Robert Osfield writes: > > Hi Looch, > > On 12/19/06, I-Gualano, Luciano <[EMAIL PROTECTED]> wrote: > > Thanks for everyones help and quick responses. I can create the 8 > > geotiff files (approx 1.8Gb each). > > > > Just some more questions. > > > > 1) To create the elevation file using topography (2km) png > file is the > > following command correct gdal_translate > > srtm_ramp2.world.21600x10800.png topo.tif gdaladdo -r > average topo.tif > > 2 4 8 16 32 64 128 256
Those commands looks good but this will not have any georeferencing Probably easiest to do this using the GDAL VRT mechanism http://www.gdal.org/gdal_vrttut.html # following .vrt untested but should be OK ## srtm_ramp2.world.21600x10800.vrt <VRTDataset rasterXSize=\"21600\" rasterYSize=\"1080\"> <SRS>WGS84</SRS>\n' <GeoTransform>-180.0,0.016666666666666,0,90.0,0,-0.016666666666666</GeoTrans form> <VRTRasterBand dataType=\"Byte\" band=0 subClass="VRTRawRasterBand"> <SourceFilename relativetoVRT=\"1\">srtm_ramp2.world.21600x10800.png</SourceFilename> <ImageOffset>0</ImageOffset> <PixelOffset>2</PixelOffset> <LineOffset>21600</LineOffset> </VRTRasterBand> </VRTDataset> # following using VRT above gdal_translate srtm_ramp2.world.21600x10800.vrt srtm_ramp2.world.21600x10800.tif gdaladdo -r average srtm_ramp2.world.21600x10800.tif 2 4 8 16 32 64 128 256 > > > > 2) To build the OSG earth output file (ive) using the 8 geotiff and > > elevation data file is the following command correct? > > osgdem --bluemarble-west -t A1.tif -t A2.tif -t B1.tif -t B2.tif > > --bluemarble-east -t C1.tif -t C2.tif -t D1.tif -t D2.tif > > --whole-globe -d topo.tif --geocentric -l 12 -o earth.ive > > The --bluemarble-west/east only applies to the next -t or -d, > so the -t A2.tif etc won't inherit this setting. However, > this isn't what you'd want anyway as you can't have A1 to B2 > all overlapping each other... What you'd need to do is > ensure that these .tif files all have the correct geospatial > coords assigned to them, if they do already then you want > need the --bluemarble-west as osgdem/osgTerrain can pick up > the settings directly from the file rather than having to assume it. The input files should now all have proper internal georeferencing that GDAL and OSG will pick up automagically Note these names correspond to the original NASA naming scheme http://telascience.sdsc.edu/tela_data/BM/bmng.pdf HTH Norman _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
