[QGIS-Developer] Storing topology information in a vector layer (format)?

[Stefan Keller]

Hi,

This is about processing either an area mesh (tesselation) layer. Area
meshes are topological structures and issue is that most spatial data
formats - other than TopoJSON and E00 - are non-topological.

This in means, that a data reader has to infer the topology from
geometry (which requires exponential computing time), and even worse,
that potentially there are topological errors (like gaps,
overlaps/slivers). The built-in "Topology Checker Plugin" of QGIS [1]
does the validation preprocessing step.

Are there any ideas to store topology in a polygon vector layer (e.g.
as array of features IDs to reference polygon neighbors), so a reader
(a PyQGIS function/extension) doesn't have to rebuild the topology
every time?

:Stefan

[1] https://docs.qgis.org/3.4/en/docs/user_manual/plugins/core_plugins/plugins_topology_checker.html