Autodesk LIGHTSCAPE, Manual

Page: 142 / 362

Artificial Lighting 8
134
Lightscape
Positioning LIDs
Each luminaire has a luminous intensity distribution
(LID) that describes how the strength of the emitted
light varies with the outgoing direction.
You set the location and orientation of the LID with
respect to the geometry of the luminaire when you
define the luminaire.
Adjusting the position of a luminaire’s LID is like
positioning the light bulb in a fixture.
▲
You can position LIDs only in the Lightscape
Preparation stage.
To specify the source type and position a LID:
1. In the Luminaires table, double-click a luminaire,
or right-click a luminaire then choose Photometrics.
The Luminaire Properties dialog appears and the
luminaire is placed in Isolate mode.
2.
In the Luminaire Properties dialog, select a source
type.
3.
If you select the Linear or Area source type, enable
Pick Panel, and click a surface in the Graphic window
to define the area or length of the LID.
4. In the Intensity group box, select a distribution
from the list. For more information, see“Defining In-
tensity Distribution” on page 137.
5.
Adjust the LID position and rotation as described
in the following sections.
6.
Click OK to update the luminaire definition.
7.
When prompted to overwrite the existing lumi-
naire, click Yes.
Using Relative or Absolute Positioning
You can position LIDs in Absolute or Relative mode.
• Use Absolute mode to enter the model coordinates
in the X, Y, and Z boxes.
• Use Relative mode to enter an explicit offset amount.
Left: LID is positioned at the bottom of the light fixture and
is aimed downward. The light beam will not be shadowed
by the geometry.
Right: LID is positioned above fixture and is aimed downward
In this position, you should make sure surfaces are non-
occluding or they will create shadows in the light beam.