It seems like this could be addressed by overloading the function so that whether the function builds tunnels and bridges is an option.
Steve Stephen Mather Geographic Information Systems (GIS) Manager (216) 635-3243 s...@clevelandmetroparks.com clevelandmetroparks.com -----Original Message----- From: Havard Tveite [mailto:havard.tve...@umb.no] Sent: Thursday, March 15, 2012 4:14 AM To: s...@clevelandmetroparks.com; PostGIS Users Discussion Subject: Re: [postgis-users] 3D geometries Hi, For "ST_SetMFromRaster(geom, rast)", I think it would be better to only add the Z/M value to the points of the input geometry. Those that want to do something like ST_Densify should do that as a separate preprocessing step. This would give the user more control of the process (the user may want tunnels and bridges). Håvard On 3/13/2012 7:47 PM, Stephen V. Mather wrote: > Hi Pierre, > > I could try my hand at this as a PL/pgSQL function. Can't help with the > C++... :) > > I'm thinking ST_Densify ala Paul deriving the densification from the cell > size of the input raster, then use st_dumppoints and st_intersects, and then > reconstruct to 3D line (or am I thinking too low level to be efficient). > > Best, > Steve > > > Stephen Mather > Geographic Information Systems (GIS) Manager > (216) 635-3243 > s...@clevelandmetroparks.com > clevelandmetroparks.com > > > > > > -----Original Message----- > From: Pierre Racine [mailto:pierre.rac...@sbf.ulaval.ca] > Sent: Tuesday, March 13, 2012 2:22 PM > To: s...@clevelandmetroparks.com; PostGIS Users Discussion > Subject: RE: [postgis-users] 3D geometries > > Hi Stephen, > > It would certainly be very nice to have a generic function doing it: > > SELECT ST_SetMFromRaster(geom, rast) geom > FROM mylines, myrast > WHERE ST_Intersects(geom, rast) > > Pierre > >> -----Original Message----- >> From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- >> boun...@postgis.refractions.net] On Behalf Of Stephen V. Mather >> Sent: Tuesday, March 13, 2012 1:43 PM >> To: postgis-users@postgis.refractions.net >> Subject: [postgis-users] 3D geometries >> >> Hi All, >> >> Any special considerations for turning a 2D multi-line > geometry into a >> 3D geometry using a DEM as a RASTER within PostGIS? Has anyone played in >> this arena? >> >> >> >> Thanks, >> Steve >> >> >> >> http://www.clemetparks.com/images/esig/cmp-ms-90x122.pngStephen Mather >> Geographic Information Systems (GIS) Manager >> (216) 635-3243 >> >> s...@clevelandmetroparks.com >> clevelandmetroparks.com<http://www.clemetparks.com/> _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
