VolPack is a library for rendering three dimensional data. It uses voxels and shear-warp factorization to turn the three dimensional data into two dimensional images.
Display of the data can be done using a Tcl/Tk program called vprender. Building VolPack was fairly easy. Building vprender was a royal pain.
The VolPack distribution is at ftp://graphics.stanford.edu:/pub/volpack/volpack-1.0b3.tar.Z. It compiled cleanly after downloading.
./configure --prefix=$HOME
make
make install
was all that was needed.
Vprender was more troublesome. Vprender is found the same place as VolPack; ftp://graphics.stanford.edu:/pub/volpack/vprender-2.0b.tar.Z. It did not compile cleanly. In fact, it requires a ridiculous number of supporting files in order to run. Not only does it need (old, obsolete) versions of Tcl and Tk, but it needs object-oriented extensions to Tcl, and some graphics extensions ( photos, tiffs) to tk.
The first two supporting packages, Tcl and Tk, installed very nicely.
./configure --prefix=$HOME
make
make install for each was about all that was
necessary. This is quality software.
Other files were not as easy. photo-2.4.tar.gz required patching the Tk installation, and rebuilding Tk. This was one of the more successful endeavors.
Itcl (object-oriented Tcl) made me uneasy. The package didn't use GNU Autoconf properly; it's use was awkward at best. When Autoconf works properly, everything is great, so the mishandling made me awkward. But things worked out okay in the end. Itcl compiled successfully, although not as a shared library.
At first, I didn't want to build the tiff library,
because it's configure script didn't even
understand the --prefix option. However, I
had no choice. Vprender wanted the tiff code. Bleargh.
I configured with ./configure -with-CC=cc.
This still didn't work properly. The guy who wrote this
should learn how to generate proper Autoconf scripts. I
had to manually type in where I wanted the files to go.
I ended up with configuration parameters of
[ 1] Directory for tools: /u1/mit-26/bin
[ 2] Directory for libraries: /u1/mit-26/lib
[ 3] Directory for include files: /u1/mit-26/include
[ 4] Directory for manual pages: /u1/mit-26/man
[ 5] Manual page installation scheme: sysv-source-cat-strip
I then built it, using make and make
-install. What a mess. I have no respect for this program.
I finally got libtiff built. Building vprender was still
frustrating, because the vprender program didn't use
Autoconf any better than the tiff library did. It couldn't locate
libraries that I had just finished installing all around
it. It couldn't even locate -lX11! I had to
tweak quite a bit by hand to get things to work. What
finally made things work is when I added lines
/usr/openwin/lib \
$HOME/lib \
to the VPR_LIBRARY_PATH in config.paths, and
/usr/openwin/include \
$HOME/include \
to the VPR_INCLUDE_PATH in config.paths.
But I'm very disappointed that configure wasn't smart enough to
locate -lX11 on its own.
Once configure finished, I tried to
make the code. This was treacherous, too.
I got many errors that I did not fully understand. I
resolved them by making changes that seemed as innocent as
possible, until the compiler stopped complaining. It
worked okay. I was able to get by with a minimum of
mysterious changes.
The ftp machine
graphics.stanford.edu
has a nice
directory of data files
which can be used to test the rendering abilities of
VolPack. I downloaded all of the data. To test it, I
would have to run the vprender program.
But I couldn't run the program! Trying run it gave the error message:
ld.so.1: vprender: fatal: libtiff.so.3: can't open file: errno=2
Killed
So, I was frustrated. I recompiled, except this time I
explicitly included the file $HOME/lib/libtiff.a
on the link line, instead of calling it as
-ltiff.
Finally. It ran.
I linked the data files from the stanford site into the
demo directory. The program vprdemo runs the
programs just fine. Some of the data sets are large:
[~/src/vprender-2.0b/demo]% ls -lF ../../data/*/*{den,vprdemo}
-rw-r--r-- 1 mit-26 10944574 May 20 ../../data/brain/bigbrain.den
-rw-r--r-- 1 mit-26 5276 May 20 ../../data/brain/bigbrain.vprdemo
-rw-r--r-- 1 mit-26 7143486 May 20 ../../data/brain/brain.den
-rw-r--r-- 1 mit-26 1376318 May 20 ../../data/brain/brainsmall.den
-rw-r--r-- 1 mit-26 5289 May 20 ../../data/brain/brainsmall.vprdemo
-rw-r--r-- 1 mit-26 7209022 May 20 ../../data/engine/engine.den
-rw-r--r-- 1 mit-26 8140 May 20 ../../data/engine/engine.vprdemo
-rw-r--r-- 1 mit-26 14745662 May 20 ../../data/head/bighead.den
-rw-r--r-- 1 mit-26 5298 May 20 ../../data/head/bighead.vprdemo
-rw-r--r-- 1 mit-26 6888 May 20 ../../data/head/face.vprdemo
-rw-r--r-- 1 mit-26 7405630 May 20 ../../data/head/head.den
-rw-r--r-- 1 mit-26 9425 May 20 ../../data/head/head_skin.vprdemo
-rw-r--r-- 1 mit-26 1851454 May 20 ../../data/head/headsmall.
