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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

1305.0. "Save-Unders and Cat-eyes?" by NNTPD::"[email protected]" (Ken Miller) Tue Jun 03 1997 15:36

Hi,

We've got a customer down here complaining about slow repaints under
DB's relative to HP.

We've got:

  - ALPHAstation 500/500
  - PowerStorm 4D60T (Cat-eyes) Rev. A
  - Digital UNIX V4.0B, Open3D 4.3 (also confirmed on V3.2G and Open3D 4.2)

And an xdpyinfo shows that save unders and backing store are *not* supported.

Is this a mistake?  How do we get decent repaints out of Cat-eyes?  His 
application is heavy 3D, but the problem shows up with 2D apps as well.

Thanks in advance,

           == ken miller ==
----------------------------------------------------------
 [email protected]         http://www.gsg.dec.com/miller
  Digital (Metro DC Area)   FGR Engineering, COP Facility
  PGP  '96 1F 82 38 7A 38 6C ED  E5 9C 81 D2 D2 74 87 04'

[Posted by WWW Notes gateway]
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1305.1WRKSYS::CHALTASIntelligence is no bad thingTue Jun 03 1997 17:1728
    Well, it's a little more complicated than that, but first:
    
    How did you get a PS 4D60T to run on UNIX V3.2G?  Unix V4.0 is the
    minimum rev. for this board.
    
    Now the relevant answers:
    
    Save-Unders & Backing Store are disabled by default.  You can
    enable them by editing the string "-bs -su" out of
    /usr/lib/X11/Xserver.conf
    
    Don't edit out anything else, then restart your X server (reboot
    is the easiest way).
    
    You still won't have save-unders for everything -- but note that
    save-unders are *never* guaranteed (per the X11 spec).  Save-unders
    have performance side effects of their own (notably, the use video
    memory, which is a scarse resouces) which can *adversly* effect
    performance -- that's one reason they are generally turned off.
    
    Also, I'm pretty sure that save-unders *only* work on X11 stuff, and
    not on OpenGL buffers -- but someone may correct me on this.
    
    Now -- are you sure that you understand what the customer means by
    slow repaints?  It's possible that lack of save-unders isn't the 
    real problem.
    
    George
1305.2Thanks.BALTMD::GLOCKWed Jun 04 1997 09:2022
    
    I have been working with Ken and the customer on this.  The problem has
    not been seen on DU 3.2-G per 1305.0 ( like .-1 says the 4D60T is not
    supported), it has been seen on DU 4.0-B with Open3D 4.2 and 4.3.
    
    The customer is running a 3D application from Computer Vision (Optegra
    Visualizer).  After dismissing any dialog window that obscures a
    portion of the 3D drawing that portion of the drawing is repainted.
    This is taking anywhere from 5-10 seconds.  The HP box is not redrawing
    the obscured portion of the drawing, it is immediately replaced after
    the dialog window is dismissed (1 sec at most).  
    
    His 3D image is of a control room with lots of furniture etc.  He is
    complaning of a very shakey redrawing of the 3D image when moving around 
    outside of the room (looking at the room from a distance).  When he moves 
    around inside the room the motion is very fluid.  Could this also be
    caused by the lack of save-unders?  
    
    Thanks for the help.
    
    Karl Glock
    DTN: 339-5244
1305.3it's an application issueWRKSYS::CHALTASRoland the Headless Thompson GrapeWed Jun 04 1997 12:228
    Enabling save-unders will probably not help this repaint.
    From your description, it's likely that the HP system is using
    overlays for the dialog window.  Since the HP graphics API is
    probably Starbase, the application's behavior on the HP system and
    the DIGITAL system (which will be using OpenGL) are very different.
    Alas, CV has not been providing very aggressive support for Visualizer
    on the DIGITAl platforms, and doesn't support Overlays on DIGITAL
    platforms. 
1305.4Thanks.BALTMD::GLOCKThu Jun 05 1997 09:335
    
    Thanks for the info.  It appears that again we lose do to lack of
    application support even though we have the best platform.
    
    Karl Glock
1305.5tell SPGWRKSYS::CHALTASSex, Drugs & OperaFri Jun 06 1997 09:402
    Known problem with CV in general.  You might want to share your
    experience with Ralph Campanelli ([email protected])