Stephen H. Westin

Stephen H. Westin portrait

Educational Material

Education

Year	Institution	Degree
1992	Cornell University	Master of Science (Computer Graphics)
1980	University of Michigan	Bachelor of Science in Engineering (Computer Engineering)

Experience

Years	Organization	Responsibilities
May 2014-March 2018	GrammaTech, Inc.	Project: testing major security upgrade Implemented tools to track progress of testing hundreds of items. Implemented scaffolding to facilitate interactive testing before UI available. Tested ≈ 30% of items. Result: successful delivery of upgrade Also: Maintained and tested static analysis checks to enforce MISRA coding guidelines. Maintained and enhanced GUI code using wxWidgets, Python, and Javascript. Engaged in large-scale automatic and manual software testing.
November 2007-May 2014	Doron Precision Systems, Inc.	Project: new vehicle simulation software (based on OpenSceneGraph and Delta3D) carried through to deployment, replacing legacy software developed by contractor. Co-developed new vehicle dynamics model from first principles, using PAL and Bullet. Modularized for multiple axles and trailers. Developed powertrain models for Diesel and gas engines, manual and automatic transmissions. Revised several OpenGL shaders for improved quality. Participated in implementing C++ class hierarchies to represent vehicles, objects, etc. Result: Successful deployment of new software on production systems. Project: revision of geometric models for greater realism Supervised contract modeling personnel. Modeled multiple vehicles in Sketchup and 3D Studio Max. Developed several MaxScript plugins to aid modeling in 3D Studio Max. Shared in QA on revised vehicle and environment models. Result: successful deployment of new assets to positive customer feedback. Other accomplishments: Rewrote low-level serial communication with custom UI hardware. Revised old environment to support snowplow simulation.
2005-2007	Animusic LLC, Lansing, NY	Project: complete port of interactive animation software to new APIs Implemented real-time display using OpenSceneGraph. Partnered in creating custom skins for GUI using Qt toolkit. Project: deploy Pixar RenderMan software for production Installed RenderMan render farm on 13-node cluster. Verified parallel render operation. Other accomplishments: Developed custom shadowing plugin using MaxScript, eliminating render errors.
1997-2005	Cornell University Program of Computer Graphics	Managed Light Measurement Lab to support lab research. Performed measurements of illumination and surface reflection. Collaborated in research projects, co-authoring 5 publications. Collaborated in writing grant proposals. Enhanced research rendering platform (Java on cluster of 64 processors).
1992-1997	Ford Motor Company, Dearborn, MI	Project: multimillion-dollar deployment of electronic tools for creative design. Continued producing development specifications. Produced renderings and animations on a continuing basis for design evaluation. Consulted on rendering and design issues. Supplied initial technical support as needed during ramp-up. Result: successful launch of electronic design process. Project: HDTV animation for market research Supervised model creation, rendering, editing, duplication, and deployment. Provided technical expertise on rendering issues Result: ground-breaking use of HDTV video for market research, potentially saving millions in production and transportation of full-size clay models.
1987-1990	Ford-Werke AG, Köln, Germany	Project: 3-year development of CDRS CAD system for design studios. Wrote specifications for CDRS and other development Distilled requirements from stakeholders in U.S. and England, revising to reach consensus. Mediated between outside developers and Ford visual designers, translating and interpreting requirements, challenges, and limitations. Result: system readiness for deployment
1984-1987	Ford Motor Company, Dearborn, MI	Project: basic exploration of advanced digital tools and techniques for visual design. Supported experimental projects with proof-of-concept software. Visited potential vendors to evaluate possible new tools. Attended SIGGRAPH conference to see state of the art.

Publications

Papers

	Hongsong Li, Sing-Choong Foo, Kenneth E. Torrance, and Stephen H. Westin. Automated three-axis gonioreflectometer for computer graphics applications. Advanced Characterization Techniques for Optics, Semiconductors, and Nanotechnologies II, Proc. SPIE 5878, Aug. 2005.
	Stephen R. Marschner, Stephen H. Westin, Adam Arbree, and Jonathan T. Moon. Measuring and Modeling the Appearance of Finished Wood. ACM Transactions on Graphics, Proceedings of SIGGRAPH 2005.
	James A. Ferwerda, Stephen H. Westin, Randall C. Smith, and Richard Pawlicki. Effects of rendering on shape perception in automobile design. First ACM Symposium on Applied Perception in Graphics and Visualization, July 2004, 107-114.
	Stephen R. Marschner, Stephen H. Westin, Eric P. F. Lafortune, and Kenneth E. Torrance. Image-based bidirectional reflectance distribution function measurement. Applied Optics-OT, 39(16):2592--2600, June 2000.
	Stephen R. Marschner, Stephen H. Westin, Eric P. F. Lafortune, Kenneth E. Torrance, and Donald P. Greenberg. Image-based brdf measurement including human skin. In Eurographics Workshop on Rendering, 1999. This is a PDF file distilled from the actual PostScript^® file submitted for the conference proceedings, but one or two figures that were printed in black and white are color here.
	Stephen H. Westin, James R. Arvo, and Kenneth E. Torrance. Predicting reflectance functions from complex surfaces. Computer Graphics (SIGGRAPH '92 Proceedings), 26:255--264, July 1992. This is a modified version of the PostScript^® file used to make the camera-ready copy. I had to insert the images by hand, so cropping and alignment may be a bit different from the SIGGRAPH proceedings. Microgeometry for various surfaces and images used in the paper are also available.
	François X. Sillion, James R. Arvo, Stephen H. Westin, and Donald P. Greenberg. A global illumination solution for general reflectance distributions. Computer Graphics (SIGGRAPH '91 Proceedings), 25:187--196, July 1991.

