<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I am converting elevation data in Gtiff format to contours in KML format, but running into a usage problem when attempting to create 3D contours.<div><br class="webkit-block-placeholder"></div><div>I noted the discussion here about enabling correct 3D representation in Google Earth (This is a great addition):</div><div><a href="http://trac.osgeo.org/gdal/ticket/1570">http://trac.osgeo.org/gdal/ticket/1570</a></div><div>and the need to use driver specific name=value option for ogr2ogr of "-dsco AltitudeMode=absolute"<font class="Apple-style-span" face="Helvetica"> here:</font></div><div><a href="http://www.gdal.org/ogr/drv_kml.html">http://www.gdal.org/ogr/drv_kml.html</a></div><div><br class="webkit-block-placeholder"></div><div>When I attempt to use it with gdal_translate the utility simply returns the usage instructions. I'm guessing that either I am putting the flag in the wrong place or this option is not enabled in gdal_contour, even though I am able to successfully write KML with gdal_contour. </div><div><br class="webkit-block-placeholder"></div><div>I'm running GDAL 1.5.0b2 on mac os x. This works for me:</div><div><span class="Apple-style-span" style="font-family: Helvetica; ">gdal_contour -f KML -i 5.0 blakely.tif five_meter_contours.kml <span class="Apple-tab-span" style="white-space:pre"> </span>//Note: the -3d switch is left out intentionally since it does not seem to affect KML output</span></div><div><font class="Apple-style-span" face="Helvetica"><br class="webkit-block-placeholder"></font></div><div><font class="Apple-style-span" face="Helvetica"><br></font></div><div><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-family: 'Lucida Grande'; ">These do not:</span></font></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: 12.0px Helvetica">gdal_contour -f KML -i 5.0 blakely.tif five_meter_contours.kml -dsco AltitudeMode=absolute</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: 12.0px Helvetica">gdal_contour -f KML -dsco AltitudeMode=absolute -i 5.0 blakely.tif five_meter_contours.kml</font></div></div><div><br></div><div>Anyone have ideas of the problem? </div><div><br class="webkit-block-placeholder"></div><div>Regards,</div><div><br class="webkit-block-placeholder"></div><div>Dane</div><div><br class="webkit-block-placeholder"></div></body></html>