Question

Can the TINGenerator be used with geographic coordinate systems?


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In ArcGIS Pro a TIN can be created using the “Create TIN” tool. The usage notes of the tool say that it should be avoided to use a geographic coordinate system when creating the TIN, as the Delaunay triangulation might not work correctly when the coordinates are in angular units.

The “TINGenerator” transformer in FME does not provide such a usage note in the documentation. Does this mean that the “TINGenerator” transformer can create a TIN without problems when the input dataset is in a geographic coordinate system or is it also recommended here to reproject the input data to a projected coordinate system first?


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I’d give it a go and see what it produces. You can then do a comparison between that and the output from a projected system and see if it causes any problems

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Thank you for your answer @hkingsbury.

In general, using the TINGenerator with a geographic system did not produce any error messages.

I did a comparison, but it’s difficult for me to say, if both the TIN in the geographic system and the TIN in the projected system are identical.

First I created a TIN from a raster file that is in a geographic system. Then I projected the raster file to a projected system and created a TIN from the projected raster file.

However, visualising the TIN in the geographic system is not possible with the Data Inspector, for visualising in 3D I need to project the TIN to a projected system.

When I compare both TINs in 3D, they look similar, but there are slight differences. But I’m not sure if these differences could also be caused by the projections.

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