Game Development Reference
In-Depth Information
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The position of the viewer depends on whether we use a directional light or a
point light
The following formula calculates the intensity of the reflected diffuse light from an
object with a diffuse material component:
I = Ip Kd (N'.L')
The parameters of the preceding formula are as follows:
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I
: Intensity
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Ip
: The intensity of the point light
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Kd
: The object's diffuse reflection coefficient; 0.0 to 1.0 for each of the R, G,
and B values
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N'
: The normalized surface normal/vertex normal
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L'
: The normalized direction to the light source
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.
: Represents the dot product of the two vectors
Specular reflection
Specular reflection is the reflection of shiny surfaces. You will see a highlight on the
object/model. A shiny metal or plastic surface has a high specular component while
chalk or carpet has a very low specular component. The following diagram shows
the effect of different light components on geometry:
