Image Source: kootation.com
I have a confession to make, sometimes I have little day dreams of Pixar characters like Woody and Buzz singing to the Pixar lighting artists, “Alone in the dark…But now you’ve come along, And YOUUUUU LIGHT UP MY LIFEEEEE!” I know, cheesy, but still you would have to imagine that the characters are grateful for the skill and artistry with which lighting artists do their jobs.
Lighting artists have to be part physicist and part artist. The physics comes into play with understanding how light works and reacts in different situations. Light reacts in three basic ways with the world. Light is reflected, refracted, or absorbed. When setting up digital lights, lighting artists must take into account the basics and make sure that there is refracted and reflected light being represented, as well as absorbed light. In his Efficient Cinematic Lighting DVD, Jeremy Vickery explains that the goal of a lighting artist is to portray realistic lighting without it having to be a hundred percent realistic. Using bounce lights to accurately light a room, or at least the space around your character. Shadows with falloffs also help convince the audience of the realistic lighting, and then you use the light to artistically achieve what is needed for the scene. Using light to create ambiance, set mood, and heighten drama is a large part of what lighting artists do.
Jeremy shows how you can use lights to recreate what light does naturally in the real world, bounce and carry color and spread out. With the way technology and software are evolving there are now many different options for rendering with global illumination.
Global illumination is a general name for a group of algorithms used in 3D computer graphics that are meant to add more realistic lighting to 3D scenes. Such algorithms take into account not only the light which comes directly from a light source (direct illumination), but also subsequent cases in which light rays from the same source are reflected by other surfaces in the scene, whether reflective or not (indirect illumination).
Thanks wikipedia! So there is software that will calculate the bounced light and refracted light, and you can adjust how many thousands of photons of light you want to bounce around…Physicist anyone? Now these algorithms can create very realistic lighting, but also come at a cost of render time. Global illumination rendering solutions can take much longer to render than without. Efficiency in lighting becomes vital to maintaining productivity, which is why there are also those that would argue against global illumination for a production pipeline. While global illumination is increasing in speed and efficiency with more updates, the seemingly easy setup and one click realistic lighting leaves many images with realistic lighting, but no artistic touch.
Just because GPUs are helping to reduce render time, and global illumination is becoming faster, does not mean that the artistic side of lighting should be ignored. In fact the technological improvements should do the opposite and free artists to be able to go through more lighting iterations to pick out which light setup is the right one. Efficiency is an important part of a rendering pipeline, and lighting is a major part in determining render times. Large companies like Pixar don’t use global illumination unless they deem it necessary, and Jeremy Vickery mentions that while that could change in the future it hasn’t for now. Light it up!