Serving and Viewing
OFF 3D Object Files
Now you can embed links to OFF 3D Object files in your Web pages
(just like you can embed links to GIF files) and you can get your client
(Netscape|Mosaic|etc.) to automatically invoke viewObject to view them
(just as it automatically invokes xv to view GIF files).
The OFF format has several files associated with the description of one objects.
- The aoff file which tells you about all the other files and attributes.
- The geom file which contains the geometry
- The pcol file which contains the polygon colors if any
- The vcol file which contains the vertex colors if any
- The pnorm file which contains the polygon normals if any
- The vnorm file which contains the vertex normals if any
I have added the following extensions
- The anim file which contains an animation sequence through transformations
- The fly_prp and fly_vpn files which contain an animation path
The preView_3d system is a viewer for 3D OFF objects.
The page where you came from
(preView_3d homepage)
contains a list of features the viewer supports as well as examples of objects.
This page gives you instructions for serving and viewing OFF files via
the Web based on the assumption that you are using NCSA's httpd server
If you can tell me how to amend our instructions for other Web servers
and browsers, please let me know at: gaitat@vnet.ibm.com.
Installing viewObject as an External Web Viewer
You can install viewObject on your Unix workstation and tell your Web browser
to invoke it as an external viewer for OFF files (just as it invokes xv to
view GIF files). Just follow these five steps:
- Get the source from
ftp://ftp.x.org/contrib/pex/pexView_3d-1.2.tar.Z.
- Enter the command "zcat pexView_3d.tar.Z | tar xf -".
- Enter "make IBM" of "make HP" or "make Sun" depending on what machine you
are on. If everything went well, you should have several executables ready
including viewObject in whereyouinstall/pexView_3d/viewObject/viewObject.
viewObject is only a script and you need to change its first line depending
on where you installed. I would also suggest not moving things around but
making a link from somewhere in your path to the viewObject script.
ln -sf whereyouinstall/pexView_3d/viewObject/viewObject viewobject, should
do the trick.
- Add the following line to the .mime.types file in your home directory
application/x-viewObject aoff geom bgeom pcol bpcol \
vcol bvcol pnorm bpnorm \
vnorm bvnorm anim fly_prp fly_vpn
- Add the following line to the .mailcap file in your home directory
application/x-viewObject; viewObject -o %s -URL %u ;
NOTE: Be sure the executable viewObject is in your path.
See Lawrence Livermore National Laboratory's
WWW Viewer Test Page
for information about many different Web media and their viewers.
Embedding Links to OFF Files in Web Pages
You can embed links to OFF files in Web pages in exactly the same way that
you would embed links to GIF files. The names of OFF files must have the
aoff extension (just as GIF files have the .gif extension). They may have an
additional extension if they are compressed.
For example,
BOTTLE
is an embedded link to an OFF file on my server.
It was generated with the HTML text:
<A HREF="objects/bottle.aoff">BOTTLE</a>
If you've installed viewObject as an external viewer then you can click on
this link to make sure that your installation was successful (but first you
need to exit your Web browser and restart it after setting up the .mime.types
and .mailcap files).
To serve OFF files from your Web server you need to add the following lines
to the resource configuration file (often named srm.conf if you are using
the ncsa httpd server) for your server, so that these extensions are
registered as Media subtypes:
AddType application/x-viewObject .aoff
AddType application/x-viewObject .geom
If you embed links to OFF files in your Web pages, you may want to add text
telling people that they need to install viewObject to view these files,
and you may want to include a link to this page to tell them how to do it.