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Next: 23.2.2 Spotlight Effect Up: 23.2 Lighting Equations Previous: 23.2 Lighting Equations

23.2.1 Attenuation Factor

The attenuation factor is defined to be:

\begin{displaymath}\hbox{attenuation factor} \; = {1 \over {{k_{c}} + {k_{l}d} + {k_{q}d^2}}}\end{displaymath}

where
d = distance between the light's position and the vertex
kc = GL_CONSTANT_ATTENUATION
kl = GL_LINEAR_ATTENUATION
kq = GL_QUADRATIC_ATTENUATION
If the light is directional, the attenuation factor is 1.


David Blythe
1999-08-06