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hotspur1 05-02-2003 01:10 PM

v 1.09 problems with STEREO/HMD modes
We are experiencing problems with Vizard in HMD | STEREO modes with version 1.09 that we did not experience with v1.08

We are running Vizard on a Dell Workstation 450 with a dual head nVidia Quatro4 900XL card. When we issue the standard

viz.go(viz.HMD | viz.STEREO)

the window only expands to approximately 640x480 with two viewports for the l/r eyes. It actually overlaps slightly onto the 2nd monitor, but only 20-30 pixels. We, of course, wish the display to stretch across 1280x480, which it used to do.

Do you have any suggestions for workarounds at the moment? We haven't changed the machine drivers or anything like that. None of the hardware has changed. This problem occurs in v1.09 and a special version 1.07 that was modified to include a viz.noprojection() (among other things) by ACB that is discussed in another thread. We getthe right behavior with v1.08.

Thanks for any help.

tobin 05-04-2003 11:07 PM

Thanks for letting us know about this. While we're not aware of any changes that would affect fullscreen mode, but we want to resolve this issue immediately for you. We'll email you directly a couple of executables that we'd like you to try and see which replicates the behavior you're talking about.

The other possibility is the slightly new way that XP seems to handle multiple screens may be causing the problem. We need to look into this more thoroughly and should probably post an general recommendation.

hotspur1 05-15-2003 12:19 PM

I've done a little more debugging on this problem and I find that I have the same problem on another machine that has the ATI Radeon 9700 card on it. I am using the digital and analog outputs for a dual monitor setup and the OEM provided drivers. So perhaps the problem is not Quadro card specific.

When I use viz.go(viz.FULLSCREEN) the display spills over partially onto the second display. Using HMD|STEREO modes is messed up as well.

On the other hand, when I use a GeForce4 MMX dual headed card, I don't have a problem. I noticed that the GeForce4 driver treats the two monitors as a single 1280x480 monitor rather than using default Win2000 multi-monitor support (which is used by the other two setups)

Unfortunately, I don't have any PCI cards around with which to test this with two separate cards.....

Any luck debugging from your end?


hotspur1 05-19-2003 03:35 PM

version 1.096
This newest version (1.096) seems to help matters on the ATI Radeon card, but the display on the quadro card is still incorrect. Version 1.09xacb with the actual F2 hotkey to make it full screen worked on the Quadro, but somehow, it doesn't work automatically.


hotspur1 05-20-2003 02:38 PM

Just a follow-up on my last post. I was in error that the F2 command isn't working. It turns out that the graphics window was not the active window, so I guess it was not getting the keypress messages.

Is there a way to guarantee that the graphics window is the active window and not the editing window?


unabhan 07-29-2003 10:20 AM

Display devices/ HMD etc
I'm setting up a new VR-lab with Dell Workstation 650 with nVidia Quatro4 900XGL and NVIS nVisor FX HMD (1280x1024 pix max res).
I need more information about display devices - is the resolution from windows used or can it be set in vizard?
BTW, I get these effect with viz.FULLSCREEN spilling on the 2nd screen as well as the need of the F2 hotkey to stretch stereo to both displays (using viz 1.098).
Any news on that?
Thanks Agnes

tobin 07-30-2003 02:52 AM

Vizard will deploy fullscreen mode at whatever resolution you are currently running windows under. So, you should set up your winhdows desktop to the desired resolution before starting your script in HMD mode.

We have gone ahead and made available the beta version of Vizard Release 2. It is quite stable and you may want to go ahead and give it a try. You can download it now off the main download page. It handles fullscreen slightly differently, and makes available F1 (htm help), F2 (fullscreen), F3 (wire/poly), and F4 (framerate) hotkeys always.

Most of our team is currently at Siggraph so we apologize for being slow in responding to you inquiries.

unabhan 07-31-2003 04:57 AM

frame parallel mode/viz2.0 problem
I've downloaded and installed vis2.0 on our workstation.
What I get now unsing one of your stereo-quickworld files is
no more spilling on second screen as in viz1.98 using viz.go(viz.FULLSCREEN) - and with viz.go(viz.FULLSCREEN|viz.STEREO) a horizontal split screen on my primary display without (or is there any) option to stretch to both montors.
Any idea? :confused:

dioselin 09-02-2003 07:44 AM

Stereo with nVidia Quatro4 900XL card
We are working with a nVidia Quatro4 900XL card in Windows XP too and we are encountering the same problems as posted in the first message.

What I found is that if you configure XP not with 2 monitors but with only one with 'Horizontal span' then each monitor gets an image but with some weird perspective distortions.

any way to correct this?


tobin 09-02-2003 09:47 AM

You are absolutely right about using horizontal span. In fact, using the other method (dual view) with nVidia hardware results in significantly slower performance because the rendering is not 100% OpenGL accelerated. Below is one of our tech notes on this issue.

