ERROR: lwcollection_construct: mixed dimension geometries: 2/0

[ognjenantonijevic]

Hi,

This is not a Martin issue per se, but rather a suggestion to add a setting to include a parameter which will be added to each ST_AsMVTGeom function call.

I've been experiencing issues when generating tiles for several layers. After googling a bit I found out this is a known issue with ST_AsMVTGeom, which is (reportedly) solved in some other tile servers by adding a ST_Force2D function inside the function call.

Error message:
ERROR: lwcollection_construct: mixed dimension geometries: 2/0

Relevant issues:
https://trac.osgeo.org/postgis/ticket/4690
CrunchyData/pg_tileserv#39
submarcos/django-vectortiles#57

The setting could be something like force_2d=true and it would influence the format of the ST_AsMVTGeom function call in file

martin/martin/src/pg/query_tables.rs

Line 198 in cce9d08

ST_AsMVTGeom(

[ognjenantonijevic]

Actually, it seems I've managed to go around this problem by turning off geometry clipping in settings.yaml. Leaving this here in case someone else has the same problem.

[CommanderStorm]

From the issue you mentioned:

ST_Force2D seems to fix this problem, but at a steep cost in time to generate MVTs

This seems like not such a nice tradeoff.. 🤔
If we support this this must be only on columns which actually need it and with a warning that this degrades performance.

I would like to push this down to the data generation level.
=> How do you generate the data? Having mixed dimension seems kind of unnessesary

[CommanderStorm]

(moved to a discussion since I am not quite sure what is the right approach here)