Autodesk LIGHTSCAPE, Manual

Page: 122 / 362

Using Materials 7
114
Lightscape
either the brightness of a texture map or the value of
a color (if a texture is not being used). For a color, the
average and maximum values are always the same.
For a texture map, the average and maximum values
may differ. For more information, see “Brightness”
on page 116.
It is also possible to adjust the reflectance using the
Reflectance Scale on the physics page. If the average
reflectance is out of the recommended range for the
material type selected in the template, it will be
displayed in red.
Making a Material Self-Illuminating
Surfaces do not emit light. In Lightscape, all light in
a simulation must come from luminaires or daylight.
Certain components of real luminaires frequently
appear very bright, such as the tubes of a fluorescent
light.
To make these components appear bright, give their
materials a luminance value. Luminance values are
in cd/m2. For more information on luminance units,
see Chapter 8, “Artificial Lighting.”
To make a material self-illuminating:
On the Physics panel of the Material Properties
dialog, do one of the following to set the luminance:
• Enter a value in the Luminance (glow) box
•
Enable the Pick Light option, and then click a lumi-
naire in the model to apply its luminance to the ma-
terial.
Note: The luminance value has no effect on the
actual lighting of the model; it is only a rendering
technique to make a surface appear bright.
Using a Texture Map
Use a texture map to give a material the appearance
of real-world material such as tiles, wood paneling,
or bricks. A texture map is a picture of the material
that is stored in an image file in any of the following
file formats:
File Extension: Format:
.bmp Windows native file format.
.tga Targa®, TrueVision® format.
.tif TIFF.
.rgb RGB—native Silicon Graphics®
file format.
.jpg JPEG.
.gif CompuServe Graphics Inter-
change format.
.png Portable Net Graphics.
.eps Encapsulated PostScript.