Autodesk LIGHTSCAPE, Manual

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Artificial Lighting 8
138
Lightscape
oblique angles. Diffuse distribution is valid for Linear
and Area source types.
To define a diffuse light distribution:
1.
In the Luminaire Properties dialog, select Linear
or Area from the Source Type list.
2.
Select Diffuse from the Distribution list.
3.
If necessary, adjust the Intensity Magnitude.
4.
Click Apply to update the luminaire definition.
Spot
Select this distribution type to define a spotlight
distribution with an accompanied beam and field
angle. The beam angle is the angle at which the inten-
sity of the light is 50 percent of the maximum intensity
at the center of the beam.
Visually, the beam represents the visible diameter
(hot spot) of the spotlight on a surface. The field angle
represents the angle where the light is abruptly cut off.
A spotlight where the field is much greater than the
beam has a soft-edged effect (flood light).
Spot distribution is valid only for Point source types.
To define a spotlight distribution:
1.
In the Luminaire Properties dialog, select Point
from the Source Type list.
2.
Select Spot from the Distribution list.
3.
If necessary, adjust the Intensity Magnitude,
Beam Angle, and Field Angle.
Note: Because the beam angle has to be smaller
than the field angle, you should enter the field angle
first followed by the beam angle.
4.
Click Apply to update the luminaire definition.
Photometric Web
Select this distribution type to use a photometric web
definition to distribute the light. A photometric web is
a 3D representation of the LID of a custom light
source.
You can define your own photometric webs or import
manufacturer or customized IES files in your models
and associate them with luminaires.
Photometric webs are valid for all source types.
For more information on photometric webs, see
Chapter 9, “Photometrics.”
Orthographic view of a
Linear source type set to
Diffuse distribution.
Orthographic view of a Point
source type set to Spot
distribution. The Beam Angle is
30 and the Field Angle is 45.
Orthographic view of a
Point source type with
a custom Photometric
Web distribution.