[postgis-devel] GeoJSON Precision

[Nicklas Avén]

Martin Davis <mtnclimb at gmail.com> skrev: (8 maj 2019 00:17:57 CEST)
>Something to consider is that simply truncating digits can cause
>topological invalidity.  So at a minimum there should be a warning
>about
>this possibility in the doc.
>
>Ideally this would be part of a wider review of how PostGIS handles
>precision.  A more general approach might provide metadata about
>coordinate
>precision (somewhere), in which case the output functions would just Do
>The
>Right Thing.


We started to collect some thoughts about those things some years ago

https://trac.osgeo.org/postgis/wiki/ToleranceDiscussion

I think this might also be connected to the idea of offering a precission aware serialization like twkb as an optional format in Postgis. For the accuracy aware user it would give both more compressed data and a more "true" representation of the real world data. Then the precission is built into the serialization as part of the compression.

I have also done tests including triangulation information into twkb (approx 3 bytes per triangle in overhead). That would give a very efficient format for clients to render in gpu? With still smaller size than todays serialization. 
That I think would boost qgis rendering quite a lot :).

/Nicklas

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