Monsters University is the first Pixar film that used global illumination, a new lighting system introduced as part of the overhaul of the rendering system used since the first Toy Story film. In the planning stage of the film, director of photography, Jean-Claude Kalache, asked "What if we made these lights just work?" Before the new system, artists had to build reflections and shadows manually, which became increasingly complex as the models and the setups became more technologically advanced. The new lighting system uses ray tracing, a technique that imitates the behaviour of the light in the real world; this automatized the process, delivered more realism, produced soft shadows, and let the artist spend more time on models and complex scenes—some of which contained thousands of light sources.^[28][29]
For research, the filmmakers visited several colleges in the U.S., including Harvard University, Stanford University, and University of Alabama, observing college architecture, student life, Greek organizations, and the teaching methods of professors and faculty.^[30][31][32] To research fraternity life, which is central to the film, many of the film's producers spent several weeks at a fraternity house.^[31]