[Qgis-developer] Transformation using NTv2 grids

[Giovanni Manghi]

Hi,


> obviously the best choice, thanks Juergen.


of course this is the best choice, but especially in case of grids not
available as part of proj (maybe because the institution that does
create the grid has no interest or idea about proj) the use from a
user point of view is a pain in the a**, as already commented.

the plugin as it was created solves a common, difficult, problem for
the users in the most simple and transparent way: as every grid is
about a specific A <-> B transformation, then the involved coordinate
reference systems are hardcoded with the correct and best definition
for that specific grid/transformation. This way the user does not have
to worry about anything, it just need to know in what CRS are the
input layers. Of course the plugin is not for on the fly
transformations, but rather to create copies of layers in new CRSs,
with the best possible precision.

> re: the Portuguese plugin: why not publishing in the officail repo, as a
> first step?

we choose a safe approach: let the local users test it extensively.
And then our feedback was that most of them wanted a localized plugin.
At that time localization in processing was not yet available, so we
kept the plugin in a separate repo. This could change, because now
processing supports localization (right?) and maybe because others are
intersted in expading it to support grids/transformations for other
countries.



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Giovanni Manghi
http://www.naturalgis.pt/
* QGIS Desktop development
* WebGIS development
* QGIS and PostGIS Training
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