[Figure 15] Scene color palette.

[Figure 16] Test reference scene with desk lamp and computer.

Reference and Observation
During the process of lighting a shot, observation and reference remain worthy of consideration. For the shots in this sequence, a general look for the lighting and color scheme is chosen by the team involved in the production. A color palette is produced to gain a better understanding of the range of colors that are expected once the scene is lit and rendered (see Figure 15). These color palettes are common in fully digital features, because the entire film is of 10 mapped out in terms of colors and the moods they create. The overriding color scheme has a tremendous effect on the scene’s impact on the audience. Color establishes the mood, and this scene is dominated by the blue portion of the spectrum. This tranquil coloring helps with the sleepy, late-night time frame that the shots span. By adding small amounts of the colors found in the palette to the lights, the scene takes a step toward fitting more closely with the intended vision.

The shots in this sequence received general lighting direction from the team of artist’s participating in the production. This direction calls for the scene to be lit from the corner by a desk lamp. The glow of the computer screen is also described, but no additional specifics are mentioned. The character is obviously the focus, so the task is to create a lighting scenario within the basic range provided by the color palette and maintain emphasis on the character. A test scenario is created to investigate the type of illumination a desk lamp creates and how the glow of the computer monitor adds to the lighting of a fairly dark scene. By taking photographs of a scene with a desk lamp and a computer, additional reference is provided (see Figure 16). These photographs offer valuable footage, describing how a desk lamp can provide bounced illumination for the scene, as well as the effect a glowing computer screen can have on a character’s face. This type of reference can be collected during the entire life of a shot and usually provides suggestions for improving the lighting. Each time a difference is noticed between a reference photograph and the computer graphics scene, ask the question, “What’s missing?” By identifying the specific differences between the goal and the CG scene, creating the effect becomes a much simpler task.

[Figure 17] Shot SF-02 with a partial render around the eyes created for testing.

Tests and Isolation
Once the initial lighting rig is created, additional lights are added as the shot enters the fine-tuning stage. Once the lights are in place, the render times increase and efficient testing of the entire frame becomes impractical. Test renders at this stage need to be done on smaller portions of the frame. Detail items such as the eyes, skin, cloth and hair can be evaluated with very small renders showing only a portion of the scene. A typical method involves rendering the entire scene at its final output resolution for a single representative frame. That frame is saved and multiple tests are then created of small sections within the frame. These tests are then compared with the original render, as well as other tests, to judge whether the adjustments are successful.