[gdal-dev] OGR 3D coordinates

[Frank Warmerdam]

Andrew T. Louis wrote:
> Hi all,
> Does the ogr2ogr tool handle composed WKT (datum + elevation=Z value)
> for CRS transformation?
> I tried with no success... 

Andrew,

Are you asking if GDAL/OGR supposed compound coordinate system
defining the Z axis in WKT?  The short answer is no.

> If it does, should the input coordinates only be 3D? Or will it ignore
> the Z value when transforming a 2D input?

The transform() method on OGRGeometries will assume a Z of zero before
calling the transformer which operates in 3D.  Reviewing the code quickly
it seems that in some cases (some types of geometry) the geometry may
be forced into 3D mode after the transform method.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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