Introducing Maya® 2008

Lighting Effects

In CG, you must fake certain traits of light in the real world. Using certain methods, you

can create smoky light beams, glowing lights, and lens flares. Although some of these

effects fall under the domain of rendering and shader tricks, they are best explored in the

context of lighting, as they are indeed created by light in the real world.

Volumetric Lighting

How do you create an effect such as a flashlight beam shining through fog? This lighting

effect is called volumetric lighting, and you can use it to create some stunning results,

which can sometimes be time consuming to render.

You cannot apply volumetric effects to Ambient and Directional light types. To add a

volumetric effect to any of the other types of lights, select the light, and in the Attribute

Editor under the Light Effects section, click the checkered Map button to the right of the

Light Fog attribute. This will create a new render node that will appear in the Hypershade

and Multilister windows. Once you click the Map button, the Attribute Editor will take

you to the lightFog node.

The way Maya handles volumetric lights is to attach a lightFog node to the light. The

Color and Density attributes under this node control the brightness, thickness, and color

of the fog attached to that light. Furthermore, in the light’s Attribute Editor, you can con-

trol the fog with the Fog Spread and Fog Intensity settings. Fog Intensity increases the

brightness of the fog, and Fog Spread controls how well the fog is defined within its con-

fines. For example, a Spot light with a fog will show the fog in its cone. Figure 10.39 shows

how spread affects the conical fog shape.

Figure 10.38

Smoother GI solu-

tion offers a nicer

render without

splotches.

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If you want the light fog-cast shadows to make rays of light within the fog, simply check

Use Depth Map Shadows for the light. You will have to increase the depth map Resolution

for a higher-quality image.

Figure 10.40

Light glow and lens

flare turned on for

the back light

To remove a fog effect, right-click the Light Fog label in the light’s Attribute Editor and

choose Break Connection from the shortcut menu.

Fog Spread = 0.5 Fog Spread = 2.0

Figure 10.39

Fog Spread affects

how the fog dissi-

pates to the edges of

the cone.

438 ■ chapter 10: Maya Lighting

Lens Flare

Lens flare and light glow, as illustrated in Fig-

ure 10.40, mimic the real-world effect created

when light strikes a lens or when the light source

is visible in the frame. The flare is created when

the light hits the lens at a particular angle and

causes a reflection of itself in the optics of

the lens.

To enable a light glow, under the Light Effects

section in the light’s Attribute Editor, click the

checkered Map button next to the Light Glow

attribute to create an OpticalFX node that will

appear in the Hypershade and the Multilister. The

Attribute Editor will shift focus to that new node,

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