> > Message: 2 > Date: Thu, 01 Apr 2010 09:13:21 -0400 > From: Jean-S?bastien Guay <[email protected]> > To: OpenSceneGraph Users <[email protected]> > Subject: Re: [osg-users] looking for a terrain database building > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi Terry, > >> Both VPB and osgEarth seem to default to building scenegraphs with >> PagedLOD nodes, which I don't think will work for me. One option I >> thought of is to use VPB to create a big database in a single file >> with traditional LOD nodes, then use a separate program to convert it >> all to individual .flt tiles and a Metaflight file or something >> similar. I'll have to do more thinking about this option. Anyone >> know of any alternatives to Metaflight that can describe tiled >> databases but still let you store and edit tiles individually? I just >> want to consider all the options. > > What's the specific problem with PagedLOD? You could still find the tile > you want to modify, convert it to .flt (using osgconv with the flt write > support in recent OSG versions), edit it, reconvert it to .ive (with > osgconv, keeping the name the same) and run it.
Hi J-S. When you convert a file to .flt and then back to .ive, your PagedLOD nodes are lost. More accurately, I think they get turned into regular LOD nodes that don't link to any external files the way PagedLOD nodes do. That's the biggest problem. The new .ive file is also 50X larger than the original and missing its textures, but those problems are probably solvable. > > Is the problem that the multiple LODs for the same region are not in the > same file? That's not just caused by using PagedLOD, but also the fact > that VPB (and I assume osgEarth too) make quadtree-LOD structures. If > you needed all LODs of a given region to be in a single file, then all > the geometry would be in a single file because the lowest-res LOD > contains the geometry for the whole terrain. Tiles become more numerous > and smaller as you go to higher-res LODs. No, I need tiles to be in separate files. The databases we need to build here are large enough that having all LODs in one file will be impractical or impossible. But I want to consider building one big file with LOD nodes as an intermediate step. I'd process that file and split it all up into separate tiles. If I did that I still don't know if I'd build a metaflight description file or something else. > > If you want to make all tiles at all LODs the same size, then I guess > that could be added as an option in VPB. But then what would you replace > PagedLOD with? ProxyNode? I don't understand what you mean here. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
