[Update REQ 6975]: Geomview question

[munzner at cs.stanford.edu]

> I have been using geomview for a while and I was wondering if it is
> possible to save a camera as a PS file from the command line without
> using menu navigation. I am trying to integrate geomview in a tool flow
> and I would like to get the snapshot saved. Well, OK, here is what I
> would like to do:
> 
> Run geomview in batch mode, orient the picture in a certain direction
> and save it as a PS file. All this has to be done in batch mode, no
> camera on screen.

You can do it by starting up Geomview with the right GCL (Geomview
command language) file. Here's an example file, which I called
"doit.gcl":

----------
(progn
(load hdodec.off geometry)
(camera c0 {
camtoworld transform {
   -0.89896667    0.16900851   -0.40410414             0
    0.43307546    0.48121688   -0.76215452             0
     0.0656505   -0.86015731   -0.50578946             0
     1.2306064    -16.264462    -9.6162682             1

}
	perspective 1  stereo 0
	fov 40
	frameaspect 1
	focus 3
	near 0.07
	far 100
}
)
(redraw c0)
(draw c0)
(snapshot c0 /tmp/foo.ps ps)
(exit)
)
----------

You can see that I loaded some geometry and a camera which has a
specific viewpoint, then I tell Geomview to draw the camera and take a 
PostScript snapshot. Finally, the script tells Geomview to exit. 

Then just type at the command prompt

% geomview -c doit.gcl

a window flashes up on the screen, the snapshot happens, and Geomview
exits. 

The way I got the camera specification was by interactively moving the 
camera to the position I wanted it in a previous session, then saving
the camera specification, including it in the GCL file, and inserting
the camera id "c0" in between "(camera " and the rest of the
specification. (You can save the camera spec by hitting ">" in an
interactive session, changing the default "Commands" to "Camera",
change "World" to "targetcam", and give a filename in the browser or
"-" to print it to stdout on your shell. 

Hope this helps,
Tamara