Too expensive to use on Spider-Man, global illumination has advanced so much in a few years that Sony Pictures Imageworks found it a viable solution on Spider-Man 2.
- Filmmakers are always raising the bar on what vfx artists need to create, especially in the area of photorealism. Janet Hetherington of VFxWorld.com chats with professionals about the newest mandatory effect: global illumination. From Wayne Tower in Batman Begins, to a magically controlled spider in Harry Potter and the Goblet of Fire, to an array of imaginative environments in King Kong, Revenge of the Sith and the upcoming Monster House, vfx pros are using global illumination to trip the light fantastic and make the unreal look convincingly real. Global illumination algorithms used in 3D computer graphics take into account both direct illumination (the light which has taken a path directly from a light source), and the indirect illumination (the light that has undergone reflection from other surfaces in the world), when considering light falling on a surface. "Global illumination has made a huge difference to the approach to creating 3D lighting effects," says Paul Franklin, visual effects supervisor and head of 3D at London-based Double Negative (Batman Begins, Harry Potter and the Goblet of Fire and Doom). "The technique has made a major contribution to the ever-increasing realism of 3D environments seen in films today." Franklin adds that before the advent of practicable global illumination, most 3D environmental lighting was produced through a series of elaborate "cheats," which would work for a few hero shot angles, but which would generally break down if the camera moved around too much. "Global illumination's use of optically and physically correct simulation helps to produce a continuous lighting environment that behaves in a consistent and naturalistic way," he suggests. "We started using GI techniques - mainly ambient occlusion and ambient reflection - at the beginning of Spider-Man 2, and the difference that made in our environments compared to Spider-Man is clearly visible. Ever since then we have kept refining those techniques," comments Peter Nofz, digital vfx supervisor, Sony Pictures Imageworks.
"The challenge is always balancing realism.............Read full article!!