I generate vector tiles using data from Postgres DB and PostGIS function ST_AsMVTGeom. I'd like to take advantage of overzooming so that I can only create vector tiles say for Zoom Level 15, and then overzoom the tiles to Zoom Level 19/20. I noticed that in some cases for detailed building outlines/land parcels the joining points loose their topological consistency once rendered into the vector tile and overzoomed. Things improve if I tile cache for larger scale, but this means I need more tiles. Is there any way to basically generate better quality/accuracy vector tiles for smaller scale so they better overzoom? Are there any methods to prevent such gaps? Could this be a result of over-simplification by the internals of ST_AsMVTGeom where I basically loose some points which causes the lines 'too straight' ?

Gaps in lines at L15

Ideally above should look like this after overzooming, but I could only achieve this after tile caching at Zoom Level 17:

enter image description here


1 Answer 1


After a bit of digging it looks like this is fixed/improved in PostGIS 3.2.0 (I was on 3.1.1). According this release note:


#4149, ST_AsMVTGeom now preserves more of original geometry's details at scale close to target extent.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.