[gdal-dev] VRT file from NetCDF

[Even Rouault]

Selon Yves Jacolin <yjacolin at free.fr>:

> Hello,
>
> Etienne asked some question offlist so I investigate.
>
> gdal create relatif path by default (I don't see a flag to change this).
> MapServer and QGIS don't like this.

MapServer and QGIS don't even know the content of the VRT, so the problem is
more complex than that.

If you pass a relative path to gdalbuildvrt or gdal_translate -of VRT, a
relative path will be written. In which case the VRT driver should be able to
recompute the full path given the location of the .vrt.
On the contrary, if you pass an absolute path, it will be store as absolute.

The issue here is likely with netCDF subdatasets, where the connexion string is
not a file, but something like "netCDF:xxxx:a_filename", that the VRT driver
cannot interpret. In that case, the resolution of relative filenames will not
work. So I'd suggest you to use "netCDF:xxx:full_filename" to avoid those
issues. Or you must be sure that the current directory of MapServer and QGIS is
the directory of the .VRT, but you cannot always guarantee this.

>
> After changing relatif path to absolute path both are working correctly.
>
> Thanks,