Technical reports

	Stephen H. Westin, Hongsong Li, and Kenneth E. Torrance. A comparison of four brdf models. Technical report PCG-04-02, Program of Computer Graphics, Cornell University, April 2004.
	Stephen H. Westin, Hongsong Li, and Kenneth E. Torrance. A field guide to brdf models. Technical report PCG-04-01, Program of Computer Graphics, Cornell University, Jan 2004.
	Stephen R. Marschner, Eric P. F. Lafortune, Stephen H. Westin, , Kenneth E. Torrance, and Donald P. Greenberg. Image-based brdf measurement. Technical report PCG-99-1, Program of Computer Graphics, Cornell University, Jan 1999.
	Stephen R. Marschner, Stephen H. Westin, Eric P. F. Lafortune, Kenneth E. Torrance, and Donald P. Greenberg. Reflectance measurements of human skin. Technical report PCG-99-2, Program of Computer Graphics, Cornell University, Jan 1999.

Master's Thesis

Full text of thesis (PDF) This file is about 1.9MB and contains all the figures.

Educational Material:

Torrance-Sparrow
	K. E. Torrance and E. M. Sparrow. Theory for Off-Specular Reflection from Rough Surfaces. Journal of the Optical Society of America, vol. 57, no. 9, pp. 1105-1114, 1967. I scanned this into a PDF file (0.9MB).
He-Torrance BRDF Implementation
	Xiao D. He, Kenneth E. Torrance, Francois X. Sillion, and Donald P. Greenberg. A comprehensive physical model for light reflection. Computer Graphics (SIGGRAPH '91 Proceedings), 25(4):175--186, July 1991. Liang Peng and I implemented the model in C++ and verified against the original C implementation of the 1991 paper.
Fresnel Reflectance
	About Fresnel Reflectance, a short sermon on what it is and why you probably want to use it.
Gamma Correction
	I have written a brief practical explanation of monitor gamma correction, including how to find out the correction for your display.
Kubelka-Munk
	I have translated the paper Ein Beitrag zur Optik der Farbanstriche, by Paul Kubelka and Franz Munk, in Zeitschrift für Technishen Physik 12(112). Get the Acrobat PDF file (about 118K). This translation is gradually improving; please send me your corrections and suggestions. Updated Friday, March 12, 2004. Since posting this translation on the Web, I was contacted by Paul Kubelka’s son Werner, who lives in Brazil. He graciously sent me an autobiographical sketch that his father wrote, apparently in the 1940s.
Lafortune BRDF Representation
	I have written a simple RenderMan shader to implement the BRDF representation presented in Non-linear approximation of reflectance functions, by Lafortune et al. at SIGGRAPH 97. A sample RIB file showing its application to modeling human skin from measured data, compared with Matt Pharr's quick hack, is here. The resulting image from BMRT is here.

Other stuff

Art work
	From time to time, I have dabbled in drawing, both with pencil and with pen and ink. Here are a few of my drawings.
Lens register list
	Willem-Jan Markerink compiled an extensive list of registers (flange-to-film distances) for many cameras. The list has unfortunately vanished from the Web, but I have made a nicely-formatted version of his list, with some additions and corrections. I also have sorted the list by flange distance to make it easier to see which adaptations might be feasible.
Leica Order Numbers
	I have compiled a list of Leica 5-digit order numbers from sources on the Web.
Camera resolution test chart
	In 2000, the International Standards Organization adopted ISO Standard 12233: Photography -- Electronic still-picture cameras -- Resolution measurements for the measurement of camera resolution. The procedure requires a standard test target, which I have converted to a vector format so you can print your own. In 2014 and again in 2017, ISO revised the standard, and replaced this chart with several new ones which aren't available here.
Sigma SA lens mount vs. Pentax K
	Sigma SLR cameras use a unique lens mount that seems to be derived from the Pentax K bayonet mount. I have compared the two and offer a drawing with the results here. NOTE: this is an SVG document, so you may need to download a browser plugin to display it. The link to do so is on the page.
Windows Character Codes
	After years of mystification of how to generate special characters in Windows operating systems, I think I have learned something about Windows character codes.

Stephen H. Westin westin@earthlink.net

Last modified: Tue Jun 19 14:59:01 EDT 2018

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