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<p>Hi Javier,<br>
</p>
<div class="moz-cite-prefix">Le 10/01/2022 à 00:30, Javier Jimenez
Shaw a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:CADRrdKvMqL_D8V9vyOg=oTn3WrygQq2a-uh6OWf6pBse-rueWQ@mail.gmail.com">
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<div>Hi</div>
<div><br>
</div>
<div>I want to transform coordinates from CRS A to CRS B in
C/C++ with PROJ 8.2.0<br>
</div>
<div>Usually A and/or B are geographic 3D or compound with the
geoid file included in PROJ-data. So far so good.<br>
</div>
<div><br>
</div>
<div>However sometimes one or both systems use a geoid file that
is not in PROJ-data. I would like to define de transformation
specifying the geoid file(s), and the interpolation reference
system(s). How is the best way to do it? Assume that the
transformation from geographic to vertical is not defined in
proj.db.<br>
</div>
</div>
</blockquote>
<p>Different potential ways:</p>
<p>- use a manually built PROJ pipeline</p>
<p>- use WKT string with BoundCRS (but I don't think you can control
the interpolation CRS that way)<br>
</p>
<p>- use proj_create_vertical_crs_ex()<br>
</p>
<p>- add new grid_transformation records in proj.db or an auxiliary
DB</p>
<p>Even<br>
</p>
<blockquote type="cite"
cite="mid:CADRrdKvMqL_D8V9vyOg=oTn3WrygQq2a-uh6OWf6pBse-rueWQ@mail.gmail.com">
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<div><br>
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<div>Thanks</div>
<div>Javier<br>
</div>
<div>
<div>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">.___ ._ ..._ .. . ._.
.___ .. __ . _. . __.. ... .... ._ .__<br>
Entre dos pensamientos racionales <br>
hay infinitos pensamientos irracionales.<br>
<br>
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<br>
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</blockquote>
<pre class="moz-signature" cols="72">--
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My software is free, but my time generally not.</pre>
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