Paul Martz wrote on Tuesday, May 05, 2009 8:45 AM: > Not sure why you would need to place the vegetation _exactly_ on the ground > for anything other than the highest LOD. Presumably, for lower LODs, the > eyepoint would be too distant to notice any issues. If you agree, then you > could use an LOD=savvy tool like ElevationSlice to get the elevation of the > highest LOD, and place your vegetation there and not bother trying to change > it.
Depending on the LOD data, this could cause the vegetation to be placed under the terrain, effectively causing it to disappear at certain distances. It still might be acceptable, though, depending on the requirements of the project. > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jan > Sent: Tuesday, May 05, 2009 2:38 AM > > 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? -- Bryan Thrall FlightSafety International [email protected] _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
