Early life Duff was born in
Toronto,
Ontario, Canada, and was named for his putative ancestor,
the fifth Earl of Selkirk. He grew up in Toronto and
Leaside. In 1974 he graduated from the
University of Waterloo with a
B.Math and, two years later, was awarded an M.Sc. from the
University of Toronto.
Programming career Duff worked at the
New York Institute of Technology Computer Graphics Lab and the
Mark Williams Company in
Chicago before moving to
Lucasfilm's Computer Research and Development Division. He and
Thomas Porter, another Lucasfilm employee, developed a new approach to
compositing images; their 1984 paper, "Compositing Digital Images", is "[t]he seminal work on an algebra for image compositing", according to
Keith Packard, and "
Porter-Duff compositing" is now a key technique in computer graphics. (See, for example,
XRender and Glitz.) Duff later worked for 12 years at
Bell Labs Computing Science Research Center, where he worked on computer graphics, wireless networking, and
Plan 9; in the course of his work there, he authored the well known "
rc"
shell for the
Version 10 Unix operating system. Duff worked at
Pixar Animation Studios from 1996 until his retirement in 2021. == Achievements ==