Hi John! I also have these kind of problems when I use "lazy rendering" which is the way I want it to be done in my application.
These methods may help you: osgDB::setExpiryDelay PagedLOD::setNumChildrenThatCannotBeExpired You can also override these virtual methods to fine tune what you want to do: osgDB::removeExpiredSubgraphs PagedLOD::removeExpiredChildren I hope it can help you in your case even though these are not any good permanent solutions for any "lazy rendering" app.. /Jakob Ruhe 2008/7/30 Glenn Waldron <[EMAIL PROTECTED]>: > John, > > I have run into the same issue. PagedLOD children "expire" after a certain > period of time (default is something like 5 seconds?) If a PagedLOD child > has not been visited in the last N seconds, the pager will discard it and > revert to a lower LOD. OSG updates the "time-last-visited" during the cull > traversal in order to check for expiration. So, if you are not continuously > running the frame loop, PagedLOD's will think their children have expired > and will drop to the lowest LOD. > > I used to refer to the technique you're using as "lazy rendering" (i.e. only > render a frame when something has changed) ... try searching the archives > ... but at the time I never did find a good way to do this in OSG without > confusing the pager. > > Glenn > > -- > Glenn Waldron : Pelican Mapping : http://pelicanmapping.com : > +1.703.652.4791 > > On Wed, Jul 30, 2008 at 8:39 AM, John Vidar Larring <[EMAIL PROTECTED]> > wrote: >> >> Hi all, >> >> Background: >> ----------- >> In our application the user can set up scenes ( or sequences as we call >> them) for playback on a timeline (e.g. seq.1 - transition - seg.2 - >> transition ... seq.N). Some scenes are too complex to render real-time and >> are recorded to movies before playback. Hence, when scenes are edited by the >> user all scenes are redrawn as needed rather than continuously to avoid >> sluggish GUI response. >> >> Problem: >> -------- >> _Sometimes_ when the scene is redrawn in edit mode (i.e. redraw only if >> needed), the pagedLOD DB (osgTerrain) drops to the lowest detail level (Ref. >> osg_original.jpg and osg_problem.jpg). This behavior seems to appear at >> randomly. In playback mode (i.e. when frame rate is constant) the problem >> never occurs. >> >> Reproduce / Code example: >> ---------- >> The problem has been reproduces in a small test program >> (osgtest_source_code.tgz) derived from the osgviewerQT example (since we are >> using Qt 4.x in our application). To reproduce: run the compiled >> application: 'osgtest -t <your osgTerrain db>' . To trigger refreshes, >> occlude parts of the window with another window. The problem typically >> reveals itself when at a redraw or when the window looses focus (be patient, >> since this happens randomly it may take some time before the problem >> occurs). >> >> Since I'm still quite new to OSG, I'm not sure where to look for a >> solution. Hopefully someone will spot the obvious error in the sample code. >> Any advice is highly appreciated. >> >> Versions: >> --------- >> OSG svn rev 8700 >> Qt 4.2.3 >> >> Best regards, >> John Larring >> >> -- >> This message has been scanned for viruses and >> dangerous content by MailScanner, and is >> believed to be clean. >> >> >> _______________________________________________ >> osg-users mailing list >> [email protected] >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
