PS Snapshot

[munzner]

>   I am having a problem with PS Snapshot in 
>   Geomview.  Even though "color" is selected and
>   the object is in color, the result postscript
>   file is in black and white.  

The problem is that PS Snapshot only pays attention to color
information that's part of the geometric description of the object
itself. It unfortunately ignores the appearance information wrapped
around the object, which is how color changes made from the Appearance
panel in Geomview are encoded. Here's an example of such an object:

{
#appearance wrapper
appearance {material {diffuse 1 0 0}}
OFF
# 3 vertices, 1 face, 3 edges
3 1 3
# vertex list
0 0 0
1 0 0
0 1 0
# connectivity of the faces
3  0 1 2
}

You can specify a color at every vertex as part of the geometric data,
as below:

{
# keyword for OFF file with color information
COFF
3 1 3
# vertex list includes per-vertex RGBA color information
0 0 0	1 0 0 0
1 0 0	1 0 0 0
0 1 0	1 0 0 0
3  0 1 2
}

The module "Crayola" actually changes colors by altering the geometric
object description. However, the module interface hasn't been ported
to X-Windows yet, so it only runs on the SGIs. 

Hope this helps,
Tamara Munzner