Geotranformations in Runtime for .Net

[SalieghAziz]

Hi All,

You'll be seeing a lot of these questions from my in the coming weeks and months...

In our product where we using ArcObjects, we are able to allow for custom geotransformation to be configured, either using geocentric translations or the NTv2 grid type.

Is there an equivalent with the new arcgis runtime for .net? I can't seem to find an overload on the project method on the geometry engine class that would allow me to do this.

Thanks

[dotMorten_esri · Accepted solution]

Custom transformations are not supported at this time - a default one is picked for you (you might have to deploy the datum transformation files though depending on which spatial references you convert between).

It is on our roadmap to support.

[SalieghAziz]

Thanks for the reply.

Any idea what the timeline is on this?

[SachinKanaujia]

The API does not support it at this time but as an alternative you can use the Python Geoprocessing to accomplish this. We have done this in the Java environment and it works !!!!

[GIAdmin]

Is there still no solution for custom transformations? There is a folder in the Runtime installation directory which contains files that might have something to do with transformations (%runtimedir%\resources\pedata\gdaldata). So perhaps it is possible to apply some kind of workaround by changing these files?

[dotMorten_esri]

I'm not sure why you're seeing a gdaldata folder. Which version are you using?

Anyway, yes I believe you can put datum grid data in the PEData folder, and they could get picked up automatically if needed (you can find the PEData from the localserver install). However there's no APIs to specifically pick the correct transformation, so it'll do a best guess. Also not all datum transforms relies on the pedata.

We'll have this properly supported in v100.2 (just note that the undocumented PEData folder trick then might break at that point)

[GIAdmin]

Thanks for the reply. I'm using the 10.2.7 release.

I already found out that the default transformation of the spatial reference we are using (DHDN) is NTv2, which is a grid based transformation. But I think it is hard wired in the Runtime dll because I cannot find any reference of the datum grid file "Beta2007.gsb" in any of these files.

Nevertheless it might be possible to change the default transformation by changing the gcs.override.csv or pcs.override.csv file. But I have no idea how to accomplish this.

How will custom transformations be implemented in the 100.2 release? Will there be an overload of the project method of the GeometryEngine like in the Java SDK?

[MelitaKennedy]

The gdaldata folder files are used by raster only to support coordinate systems in rasters. They are not otherwise used.