Hi Alexandre, I can reproduce the problem you reported with version 3.3.0, could you please file a ticket on trac.osgeo.org/postgis with all the detail ? It sounds like a regression. Use component "Topology" please.
I confirm using 2D only works fine. Gory details: the problem likely lays in _lwt_MakeRingShell which was recently changed to NOT use GEOS but rather do things internally, to reduce overhead. The internal implementation is NOT dropping the Z as the geos implementation did. Your filing a ticket will greatly help :) --strk; On Fri, Aug 26, 2022 at 11:14:11AM +0000, Alexandre Silva wrote: > Hello, > > I'm having some trouble creating a 3D topology using totopogeom method, I > don't know if I'm not using the functions correctly or if there's indeed a > bug, so any help would be appreciated. > > I reduced the problem to an example with two lines. > The first line is added with no errors to the topology but the second one > throws this error "Corrupted topology: ring of edge -3 is geometrically > not-closed". > The second line intersects with the first one, but there's no vertex on the > intersection. > I found two workarounds but both of them have some disadvantages in my point > of view. > The first one was to add manually a vertex on the intersection (this involves > someone doing that work manually). > The other one was to add the start and end point of every line using > topogeo_addpoint before calling totopogeom (this involves remembering to do > this every time that I create a topology and I think it's redundant and > overhead for most cases). > > https://imgur.com/a/FgIVyMO - here is the visual of the data for the error > and non-error approach > https://pastebin.com/CR5dNYSZ - here is a script to emulate the error, with > the two workarounds commented > > Not having much knowledge of the c code base, just looking at the code > surrounding the error > (https://www.postgis.net/docs/doxygen/3.0/d6/d03/lwgeom__topo_8c_source.html), > my wild guess is that when it creates the ring of the newly closed area, and > as there is no vertex on the intersection so no snap made, the ring is closed > on 2D dimension but there is a 3D gap that makes the ring not geometrically > closed. My reasoning for this is that the same data with a 2D topology has no > errors and if I reverse the insertion order (there would be a node on the > intersection), it also works. I can also be completely wrong. > > This error was tested on docker image postgis/postgis:14-3.2-alpine with > postgis version: > POSTGIS="3.2.1 0" [EXTENSION] PGSQL="140" GEOS="3.10.2-CAPI-1.16.0" > PROJ="8.2.0" LIBXML="2.9.13" LIBJSON="0.15" LIBPROTOBUF="1.4.0" WAGYU="0.5.0 > (Internal)" TOPOLOGY > > There's no error in this version (also running in docker): > POSTGIS="3.0.1 ec2a9aa" [EXTENSION] PGSQL="120" GEOS="3.7.1-CAPI-1.11.1 > 27a5e771" SFCGAL="1.3.6" PROJ="Rel. 5.2.0, September 15th, 2018" GDAL="GDAL > 2.4.0, released 2018/12/14" LIBXML="2.9.4" LIBJSON="0.12.1" > LIBPROTOBUF="1.3.1" WAGYU="0.4.3 (Internal)" TOPOLOGY RASTER > > Thanks, > Alexandre Silva _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/postgis-users
