#!F-adobe-helvetica-medium-r-normal--18*
#!N 
#!N  #!Rcolcom Colors, Front Colors, 
and Back Colors Components #!N #!N #!N The "colors," "front colors," 
and "back colors" components are a means of specifying another, specialized 
type of dependent data. Specifically, the renderer requires that each object 
in a scene have at least one of these components. The 
"front colors" and "back colors" components specify colors to be associated 
with the front and back sides, respectively, of a surface. The 
"colors" component specifies colors to be associated with both sides of 
a surface, or with a volume. If only "front colors" or 
only "back colors" are specified, then only the "front" or "back" 
sides, respectively, of the polygons are rendered. If present, "front colors" 
or "back colors" override the specification of the "colors" component. #!N 
#!N Each item of a color component Array consists of three 
floating-point numbers specifying the red, green, and blue component of a 
color respectively. The color components can use the entire floating-point range, 
but by convention the range from 0 to 1 is mapped 
onto the available range of the output device. Like the "data" 
component, the color components can be position- or connection-dependent. #!N #!N 
The front of a triangle is defined to be the side 
such that the path traversing the vertices in the order that 
they are listed for the triangle appears to go counterclockwise. The 
front of a quad is the side from which the vertex 
numbering appears (  #!Lcuboi24,dxall204 f Figure 24  #!EL  ). #!N #!N The interpretation of colors 
differs between surfaces and volumes. For surfaces, the color values in 
the range from 0 to 1 are mapped onto the range 
of colors values possible for the display. For volumes, the interpretation 
of colors follows the "dense emitter" model described in the next 
section. #!N #!N #!N  #!F-adobe-times-medium-i-normal--18*   Next Topic #!EF #!N #!N  #!Lopacom,dxall208 h Opacities Component  #!EL  
#!N  #!F-adobe-times-medium-i-normal--18*   #!N 
