Re: [Closed REQ 5834]: question about bitmap output from geomview

[daemon]

There are a couple of ways you could get images out of geomview on the
DEC Alpha.


1) "xwd", the X window dump program, can grab a screen snapshot.  If you have
	the (free software) pbmplus package of programs, you can convert xwd
	images to some handy format, like ppm or tiff.  You might invoke it
	from a GCL script you feed to geomview, with something like:

	  (geometry yourobject < anotherfile)	# Or whatever you need to
						# load the appropriate data

	  (redraw Camera)		# Supposing your camera window
					# is named "Camera", as is
					# true by default,
	  (draw Camera)			# (redraw ...) followed by
					# (draw ...) should ensure
					# that the screen is up to date.

	  (! xwd -name Camera | xwdtopnm | pnmtotiff > whatever.tiff)
					# Use geomview's "!" shell-escape
					# to invoke the window snapshot,
					# and use (e.g.) the pbmplus programs
					# "xwdtopnm" and "pnmtotiff".
					# Note "xwd -name Camera" assumes
					# the name of the window; Geomview
					# creates the X window tagged with the
					# same name as appears in the
					# object browser.

	  (geometry yourobject < yetanotherfile) # next frame
	
	You'll need to take care that the camera window is never obscured.

	The pbmplus package is widely available by anonymous FTP,
	for example at ftp.x.org as contrib/utilities/netpbm-1mar1994.tar.gz.
	

2) You could pick up a pre-release of the next version of geomview.
   A compressed binary is at geom.umn.edu as priv/slevy/gvx.alpha-X11.gz;
   after decompressing and chmod +x'ing, this is a direct replacement for
   .../Geomview/bin/x11/gvx.  (Save the old gvx in case of trouble!
   Or, decompress it elsewhere, and ``setenv GEOMVIEW_GVX path_of_new_gvx''.)


   It includes an internal snapshot facility which directly writes 24-bit
   ppm images.  You'd invoke it as

	(geometry ... )			# Load scene

	(snapshot Camera  whatever.ppm  ppm)	# Take PPM-format snapshot

   	(geometry ... )			# Load next scene

   etc.  The "filename" argument to the PPM snapshot program can actually
   specify a Bourne shell command.  For example:

	(snapshot Camera  "|pnmscale .5 | pnmtotiff > whatever.tiff"  ppm)

   where the leading "|" (vertical bar) denotes a shell command.
   (I mention "pnmscale", another pbmplus program, since it provides a sort of
   anti-aliasing.)

   This route will probably produce better-looking results than using "xwd",
   since it uses full 24-bit color rather than the dithered 8-bit you
   probably get on your display.


Good luck.