His research focuses on rendering algorithms, graphics processing units, as well as scientific illustration and visualization.

in nuclear engineering in 1977,[3] continued his education there, and as a graduate student taught a new computer science course in graphics in 1981.

[4] In the 1980s he went to work at the New York Institute of Technology Computer Graphics Laboratory and at Digital Equipment Corporation under Edwin Catmull.

[10] In 2004 he shared a technical achievement award with Stephen R. Marschner and Henrik Wann Jensen, for research in simulating subsurface scattering of light in translucent materials.

[25] Hanrahan shared the 2019 ACM A.M. Turing Award with Catmull for their pioneering efforts on computer-generated imagery.