CSE391 Procedural Generation of 3D Objects

Dept. Computer Science
SUNY Stony Brook

CSE391 Special Topics:
Solid Modeling
Fall, 2004

Prof. George W. Hart: Office: 1421 Computer Science, Phone: (631) 632-8959, Email: george At cs DOT sunysb DOT edu

Office hours: Tuesday and Thursday, 1:15 - 2:15, and by appointment.

Class room and time: Room CS 2129, Tuesday and Thursday 9:50-11:10AM.

Class web page: http://www.cs.sunysb.edu/~george/CSE391.htm

Announcements: No class thursday Sept 16 due to university holiday. Thursday Sept. 23, in class, we will take a tour of the SLS machine on campus in the Engineering building---meet at the regular classroom and we will depart from there.

There was an error on Solar in stating that you needed to take Graphics (CSE328) as a pre-requisite for this course. You may take this course without taking Graphics. If you avoided registering because you thought you didn't have the pre-requisites, come see me and I'll let you in. Tell your friends too!

Homeworks:

HW#0: Look at last year's projects to get a sense of what you can do in this class. Come to the first class with some ideas of what you might like to make.
HW #1: Read the Castle Island RP tutorial and from there, the descriptions of each technology.
HW #2: Find an environment for using Java3D and JBuilder. You should be able to install, run, and edit this Java 3D torus demo. You have an account in the Transaction Lab or you can install Java3D on your own computer.
HW #3: Modify the torus demo to make an open-faced torus, meaning it is hollow with trapezoidal openings, as shown below, using the modifications discussed in class. Be sure there are solid struts, bounded on all sides. Two additional parameters would be natural, allowing you to control the size of the opening and the thickness of the shell.

HW #4: Read about the STL file format. Consider its strengths and weaknesses and how it could be improved. This paper has some good ideas. Add STL output (either binary or ascii) to your project/viewer. You can test if the output is legal STL with the excellent freeware Solid Viewer by Marcam.

Projects page: Students' productions from this class in 2003.

Material: This special topics course will cover aspects of procedural modeling and automated fabrication for complex three-dimensional objects, including: Survey of the state of the art in rapid prototyping (RP) technologies to understand their strengths and limitations. A tour/demo of the two RP machines on campus. Design problems requiring 3D thinking and visualization, including symmetry, fractal, statistical, and other regularities. Criteria for when procedural generation is the right tool to solve a problem. Representation and modeling techniques suitable for structured objects, e.g., polyhedra, splines, L-systems, etc. Mathematical techniques for 3D manipulation. Available software tools. Current 3D file formats and concepts for future formats.

Students teams will complete software projects that produce 3D object description files which we will fabricate on a rapid prototyping machine. This includes the steps of:

3D conception and design,
algorithm and data structure conception and design,
implementation to create a computer model suitable for virtual reality display,
generation of 3D object description file, and
physical production on RP machine.

Prerequisites: AMS 210 (Linear Algebra) or its equivalent.

Text: There is no textbook which covers this material. Papers will be assigned for reading and discussed in class. Most will be easily available on web pages.

Class Format: This is a project/seminar course. An important part of the course (and grade) is participating in the class discussions. You should come to all classes. We will discuss the student projects and the spatial and software design problems that they suggest. Students will present their projects to each other both in the design phase and after completion. We will also do a few 3D design activities. Reading assignments and informal homeworks will be assigned weekly and discussed in class.

Projects: There will be two software projects required for this course. Students will work in pairs, with different partners for each project. Each project requires you to create, demo, document, and present to the class working software that produces a family of novel 3D objects. An .STL file generated by your program will be used to drive the RP machine to create a new unique physical object (that you get to keep). The .STL file is due two weeks before your final write-up is due, so we have time to schedule it on the RP machine and you can discuss it and include a photo of it in your paper. The details of each project, their due dates, lab space, and other details will be disucssed in class. You may use C/C++ and OpenGL, or Java and Java3D, or other languages and environments as you prefer.

Rapid Prototyping Resources: Stony Brook University has a Stratasys 3000 and a DTM Sinterstation 2500 Plus. The Stratasys 3000 is an FDM machine which creates in ABS plastic and also produces a water soluble support structure. The DTM 2500Plus is an SLS machine that uses a self-supporting powder. (The DTM company is now part of 3D Systems.) We will use the Stratasys 3000 FDM machine to make parts in this class.

Grading: Project 1, due at mid-semester (30%); Project 2, due at end of semester (50%); Class participation (20%).

Background: For general information about RP, see the Utah RP site or the Castle Island RP site. For examples of objects I have designed by procedural generation and then fabricated by rapid prototyping, follow these links. But your projects may be very different in style:

Limited enrollment: The RP machine we will use has limited capability, so we can only create real objects for a limited number of projects.

Disabilities: If you have a physical, psychological, medical or learning disability that may impact on your ability to carry out assigned course work, you may contact the staff in the Disabled Student Services office (DSS) in the ECC building, or call them at 632-6748v/TDD. DSS will review your concerns and determine with you what accommodations are necessary and appropriate. All information and documentation of disability are confidential.