VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Fri Mar 17 2000 - 16:18:09 CST

On Fri, Mar 17, 2000 at 07:48:50PM +0100, Timm Essigke wrote:
> Dear Dr. John Stone,
>
> time went on and a lot changed on the Linux-system. So I would like to
> ask some more questions about stereo graphics on Linux:

Certainly.

> John Stone wrote:
> > On Sat, Jan 15, 2000 at 05:11:49PM +0100, Timm Essigke wrote:
> > > All our newer machines are Linux-boxes. Is there any support of stereo
> > > graphics planed? Graphic cards with shutter glasses for PC got quite
> > > cheap recently. Has anybody experience with them?
> >
> > VMD supports stereo on all platforms that have a real GLX implementation that
> > provides "quad buffered" or "stereo in window" stereo support. In the case
> > of Linux only the commercial OpenGL servers provide this at the moment.
>
> I found a free GLX implementation for Matrox G400 cards we have
> (http://utah-glx.sourceforge.net/).
> Is it possible to build a VMD-version for it?

Yes, you should be able to compile your own VMD from the source code,
and link it against a build of Mesa with that Utah-GLX. We don't have
any Matrox boards here, so I can't do it for you though. I'm happy to
answer questions you have about compiling VMD once you get the Mesa
and GLX working on your machine. Another VMD user has said that they
are going to try compiling VMD with that setup, but I haven't heard anything
from them about it yet.

> > In the near future XFree86 will finally be providing a real implementation
> > of GLX. Although I have not personally looked at how complete it will be,
> > I would be very surprised if they don't implement stereo support in their GLX
> > implementation.
>
> We will probably buy Voodoo3 cards because of there hardware
> acceleration provided by XFree86/4.0
> (http://www.xfree86.org/4.0/RELNOTES2.html#12). What is to do to uses 3D
> graphics in VMD with them?

In order to get hardware acceleration in VMD, you just have to compile VMD
yourself, and link it against the Mesa that comes with that version of
XFree86, and it should work fine.

> > There are several consumer priced video boards available
> > already which have the "Vesa stereo connector" on them. We have a PC
> > with stereo sync outputs, but its a Windows NT box.
>
> I know that ELSA and ASUS have video boards with stereo connector and
> glasses. As far as I know, they do not provide any support for Linux for
> them and I haven't read about a support of these glasses by the XFree
> project. Have you more information on this subject?

Not yet. I don't know of any boards that do stereo on Linux yet, other
than possibly some commercial X-Servers.

> We have some Eye3D stereo glasses
> (http://www.iart3d.com/eiart/product/eye3d/eye3d.htm,
> http://www.stereo3d.com/eye3d.htm) for testing purposes and I tried to
> get them working with VMD. They work with a VGA dongle between the video
> card and the monitor and I hoped they are hardware independent enough to
> work without any special Linux drivers. Never the less they need a
> support for the line blanking mode by the software. Could you provide me
> with a patch for VMD to uses this mode? I don't know how much work it
> would be to implement it...

Well, if I knew better how this was supposed to work I could write the
code and put it into VMD, but after looking around on those web pages
I still have no idea what their hardware wants an OpenGL program to do
in order to work correctly. If you can find a piece of sample code that
works with these glasses, I could probably make VMD work with them as well.

> We would like to buy them for our PCs if there would be any support in VMD.

Get me some example code to work from and I'll see if I can make the changes.
Since we don't have this hardware though, you're going to have to help us out
here.

> > I know that there are a number of appropriate video boards out there,
> > its all a question of whether or not the video boards you want are supported
> > by the X Server and OpenGL libraries.
>
> I think the major problem are the glasses which are not supported up to
> know. There are X servers for most cards available and some have free
> GLX support now.

True. But even the ones that are "supported" are still in their very
early stages, and may not work perfectly with VMD just yet. We've run
VMD with some of the older XFree86 hacks that did a real GLX and although
it runs, there were bugs in their code still. I'm hoping that things are
much better now. We're going to try and ship a build of VMD that's linked
against the XFree86 4.0/Mesa/GLX code for the final release of VMD 1.5,
but we still have to get one of the machines here running it well.

> > VMD is the last link in the chain,
> > and is the cheapest and easiest to tweak for your purposes if necessary.
>
> But it is the most important for us. While we can choose the video card
> for the next computers we will buy, there is no other software available
> which is as good as VMD for our purposes - THANK YOU VERY MUCH FOR IT!
> So, tell us which video board/glasses are the easiest for you to give us
> support for in VMD.

On Linux, I still don't have a good answer, but perhaps someone else on
this list has more experience with the new XFree 4.0 and the quality of
the existing drivers for the boards that are out there...
If I were to guess, the best low-cost board out there for VMD is likely
to be the NVidia GeForce256, because it has hardware acceleration for
transforms and lighting, which is something that VMD does a LOT of.
Since this is a relatively new board, the drivers (if any) for Linux
are probably very weak still, but eventually this board will probably
be a very good choice for running VMD on linux. I don't have any idea
about whether there's a version of that board that does stereo though...

> > So, you need to decide who to get your X server and OpenGL libraries from
> > first, but once you know what you want I would be happy to work with you
> > to build a VMD binary for your system, whichever route you decide to go.
>
> We would highly appreciate any help you can give us!

On the Linux front, we're not much farther ahead of you yet, we're just
figuring out a lot of this ourselves. Perhaps others on VMD-L have
suggestions or comments though??

Thanks for using VMD!
  John Stone
  vmd_at_ks.uiuc.edu 

-- 
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