Hi Jan, The issue has nothing to do with caching, and everything to do with use LOD's. Once you have multiple LOD's then you'll have multiple elevations for each XY location, and which LOD's that get selected will depend upon the cull traversal for each camera that is viewing the scene - two different cameras could easily require two different LOD for the same position in space.
Given this trying to update the position of objects per frame or trying to detect LOD transistions just isn't practical. What would be pratical would be to place the vegetation directly into the database and let it be paged in with everything else. Robert. On Tue, May 5, 2009 at 9:38 AM, Jan <[email protected]> wrote: > > Hi, > > first of all, i'd like to introduce you to my problem to you. > I have a PagedLOD DB for representing the ground. > On this ground I want to position vegetation also as PagedLOD Nodes. X and Y > Values are fix. > The Problem is that I have to set the vegetation exactly on the ground, using > an intersectiontest works, but if the ground tiles switch from one level to > the other, the position needs to be recalculated because there might be gaps > when getting finer tile resolution. > My first idea was to use osgDB::Registry::ReadFileCallback to check if a node > is paged in. But this doesn't seem to work because the databasepager has > cached tiles and so changing isn't registered. The second idea was to use a > cullvisitor to update all visible vegetation. But if I attach setCullCallback > to a vegetation-node the cullvisitor works just for the root node. Then I > thought of setting CullCallback to all children while creating them. But > then this information will be lost because they need to be saved. I hope it > is clear what I'm trying to do. > Has anyone an idea how to handle this problem or possibly an other approach? > > > > Thank you. > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=11331#11331 > > > > > > _______________________________________________ > 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
