hi all, I'd like to jump in on this conversation. We are currently in the camp of doing intersection testing against a non-rendered, high-resolution, non-paged terrain model, and then using a PagedLOD terrain model for viz. >From all the comments, it seems like trying to combine the IntersectionVisitor and the database pager is a bad idea if you are also wanting to visualize the same scene graph. Our application is similar to Wojciech's, in that we don't want to pay the overhead of reloading the highest level LOD every time we do an intersection test. We are extracting regular gridded height fields off the terrain data, and then doing line lots of sight checks between the height field points and some other point in the scene.
I have two questions relevant to this thread: 1) Does the task of combining the database pager with the IntersectionVisitor (while ideally caching the highest LOD tile) get easier if you're not actually rendering the scenegraph? 2) Again with respect to a non-rendered, PagedLOD terrain, do you see any problems with running multiple threads where IntersectionVisitor is executed in those threads? We currently do this against our own static BSP tree representation of the scenegraph, and it works fine. We would very much like to do these analyses on very large terrains, but even at 64 bits we will very easily run out of RAM when we try to load them. This makes using an OSGDEM/PagedLOD terrain for the intersection testing the next logical step. Thanks, Dan On Tue, Nov 24, 2009 at 6:54 AM, Robert Osfield <[email protected]>wrote: > Hi Wojtek, > > On Tue, Nov 24, 2009 at 1:33 PM, Wojciech Lewandowski > <[email protected]> wrote: > >> When I get on to reviewing the multiple viewpoint issue with > >> DatabasePager I'll have a think about the consequences of users > >> caching subgraphs. > > > > Thank You. Does it mean I should try to prepare the proposed submission > or > > not ? > > You can submit changes, I can always just use these as another point > of information when doing my investigation even if the code doesn't > make it into svn/trunk. > > Robert. > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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