Re: [osg-users] VPB generating terrain for multiple data files
Hi J-S, Have you tried Ben Discoe's VTBuilder (http://www.vterrain.org/Doc/VTBuilder/overview.html)? It _might_ be what you are looking for. Best regards, John Larring Jean-Sébastien Guay wrote: Hi Robert, Ideally should have data throughout your model to define all the heights you require, if you have holes then all you can come if with is an acceptable fudge for what this missing data might be. I know, I know... :-) I work with what our client provided, so I have to fill in the gaps myself. Perhaps the easist way to provide this fudge would be to create a single dummy DEM that covers the entire region and matches the elevations of the tiles you have. The actual data would then act is a high res inserts to this base level DEM. Yes, that was the second option I mentioned. Any hints as to how to do that? I have the FWTools distribution, which includes all gdal binaries, but if there's another tool that I could use, please point me in the right direction. Ideally, I would like the base terrain to conform to the inserts at the edges of said inserts, instead of having steps around the inserts... So the tool used would probably need to interpolate between the tiles. I tried using gdal_merge.py, currently waiting for the terrain to generate from the result of that (I can't use --TERRAIN, so it takes a while)... But it doesn't interpolate, it just puts either NODATA or a value you specify. Anyways, thanks for confirming my intuition. J-S -- Best regards, John WeatherOne -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
Hello John, Have you tried Ben Discoe's VTBuilder (http://www.vterrain.org/Doc/VTBuilder/overview.html)? It _might_ be what you are looking for. Nice, looks like this does what I need! Thanks for pointing thos tool out. J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
Hi J-S, A third option might be to modify osgdem so it allows for non zero default elevation. However, even this is a bit of stop gap. Ideally should have data throughout your model to define all the heights you require, if you have holes then all you can come if with is an acceptable fudge for what this missing data might be. Perhaps the easist way to provide this fudge would be to create a single dummy DEM that covers the entire region and matches the elevations of the tiles you have. The actual data would then act is a high res inserts to this base level DEM. Robert. On Thu, Jul 10, 2008 at 1:52 PM, Jean-Sébastien Guay [EMAIL PROTECTED] wrote: Hello, I am generating a terrain database using osgdem. I have three source data files (GeoTiffs which have correct geospatial information), and I would like to generate a single terrain database from all three. These three files define parts of the ocean floor which are separate, and which have some space between them. The heights in these files is around -365m. osgdem creates flat (blank) geometry between the tiles, which is what I want, but the problem is that it creates this geometry at Z=0. So the terrain database looks like: (data)(no data)(data) ___Z = 0 | | | | __| |_ Z = -365 (viewed from the side) Are there any ways to fix this? I can think of two off the top of my head: * Translate all the terrain heights up by about 365 meters, so that everything is near Z=0, then generate the terrain, and at run-time translate it back down by 365 meters. * Use a fake tile of data that would encompass the whole terrain and would be at about -365 meters everywhere, and then the three data files I have would be additional data (higher-res overlays, as I have seen used in some terrain database). Are there any other options? I think the second option is better, but I would appreciate others' points of view on this. Thanks, J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
Hi Robert, Ideally should have data throughout your model to define all the heights you require, if you have holes then all you can come if with is an acceptable fudge for what this missing data might be. I know, I know... :-) I work with what our client provided, so I have to fill in the gaps myself. Perhaps the easist way to provide this fudge would be to create a single dummy DEM that covers the entire region and matches the elevations of the tiles you have. The actual data would then act is a high res inserts to this base level DEM. Yes, that was the second option I mentioned. Any hints as to how to do that? I have the FWTools distribution, which includes all gdal binaries, but if there's another tool that I could use, please point me in the right direction. Ideally, I would like the base terrain to conform to the inserts at the edges of said inserts, instead of having steps around the inserts... So the tool used would probably need to interpolate between the tiles. I tried using gdal_merge.py, currently waiting for the terrain to generate from the result of that (I can't use --TERRAIN, so it takes a while)... But it doesn't interpolate, it just puts either NODATA or a value you specify. Anyways, thanks for confirming my intuition. J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
On Thu, Jul 10, 2008 at 3:43 PM, Jean-Sébastien Guay [EMAIL PROTECTED] wrote: Any hints as to how to do that? I have never tried to create a DEM so can't help you here. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
Hi all, I have never tried to create a DEM so can't help you here. Anybody else? I'm sure I'm not the first one to want to do this, I just can't find something in gdal that does this so I'd appreciate being pointed in the right direction. Thanks in advance, J-S -- __ Jean-Sebastien Guay[EMAIL PROTECTED] http://www.cm-labs.com/ http://whitestar02.webhop.org/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VPB generating terrain for multiple data files
Jean-Sébastien Guay writes: Ideally should have data throughout your model to define all the heights you require, if you have holes then all you can come if with is an acceptable fudge for what this missing data might be. I know, I know... :-) I work with what our client provided, so I have to fill in the gaps myself. The way we do this in ossimPlanet is to use a global dem with highres inserts. We use srtm30_plus for this This older thread might help http://osgcvs.no-ip.com/osgarchiver/archives/December2004/0756.html Norman ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
