and rewriting rules to model discrete transitions in a plant's growth, and (2) differential equations to model the gradual changes a plant undergoes between discrete transitions.
• Aho, Alfred V., Ravi Sethi, and Jeffrey D. Ullman. Compilers, Principles, Techniques, and Tools. Reading, MA: Addison, 1986. This is one of the definitive textbooks in compilers. Relevant to our project is the detailed presentation of parsing techniques, esp. the discussions on efficiency issues.
• Eldén, Lars and Linde Wittmeyer-Koch. Numerical Analysis: An Introduction. San Diego: Academic P., 1990. This is one of the definitive textbooks in numerical analysis. Relevant to our project is the discussion of differential equations and solution methods, esp. issues regarding numerical stability and convergence speed.

Concrete goal

[ A full-length proposal should be more detailed than this rough sketch. Also, several alternative goals may be presented. ] We plan to implement a dL-system parser, which will improve upon the work of Prusinkiewicz in three areas:

1. We would like to design a friendly user interface to dL-systems. That is, we would like to design an easy-to-learn-and-use specification language for entering the modules of the dL-system; these include productions, differential equation, their domains, and their boundaries.
2. We would like our dL-system parser to be efficient and stable. That is, it should be able to robustly generate plants at interactive speeds so that the animator can comfortably experiment with the dL-system parameters. This way, (s)he may gain intuition on the effect individual system parameters have on the generated plants and thus quickly design desired plants.
3. We would also like to extend dL-systems by allowing the user to specify continuous growth by arbitrary procedures, rather than mere differential equations. Such an extension raises several issues including the following: what is the proper user interface to such procedures (maybe PERL scripts)? How can the parser reliably predict when and if modules get (de-)activated?

Malleability

On the one hand, this proposal is a contract. It commits the students to begin work in the proposed area and it binds the coordinator to advise the students in that area. On the other hand, it is just a proposal. There is no requirement that the students continue working in the proposed area. In fact, few students end up doing exactly what they initially propose. The students, with the approval of the coordinator, can change the area, goal, and scope of the project at any time.