[osg-users] Strange behavior with multiple screens and ImageStream

Kawicki, Ryan H Ryan.H.Kawicki at boeing.com
Thu Sep 11 07:18:22 PDT 2008

I am not an expert in this area, but our application seems to suffer
from this as well.  I don't think this has to do with OSG.  I believe it
to be more driver related.
Do you have VSync turned on?  If you do, force VSync to be always off
and retest.

Ryan H. Kawicki 
The Boeing Company 
Training Systems & Services 
Software Engineer 


From: Serge Lages [mailto:serge.lages at gmail.com] 
Sent: Thursday, September 11, 2008 4:53 AM
To: OpenSceneGraph Users
Subject: [osg-users] Strange behavior with multiple screens and

Hi all,

We've made an ImageStream using FFmpeg to display movies on textures,
but I am currently facing some problem when displaying this movie on two
different contexts. Here is my setup :

WinXP with one GForce 8600GTS and 2 screens, viewer on
DrawThreadPerContext mode (OSG SVN head version).

When I only have one screen but two windows (with a different context
per window), everything works fine, the movie is displayed on the 2
windows without any problem. When I plug a second screen, and I keep the
same setup (2 windows rendered into the first screen), I have a huge
frame drop (more than 20 fps) when rendering my movie (note that in this
configuration, nothing is displayed on the second screen). Same thing
happens if I use the 2 screens (with each window in full screen mode on
each screen).

I really don't understand why adding a new screens make this difference,
moreover it's the only thing in my application that suffer like that
from the second screen. Does it ring a bell to someone ?

Thanks in advance !

Serge Lages

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openscenegraph.org/pipermail/osg-users-openscenegraph.org/attachments/20080911/b8286bd2/attachment-0003.htm>

More information about the osg-users mailing list