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Conference bgsdev::open3d

Title:open3d
Notice:Kits on notes 3 and 4; Documents note 223
Moderator:WRKSYS::COULTER
Created:Wed Dec 09 1992
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1306
Total number of notes:5260

1283.0. "Question on DECstereo, different graphics cards." by PEACHS::DALEY ('Course it don't come with @!# wafers!) Thu May 01 1997 19:10

Hi,

Customer questions, follow-up to note 1036 in this conference.

Customer's app ran originally using stereo on L2 card.  Mouse reports
0-1023 pixels along y axis, and he can see all of them.  True with UNIX 4.0b, 
Open3D 4.2...tested here.

On system with 4D20, he gets same number of positions reported by mouse, but
can only see 511 of them.

He has coded around this to make it look right, which is required by stereo
before 4.3 and gl stereo.  Here are his questions:

- Are these the only to instances to worry about with older cards & stereo:
  1024 visible or 512 visible?  Are there other modes?  Or will he just have 
  to play with each card his customers might have, each resolution, etc.

- Is this a function of memory on the card, the video driver, or what?

Any light you can shed is appreciated.

Regards, 

John Daley
CSC/ALF
----------------------------------------------------------------------
From the customer:

"        We saw that the behavior of the mouse is different on various
interlaced stereo systems systems.  In particular on a ZLXp-L2 system
running Open3D 3.4 and OSF/1 3.2, the mouse vertical range in stereo is
from 0 to 1023.  On a 4D20 system running Open3d 4.3 and DU 4.0a, the
*visible* mouse vertical range is 0 to 511, but it still can move in the
512 to 1023 range.

"        (This is not an issue on the 4060T because it has much better
stereo support -- i.e. quad-buffered, square pixels.)

"        The question is what is the cause of the behavior?  Is it the
particular graphics card?  Open3D version?  I don't particularly care
which behavior is the "bug", but I want to know if those are the only
two stereo mouse modes?

"        To give some background, our molecular modelling software is
in use at over 300 sites worldwide, and we're about to distribute a
new release, so I'll probably modify the code to work in both cases
using a user-controlled configuration switch.  What is needed is an
explanation of when the switch is needed."
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