<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">For sure you can get a much less expensive result than the SFCGAL approach by using voronoi on a densified version of your geometry. It’s a few orders of magnitude faster that SFCGAL.<br><br><div id="AppleMailSignature"><strong style="font-size: 13pt; background-color: rgba(255, 255, 255, 0);">Stephen V. Mather </strong><div><span style="background-color: rgba(255, 255, 255, 0);">+1 (216) 339-6347 (Signal, Telegram, Cell, and WhatsApp)</span></div></div><div><br>On Jan 18, 2018, at 02:12, Regina Obe <<a href="mailto:lr@pcorp.us">lr@pcorp.us</a>> wrote:<br><br></div><blockquote type="cite"><div><span>Well it certainly takes longer than I care to wait and not cancellable.  But CPU on my end is not spiking.</span><br><span></span><br><span>But I'm running a 1.3 branch (dated in September 7, 2017), but unfortunately.</span><br><span></span><br><span>I know the 1.2.2 version had tons of issues with things including ST_StraightSkeleton, so I suspect ST_StraightSkeleton is pretty unusable in the 1.2 versions.</span><br><span></span><br><span>The rest of issues I see are with the output</span><br><span></span><br><span><a href="https://github.com/Oslandia/SFCGAL/issues">https://github.com/Oslandia/SFCGAL/issues</a></span><br><span></span><br><span>I'm going to try to build against latests head (my last head build seems to have failed).</span><br><span></span><br><span>I thought Stephen Mathers had written one that doesn't require SFCGAL, though I could be mistaken.</span><br><span></span><br><span>Steve - if you are on list can you respond?</span><br><span></span><br><span>Thanks,</span><br><span>Regina</span><br><span></span><br><span></span><br><span></span><br><span></span><br><span>-----Original Message-----</span><br><span>From: postgis-devel [<a href="mailto:postgis-devel-bounces@lists.osgeo.org">mailto:postgis-devel-bounces@lists.osgeo.org</a>] On Behalf Of Stephen Woodbridge</span><br><span>Sent: Wednesday, January 17, 2018 2:47 PM</span><br><span>To: PostGIS Development Discussion <<a href="mailto:postgis-devel@lists.osgeo.org">postgis-devel@lists.osgeo.org</a>></span><br><span>Subject: [postgis-devel] Problem in st_StriaghtSkeleton - Hangs!</span><br><span></span><br><span>Hi all,</span><br><span></span><br><span>I have run into a problem using st_StraightSkelton() where it appears to hang at 100 cpu. Maybe an endless loop?</span><br><span></span><br><span>select st_straightskeleton('POLYGON((256 760,518 760,518 630,674 630,674</span><br><span>239,673 239,127 239,127 240,126 240,126 513,127 513,127 514,126 514,126</span><br><span>630,255 630,256 630,256 760),(128 629,128 423,270 423,270 422,271</span><br><span>422,271 240,672 240,672 629,128 629),(258 759,258 631,516 631,516</span><br><span>759,258 759),(128 421,128 240,269 240,269 421,128 421))'::geometry);</span><br><span></span><br><span>POSTGIS="2.3.3 r15473" GEOS="3.5.1-CAPI-1.9.1 r4246" SFCGAL="1.2.2" </span><br><span>PROJ="Rel. 4.9.2, 08 September 2015" GDAL="GDAL 1.11.3, released 2015/09/16" LIBXML="2.9.3" LIBJSON="0.11.99" RASTER</span><br><span></span><br><span>Can anyone reproduce this?</span><br><span>Any idea how to work around it?</span><br><span></span><br><span>Is there a non-CGAL version of skeleton?</span><br><span></span><br><span>Thanks,</span><br><span>   -Steve</span><br><span></span><br><span>---</span><br><span>This email has been checked for viruses by Avast antivirus software.</span><br><span><a href="https://www.avast.com/antivirus">https://www.avast.com/antivirus</a></span><br><span></span><br><span>_______________________________________________</span><br><span>postgis-devel mailing list</span><br><span><a href="mailto:postgis-devel@lists.osgeo.org">postgis-devel@lists.osgeo.org</a></span><br><span><a href="https://lists.osgeo.org/mailman/listinfo/postgis-devel">https://lists.osgeo.org/mailman/listinfo/postgis-devel</a></span><br><span></span><br><span>_______________________________________________</span><br><span>postgis-devel mailing list</span><br><span><a href="mailto:postgis-devel@lists.osgeo.org">postgis-devel@lists.osgeo.org</a></span><br><span><a href="https://lists.osgeo.org/mailman/listinfo/postgis-devel">https://lists.osgeo.org/mailman/listinfo/postgis-devel</a></span></div></blockquote></body></html>