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1190 Chapter 15: Lights and Cameras
Thesearethelightshadersprovidedwith3dsMax:
Shader Library
Light Infinite base
Light Point base
Light Spot base
Photon Emitter Shader—Click the button to display
a
Material/Map Browser (page 2–1256) and select
a shader. Once you have selected a shader, its name
appears on the button.
Wa rn in g : No photon emitter shaders are provided with
3dsMax. Thisoptionisforuserswhohaveaccessto
light map shaders via other shader libraries or custom
shader code.
Additi onal R ollout s f or
Standard Lights
Intensity/Color/Attenuation
Pa r a met er s
Create panel > Lights > Create a Standard light. >
Attenuation Parameters rollout
Attenuation settings cause distant objects to be dimmer.
The Intensity/Color/Attenuation rollout allows
you to set the color and intensity of your light. You
can also define the attenuation of your light.
Attenuation (page 3–1006) is the effect of light
diminishingoverdistance.In3dsMax,youcan
set attenuation va lues explicitly. The effect s can
vary from real-world lights, giving you more direct
cont rol over how lights fade in or fade out.
Note: With no attenuation, an object can
paradoxicallyappeartogrowbrighterasitmoves
away from the light source. This is because the
angle of incidence more closely approaches 0
degrees for more of the object’s faces.
Twosetsofvaluescontrolattenuationforobjects.
TheFarattenuationvaluesetsthedistanceatwhich
the light drops off to zero. The Near attenuation
value sets the distance at which t he light "fades
in." Both these cont rols a re turned on and off by a
toggle called Use.
When Use is set for far attenuation, the light at
its source uses the value specified by its color and
multiplier controls. It remains at this value from
thesourcetothedistancespecifiedbyStart,then
itsvaluedropsofftozeroatthedistancespecified
by End.
Adding attenuation to a scene
When Use is set for Near attenuation, the light
valueremainsatzerouptothedistancespecified
by Start. From Start to the distance specified by
End, its value increases. Beyond End, the light
remainsatthevaluespecifiedbythecolorand
multiplier controls, unless far attenuation is also
active.
You can’t set the Near and Far attenuation
distances so they overlap.