But to address your concern about the distortion, a minor error in how Vizard computes the aspect ratio of multi-display systems has been discovered in the most recent release of Vizard R2 and has been corrected in the upcoming 2.11 release. A temporary work around is to multiply the viewport's aspect ratio by 2.0. In script form, apply an aspect ratio of 2.67 instead of the typical 1.33 of most displays:


# 50 deg horz. FOV, 2.67 horz-to-vert aspect ratio
viz.fov(50, 2.67)

We apologize for the inconvenience. Below is a fuller discussion of the nVidia issue:

Tech note on nVidia dual view versus horizontal span:

rdotsch 09-05-2005 08:38 AM

Same problem
I have more or less the same problem as has been described above. I'm using Vizard 2.51c, a NVIS nVisor SX HMD and a PNY graphics card equipped with the Nvidia Quadro FX 4400.

I have horizontally spanned the desktop and when I run a vizard program (using viz.go(viz.PROMPT) and selecting Stereo and Fullscreen, the image for the left eye is cut-off and continued on the next eye, and the image for the right eye has been shifted to the right and I cut-off.

When I run the same program in a maximized window (which stretches accross left and right eye) everything's ok.

Is this a problem specific to the new Quadro FX 4400 chipset?

Kind regards,

Ron Dotsch

PS. The technotes about the nvidia chipset issues mentioned in a previous post weren't available at this moment.

Edit: I have tried changing the FOV and aspect ratio as shown above. Didn't help.

mspusch 09-05-2005 08:58 AM

Hi Ron,

I can not answer the technical details concerning your question, but I have updated the link to the nVidia setup page above.


Hope this setup info helps. I have personally seen an error like the one you describe only when the screen resolutions for left and right screen were different for some reason.

All best,


rdotsch 09-05-2005 11:37 AM

Thanks for updating the link. I've read through it, but I believe I did everything by the book.

Also the resolutions are the same, so that couldn't be the problem as well.

The only thing that I can think of is that I have a second graphics card in the pc, which I use as a desktop. That one is set to a lower resolution. Could it be that in fullscreen mode vizard takes the resolution of that graphics card while using the quadro card for output, which might explain the shifted displays?

Kind regards,


tobin 09-05-2005 01:56 PM

Very likely it's the fact you've got 2 cards running at different resolutions. This is interesting :) What you ought to try now is manually forcing Vizard's resolution (and perhaps position). You can do this using the


commands. Hopefully these will solve the problem. I've never actually tried a 3 monitor / dual card setup but I will do so if you're still having trouble so we can solve this.

rdotsch 09-06-2005 03:50 AM

Thanks for the pointers. Now I don't have to maximize the window anymore, but I the output is still in a window, not fullscreen. The problem is that putting the line

viz.windowsize(2560, 1024)

viz.go(viz.STEREO | viz.FULLSCREEN)
immediately undoes the viz.FULLSCREEN command.

I have tried repositioning the window so the titlebar will be cut-off by the screen using

viz.windowpos(-2, -30)
but that didn't work out too well: it did what it needed to do, but 30 (or less) pixelrows of the windows background wasn't covered. Setting the windowsize to (2560, 1054) instead of (2560, 1024) didn't help; I can't seem to set the windowsize to more than 1024 pixels vertically.

So it's a dead-end at this point.

Is there any other way I can let vizard know what resolution I want to use?

edit: Being Dutch I usually have to edit my post again to get rid of all kinds of spelling errors. :)

tobin 09-06-2005 01:09 PM

Yes, there is the viz.displaymode() command, which must PRECEDE your viz.go() command. You probably want something like this:


Hope that helps!

rdotsch 09-08-2005 05:18 AM


viz.go(viz.FULLSCREEN | viz.STEREO)

didn't work for me. I get the same results as when I don't use the viz.displaymode statement. When I set it to other values (1280,1024) or anything else, I either get the following error:

ERROR: Failed to set requested display mode

or it doesn't help. :(

tobin 09-08-2005 06:36 AM

OK, can you please describe your exact system configuration so we can put it together here and figure out how to solve this. Please tell me the graphics cards, what kind of outputs each has and what you're using, at what resolutions, and in what order (primary display, etc). Basically describe enough so that we could replicate your monitor & HMD configuration.


rdotsch 09-08-2005 03:02 PM

I will post all this information next week, because I won't be in office until then. Thanks in advance for your great support!

By the way, just for the record: when I disable the second graphics card, everything works fine.

rdotsch 10-17-2005 03:29 AM

I'm sorry I did not get back at this earlier. I wasn't able to due to holidays and illness.

We have decided to remove the second graphics board for now. Everything works perfectly, I have no troubles running vizard in fullscreen mode now. So the problems were indeed related to the second graphics board. Within the next couple of months, we will do some additional testing and try to get everything working with the second graphics board. I will let you know whether we get it working or not.



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