Hi John, This sounds like a GDAL bug. Would it be possible for you to provide links to the problematic data. I'd guess the GDAL team might like to look at it as well.
Robert. Robert. On Thu, May 15, 2008 at 12:22 PM, John Vidar Larring <[EMAIL PROTECTED]> wrote: > Hi, > > Problem Summary: The calls to GDALRasterBand::RasterIO() in > vpd::SourceData::getInterpolatedValue() and > vpd::SourceData::readHeightField() returns no-data-values as 55537 instead > of the correct -9999 for gtopo30 data. > > VPB: revision 911 > OSG: revision 8321 > GDAL version 1.5.1 > > The following command line is used to create a simple globe (all DEM files > from gtopo30 are used): > > ./osgdemd -d in/gtopo30/E020N40.DEM [...snip...] -d in/gtopo30/W180S60.DEM > --bluemarble-east -t in/bluemarble/land_shallow_topo_east.tif > --bluemarble-west -t in/bluemarble/land_shallow_topo_west.tif --geocentric > --radius-equator 6378000 --radius-polar 6378000 -v 1.4 -l 6 -o > out/simple_globe.ive -a out/simple_globe.osga > > gdalinfo reports that the no-data-value for the DEM files are -9999: > > dhcp6(bin)% /usr/local/bin/gdalinfo -stats in/gtopo30/E020N40.DEM > [...snip...] > Min=-9999.000 Max=5825.000 > Minimum=-9999.000, Maximum=5825.000, Mean=-2347.600, StdDev=4873.500 > NoData Value=-9999 > > ... however, in the globe created by the command line above, the sea level > is high above ground. After some debugging, I made the following > observations: > > * SourceData.cpp - vpd::ValidValueOperator::ValidValueOperator() obtains the > correct no-data-value (-9990) though GDALRasterBand::GetNoDataValue() > * In vpd::SourceData::getInterpolatedValue() no-data-values are not clamped > to 0.0f (zero) because GDALRasterBand::RasterIO() returns no-data-values as > 55537.0f (the same happens in vpd::SourceData::readHeightField()) > > I highly temporary work-around hack was to alter the initialization of > vpb::ValidValueOperator::maxValue in line 38 in SourceData.cpp from > maxValue(FLT_MAX) to maxValue(55000.0f). Hence, the faulty no-data-values > are clamped to zero. > > I am totally new to OSG/VPB. Does anyone have an idea of how to make a > permanent fix for this problem? Is it just an incompatibility problem with > GDAL 1.5.1? or... > > Any advice would be greatly appreciated. > > Best regards, > John Larring > > > -- > 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 > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
