Texture-Driven Light Flickering
Sticky NoteJuly 2023 - August 2023
Brief
For the climax of Sticky Note, I wanted every light in the scene to flicker at once. The ceiling lights were light actors and the computer screens were emissive materials, so I needed one way to control both, and the flicker had to look similar on every render.
Approach
My first try panned a random noise texture across the lights, but it was too random to control. I swapped it for a set of greyscale textures that look a bit like QR codes, moved by a SteppingPannerTime node so the pattern steps along instead of sliding smoothly. Each light also offsets its time by its world-space location, which adds variation between lights without any per-light setup. The ceiling lights read the pattern through a light function and the screens through their emissive material. Both take their flicker speed from the same scalar in a Material Parameter Collection, so one value set the speed for the whole room and let us dial in the range we wanted for the final render.
