Hi Robert, On Tue, Nov 5, 2013 at 2:04 PM, Robert Osfield <[email protected]> wrote: > > HI Daniel, > > When running in DrawThreadPerContext and > CullThreadPerCamreaDrawThreadPerContext threading models the dynamic leaves > of the scene graphs are rendered whilst the next fame sits of a barrier so > doesn't run in parallel with them, once all the dynamic leaves are dispatched > to OpenGL the barrier is joined releasing the main thread to start the next > frame, then the remain static leaves are dispatched in a parallel with the > main thread. > > The leaves of the scene graph are the Drawables and StateSet's, the internal > nodes of the scene graph never actually make it into the rendering back-end > data structures that the cull visitor populates and the draw thread reads > from, so the internal nodes of the scene graph are fine to modify as soon as > the cull traversal has completed.
Is it mean that it is not necessary to set data variance to dynamic for nodes like osg::Group (and classes derived from it)? For example, what is the best practices to add a group (of course its children also) to our graph during runtime (is it okay to add/remove child to graph after returning from viewer.frame() ). Moreover, how can we understand whether the cull traversal has completed or not? > > The nodes of the scene graphs must still be only modified single threaded, so > you can't have one thread reading and another thread writing to the scene > graph. If you want to have background thread modify the scene graph then > you'll need to do what the DatabasePager does and maintain a separate scene > graph in the background thread and then merge with the main thread once all > the work on it has been done. > > Robert. > > > On 5 November 2013 11:23, Daniel Schmid <[email protected]> wrote: >> >> Hi all >> >> >> >> I searched the forum already but didn’t find anything that pointed me >> further. My question is the following: When is the correct moment of >> removing/modifying objects from the scenegraph? In my multithreaded context, >> cull and draw run parallel, and in my understanding (and according to code) >> event/update also run parallel to the draw thread. And I cannot put all my >> objects as data variance dynamic only because I want to be able to remove >> them. >> >> How does Database pager resolve this problem? LOD and PagedLOD are not >> DYNAMIC, but still he is able to add/remove nodes savely. Are there other >> ways/moments to do this? >> >> >> >> Regards >> >> Daniel >> >> >> _______________________________________________ >> 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
