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
lighting effects 437
83564c10.qxd 10/23/07 2:26 PM Page 437
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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