2009

Table Of Contents
3 Set Dropoff to 10.
This attribute sets how much the light intensity diminishes from the
center of the circular region out to the edge. Finding the right value is a
matter of experimentation. When you increase the Dropoff, the lights
intensity diminishes, so you need to increase the Intensity. For example,
increase the Intensity to 1.6. Rendering creates this result:
To mimic the way a light sources intensity naturally decreases with
distance, you might want to select a Decay Rate to diminish the lights
intensity. The Linear setting diminishes light with the least abruptness,
Quadratic with the most abruptness. Cubic is between the two other
settings.
The default setting is No Decay, which means the light remains at full
intensity regardless of distance. If you use a setting other than No Decay,
you likely will need to increase the Intensity. For this lesson, leave the
Decay Rate set to No Decay.
4 Set the Penumbra Angle to 10.
This attribute controls the softness along the edge of the area of
illumination provided by the light. Again, finding the right value is a
matter of experimentation. You can also use negative numbers to fade
Editing light attributes | 431