Autodesk 256B1-05A761-1301 - AutoCAD Revit Structure Suite 2010, Руководство пользователя

Страница: 1231 / 1638

Description Parameter
TIP In general, Luminous Flux provides more accurate lighting in rendered images than
Wattage and Efficacy.
The light energy per unit of time emitted by a point source in a particular direction. Lu-
minous intensity is used to describe the directional distribution of a light source, that is, Luminous Intensity
to specify how the luminous intensity of a light source varies as a function of the outgoing
direction. The Candela (cd) is the unit of luminous intensity.
The luminous flux incident on a surface of unit area. Illuminance measures how much
energy has fallen on a surface. This quantity is useful for describing the level of illumination Illuminance
incident on a surface without making the measurement dependent on the size of the
surface itself. The lux (lx) is the International System (SI) unit of illuminance. The American
System (AS) unit for illuminance is the footcandle (fc), equivalent to 1 lumen per square
foot.
Illuminance is a function of the distance from the light source. Specify the distance at
which the illuminance is measured. At a distance of
Defining the Initial Color
When defining a lighting fixture, you can specify the initial color of its light source. The initial color is the
color appearance of the emitted light, before it is affected by color filters or environmental factors.
To define the initial color of a light source
1 Open the lighting fixture family.
2 Click Family Properties panel
➤
Types.
3 For Name, select the family type to modify.
4 Scroll down the list to locate the Initial Color parameter, and click in its Value column.
5 In the Initial Color dialog, specify values for the parameters.
See Initial Color Parameters on page 1189.
6 Click OK.
The Family Types dialog displays the new Initial Color value.
7 Click OK.
8 Save changes to the lighting fixture family.
Initial Color Parameters
When defining the Initial Color for the light source of a lighting fixture, define the parameters as follows.
Description Parameter
Select a value from the list, or select Custom to specify a Color Temperature. Color Preset
The color appearance of the light produced by the light source, expressed on the Kelvin
scale (K). Color Temperature
Creating and Modifying Lighting Fixtures | 1189