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Crawly Crypt Collection 1
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<H1><A ID="SECTION00900000000000000000">
Texturing</A>
</H1>
<P>
Textures are used to modify the appearance of an object through the
use of procedural functions. A texture may modify any surface characteristic,
such as diffuse color, reflectivity, or transparency, or it may
modify the surface normal (``bump mapping'') in order to give the
appearance of a rough surface.
<P>
Any number of textures may be associated with an object. If more than
one texture is specified, they are applied in the order given. This allows
one to compose texturing functions and create, for example
a tiled marble ground plane using the <#661#><EM>checker</EM><#661#> and <#662#><EM>marble</EM><#662#>
textures.
<P>
Textures are associated with objects by following the object specification
by a number of lines of the form:
<P>
<DIV class="CENTER">
<#664#><TT>texture</TT><#664#> <#665#><EM>name</EM><#665#> ;SPMlt;<#666#><EM>Texturing Arguments</EM><#666#>;SPMgt; [<#667#><EM>Transformations</EM><#667#>]
</DIV>
<P>
Transformations may be applied to the texture in order to, for example,
shrink or grow feature size, change the orientation of features, and
change the position of features.
<P>
Several of the texturing functions take the name of a colormap as an
argument. A colormap is 256-line ASCII file, with each line containing
three space-separated values ranging from 0 to 255. Each line gives
the red, green, and blue values for a single entry in the colormap.
<P>