Hi Linh, First of all I am a newbie like you :) If I give you wrong information, forgive me!
ÜMİT UZUN ________________________________ > Date: Wed, 13 Feb 2008 14:30:51 -0800 > From: [EMAIL PROTECTED] > To: [email protected] > Subject: Re: [osg-users] how to read GeoTIFF files using osgdem? > > Hi Umit, > ümit uzun wrote: > > Hi Linh, > > 1. Reply : if you use geotiff image (which meaning georeferenced tiff) you > have to use like this command : > osgdem -t sample.tif -d sample.tif -l 2 -v 0.08 -o result.ive -a result.osga > > > > I thought the GeoTIFF would have the scaling info embeded in it since it > knows the x and y spacings, I thought > it would know the height as well? But I guess I will have to ask them for > what the scaling is then because usually > I wouldn't know what it is. Yes you are right. GeoTiff has a scaling in it. But sometimes especially you try to create your terrain using only your texturing geotiff images you have to use -v parametres. For example you download a texture image which name is sample.tif. And you will not use a elevation data like dem or tiff formatted. Your choice is only this command : " osgdem -t sample.tif -d sample.tif -o sample.ive -a sample.osga -l 2 -v 0.08 " if you type this command your terrain will be created. ı attech a osgdem.tar.gz folder. You will find 3 files by downloading from http://www.fileden.com/files/2007/9/10/1423182/osgdem.tar.gz I create a sample.osga with using a sample.tif images by given command which was typed above. You can look at this terrain with osgviewer. In osgdem.tar.gz you find a tile-sdds.sh shell. you can use this shell for creating a terrain. You only need to NED elevation tiff formatted image and tiff formatted texturing image to use. You can find the command usage in this shell script. To get these images you can look at http://seamless.usgs.gov/ site. > > In this command you can change the -v parameters value between 1.0 <= -v <= > 0.0 I think you would know why we use -l parameteres and value ranges. > To get geotiff image you can use; > http://geoengine.nga.mil/geospatial/SW_TOOLS/NIMAMUSE/webinter/rast_roam.html > or http://seamless.usgs.gov/ > And I think you only want to create your terrain you should look at > http://www.palomino3d.org/pal/openscenegraph/ site. > > But I can't understand your second question. If you want to make your terrain > visible when you run "osgviewer sample.osga" you will be seeing when you > create your terrain by first question's reply. > > > > I guess maybe the terrain they gave me has a problem because when I ran it > like you suggested > it seg fault when I use -t option on the tif file. It might be but try another step to step. > > Do you know if osgdem actually look at any of the .prj, .aux, .rrd at all or > is it only looking > at the .tif file? > > Also, do you know if we have two GeoTIFFs of one big patch (but low > resolution) and one smaller patch > (but high res) of the same area, we can use osgdem to generate an osga DEM > file with high res for the area > where we have high res and low res for area we have low res, eg using: > > osgdem -l 8 -d DEM_1m_landArea100x100m.tif -d DEM_10m_landArea4000x4000m.tif > -o test.ive -a test.osga > Yes I understand you. You should look at LOD (Level of Detail) method. osgviewer supporting this feature automatically. and you can't use different resolution elevation images in same terrain. You should use same range of resolution both of elevation and texture images. If you want to LOD processing by this way you don't need two different images. Choose high resolution and small patches and use them in osgdem -d 1.tif -d 2.tif . . . . . > Thank you Umit, > > Linh Where did you get the images(DEM_1m_landArea100x100m.tif) Ling ? > > If you have any problem you can ask Linh.Good Luck.. > > ÜMİT UZUN > > ---------------------------------------- > > > Date: Tue, 12 Feb 2008 18:42:38 -0800 > From: [EMAIL PROTECTED] > To: [email protected] > Subject: [osg-users] how to read GeoTIFF files using osgdem? > > Hi, > > this is my first time trying to use osgdem on a GeoTIFF file and I > wasn't successful in viewing the > generated osga file. The data (from > http://webgis.wr.usgs.gov/ftphirise/index.jsp) look like this: > > % ls DEM_1m_VictoriaCrater* > DEM_1m_VictoriaCrater.asc.gz DEM_1m_VictoriaCrater.rrd > DEM_1m_VictoriaCrater.aux DEM_1m_VictoriaCrater.tif > DEM_1m_VictoriaCrater.prj > > % cat DEM_1m_VictoriaCrater.prj > > PROJCS["Plate_Carree",GEOGCS["EQUIRECTANGULAR_CYLINDRICAL_MARS",DATUM["D_MARS",SPHEROID["MARS",3396190,0]],PRIMEM["Reference_Meridian",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Plate_Carree"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",180],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]] > > I then use osgdem command: > > % osgdem -l 2 -d DEM_1m_VictoriaCrater.tif -o test.ive -a test.osga > > % osgviewer test.osga > > But I didn't see anything when osgviewer first came up, but I know > something is there because when > I spin it, I see something spin by really fast. My question are: > > 1. Is the "-d DEM_1m_VictoriaCrater.tif" argument to osgdem all I need > for a GeoTIFF file? > > 2. Is there a way for osgviewer to put the object in the center so I can > see it or do > I have to ask the USGS to generate the GeoTIFF DEM that has the DEM > in the center so I can see? > > Thank you very much, > > Linh > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > > > _________________________________________________________________ > Yeni nesil Windows Live Servisleri’ne şimdi ulaşın! > http://get.live.com > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _________________________________________________________________ Yeni nesil Windows Live Servisleri’ne şimdi ulaşın! http://get.live.com _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
