[chimera-dev] accelerators and stereo]

[Greg Couch]

Hi Matt,

I'm responsible for chimera's stereo support.

Can you send me the output of /usr/gfx/gfxinfo so I can figure what which 
graphics option you have.  And I'd also like to know if chimera is 
switching the display into stereo mode or if you do it by hand (for 
instance, because you're displaying remotely on to your SGI).  Chances are 
that if you have a semi-recent SGI workstation you can use an alternate 
stereo mode that doesn't loose as much resolution.

And also please send me the output from "CHIMERA/bin/autostereod -f -v" -- 
autostereod is a daemon that chimera uses to switch the monitor into 
stereo mode on SGIs, -f says to run in the foreground, and -v says to be 
verbose.  You can ^C the program after it outputs which stereo mode it 
would switch the monitor to.  There's a chance that the autostereod 
program is not picking the right stereo monitor (setmon) mode.

Your explanation about the stereo quarter of the screen is confusing to me
because the whole monitor screen is in stereo.  Perhaps you're talking 
about a screen in the X11 sense and you have your X11 screen set to 
1600x1200 and when you switch into stereo, you're getting interlaced 
stereo with 1280x512 resolution?  I'm not sure how else you would get a 
stereo quarter.  Normally, SGI monitors are configured to be 1280x1024 
non-interlaced and older SGIs use an 1280x492 interlaced mode (492 instead 
of 512 to account for the vertical retrace of the monitor between stereo 
frames).  So in interlaced stereo you only loose half of the vertical 
resolution, and not any of the horizontal resolution.

If you're using the SGI defaults, the mouse should always be visible on 
the display, but you may have to move it between the left and right eye 
view by rolling off the bottom (to the top of the other eye) or 
vice-versa.

 	Greg Couch
 	UCSF Computer Graphics Lab
 	gregc at cgl.ucsf.edu

On Tue, 19 Apr 2005, Thomas Goddard wrote:

> Date: Tue, 19 Apr 2005 14:19:03 -0700 (PDT)
> From: Thomas Goddard <goddard at cgl.ucsf.edu>
> To: gregc at cgl.ucsf.edu
> Subject: [matthewd at bcm.tmc.edu: RE: [chimera-dev] accelerators and stereo]
> 
> Hi Greg,
>
>  Do you have any suggestion about this chimera-dev post about ancient
> SGI stereo resulting in Chimera windows being placed off the viewable
> screen?
>
> 	Tom
>
> ------- Start of forwarded message -------
> Matthew Dougherty matthewd at bcm.tmc.edu
> Tue Apr 19 14:16:07 PDT 2005
>
> another thing about stereo.
>
> it would good to have all the dialogs come up in the stereo quarter of the
> display when I am in stereo mode.  it appears the dialogs come up randomly on
> the display. sometimes the main chimera window comes up
> not-on-the-stereo-section of the display so you can't force it into
> monographics.
>
>
> matthew
>
> ------------------------------------------
>     Matthew Dougherty/713-433-3849
> National Center for Macromolecular Imaging
>       Baylor College of Medicine
>
>
> Date: Tue, 19 Apr 2005 15:08:05 -0500
> From: Matthew Dougherty <matthewd at bcm.tmc.edu>
> To: Thomas Goddard <goddard at cgl.ucsf.edu>
> Cc: chimera-dev <chimera-dev at cgl.ucsf.edu>
> Subject: RE: [chimera-dev] accelerators and stereo
>
>> ===== Original Message From Thomas Goddard <goddard at cgl.ucsf.edu> =====
>> Hi Matthew,
>>
>>  I don't understand what you mean by "the stereo quarter of the display".
>> Is this some special monitor?
>>
>
> standard monitor & graphics hardware.
> when stereo hardware is engaged (ircombine or setmon), the computer reduces
> the display by two on each axis.  It does this to create the left and right
> display
> buffers out of the single monographic display buffer, a limited graphical
> resource.
>
> when it sends out the stereo display buffers it doubles the output pixels,
> hence the objects (e.g. desktop icons) look twice as big.  What used to take
> one pixel to display is now using four pixels.
>
> at the same time the emitter activates the googles, polarizing (making opaque)
> one eye, and transparent the other; on the screen the two display buffers,
> are put on the display, alternating typically 1/30 apart.
>
>
> most people use the top left area/ top quarter, where the tool chest is
> located, typical default for sgi, but can be overridden.
>
> unfortunately, when stereo mode is engaged the screen size is not adjusted
> within the x window manager as it should be (SGI or X design bug), so you have
> anomalies like the mouse being able to go off the visible display, or allowing
> windows to startup off the visible display; because the x window manager is
> working with 1024x1200 (mono) when in reality the display area is 512x600
> (stereo).  This may be solvable by application code.
>
>
>>  Chimera uses stereo in a window provided by the OpenGL graphics library.
>>
> which gets it from the x window manager
>
>>  Chimera does not provide a way to specify the starting positions of
>> its windows.  Initial placement of windows is usually managed by your
>> windowing system, not by individual applications.
>>
>> 	  Tom
>
> - ------------------------------------------
>     Matthew Dougherty/713-433-3849
> National Center for Macromolecular Imaging
>       Baylor College of Medicine
> ------- End of forwarded message -------
>