Lighting 101

Most photographers, cinematographers, and stage-lighting designers will tell you that lighting is an art in itself. The photographic process is more sensitive than the virtual cameras you use in 3D animation, however, so you have more options than a photographer does. For example, you can create lights that don't cast shadows, objects that are not affected by a specific light, or lights that never fade in intensity. However, you can still learn some useful tips from the basics of photographic lighting.

Standard Lighting Model

Every scene you create has its own unique lighting requirements, but for standard lighting of a typical subject, photographers generally use a three-point lighting approach . This method is good for computer animators, too. These are the three points (see Figure 1.7):

• Key light A primary front light source, it's the dominant light source in a scene. It's usually set some distance to the left or right of the camera so that its shadows are apparent. In Maya, the key light is normally set to cast shadows.

• Fill light A secondary front light source used to counter the shadows cast by the key light. It's usually less bright and is often placed at the opposite side of the key light. You can determine whether the fill light casts shadows in Maya. Generally, only one or two lights should cast shadows on the same area in a scene. Too many shadows weaken the effect and slow down image calculation.

• Back light A background wash of light used to bring out the subject's back side and the backdrop. You can set Maya's back light to not create specular highlights, meaning it won't create highlights on shiny surfaces.

Figure 1.7. A three-point lighting approach.

Another light often used for 3D animation is the rim light . Like a crescent moon, the rim light is positioned to accentuate the subject's visible perimeter. A common approach is to tint the rim light, often light blue. In Maya this light can be set to illuminate only the subject so that the backdrop doesn't exhibit illumination from a tinted light. The color contrast of a tinted rim light on the subject can make it pop out from the background, particularly if the rim light is a complementary color of the background.