About Lighting

As we mentioned, light in the real world bounces from object to object, changing subtly and moving on. This means any given area is receiving light that is varied in intensity, energy, and direction. In Maya, light moves from a light object until it hits model geometry, where it stops. Light in Maya can acquire color from transparent objects, but other than that, it's up to you to fill in the missing behavior.

As a result, most scenes include several different lights. In general, there is a light for every major visible source (bulbs, sun, moon, fires). Because the light from these sources doesn't illuminate the far side of the objects it hits, you need to create lights to fill in the dark areas (Figure 15.3). Usually, these lights are either ambient or dimmer lights pointing in the opposite direction from your primary lights. Your scene also may have areas that you simply want to be a bit brighterthose areas require their own lights, too.

Figure 15.3. Even with very bright light, the far side of the objects remains pitch black. This unnatural look must be addressed with additional lights.

Common rigs

As you can see, lighting in Maya can become fairly complicated. To help manage this, animators use a few general lighting strategies, commonly referred to as light rigs. Building one of these layouts of lights makes a good starting point for lighting your scene:

• Three-point rig A basic setup suited for scenes with one major light source. The three-point rig consists of a Key light (the main source), a Fill light to illuminate the shadowed area, and a Rim light to highlight the edges of the object (Figure 15.4).

  Figure 15.4. The three-point light rig has a Key light as a main source, a Fill light to illuminate the dark edges, and a Rim light for highlights. In the center is the object being illuminated.

  

• Dome lighting Refers to the technique of building a sphere (or hemisphere) of many fairly dim lights. Dome lighting produces smooth, diffuse, lighting and soft shadows, but due to the number of lights, it takes a very long time to render (Figure 15.5).

  Figure 15.5. A dome light setup consisting of 60 directional lights. The lights here vary in intensity from .01 to .15.

  

• Bounce lighting Similar to a three-point rig but contains lights for the major sources. Additional dimmer lights are then set up to simulate the primary light bouncing off large surfaces. This is repeated until a satisfactory look is achieved. Bounce light is a common term for any light that is used in a similar fashion (Figure 15.6).

  Figure 15.6. A simple bounce light setup. The light originates from the key light, and the bounce is simulated by the other two lights.

  

Light warmth

By default, all light in Maya is white. In the real world, light has a faint color (except, obviously, the colors in disco lights or stained glass and so forth). To approximate real life in Maya, you can assign a very faint color to your lights as well.

Cool lights are white or light blue, and come from very high-energy sources (like the noon sun). They are best used for well-lit or hard, uncomfortable scenes such as a brightly lit laboratory. Warm lights are yellow, usually from lower energy sources like incandescent bulbs, fires, or sunrise/sunsets. You'd use warm lights for cozy, dimly lit scenes like candlelit dining rooms and country kitchens. Counterintuitively, the brighter or hotter the light source, the cooler the light appears visually. Light source temperatures are typically measured in degrees Kelvin.

The following are common light temperatures:

• 1000 K Match flame or other small fires. The light is very red.

• 2000 K Sunrise or sunset. Light is golden orange and very warm looking.

• 30005000 K Incandescent lighting. The light is light yellow. Dimmer and older incandescent bulbs tend to have more color than new ones.

• 60007000 K Daylight. Like light at high noon, this is very close to white light. Fluorescents also tend to be close to this range.

• 800010,000 K Blue sky; sunlight not at noon. Sunlight is actually a light blue color. This light looks cool indoors and severe outdoors (such as in a desert).