On 06/11/13 23:48, Justin Deoliveira wrote: > On Wed, Nov 6, 2013 at 6:24 AM, Andrea Aime > <andrea.a...@geo-solutions.it <mailto:andrea.a...@geo-solutions.it>> wrote > Hi, > when dealing with 3 dimensional data we genate GML that has the > srsDimension attribute > at the geometry level. > It's a good place, it avoid repeating the attribute in all posLists > around the code, however, > the GML specification is not clear about how it is supposed to be > handled, the spec > says that srsName is inherited by the contained elements, but does > not say anything about > srsDimension. > Turns out there is software around (NTS) that is not able to deal > with srsDimension at the > geometry level, and works only if it is specified at the posList > level instead. > How do you feel about having srsDimension be specified also at the > posList level?
-1. Pages 58-59 of the GML 3.2.1 spec (OGC 07-036) note that it is expected that SRS attributes "will be specified at the direct position level only in rare cases". It seems to me that srsDimension goes hand-in-hand with srsName. Furthermore (p56): "The optional attribute srsDimension is the number of coordinate values in a position. This dimension is derived from the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted." In my view we should discourage the practice of putting srsDimension on pos/posList; I think that if NTS does not accept srsDimension on geometries then it is broken. Kind regards, -- Ben Caradoc-Davies <ben.caradoc-dav...@csiro.au> Software Engineer CSIRO Earth Science and Resource Engineering Australian Resources Research Centre ------------------------------------------------------------------------------ November Webinars for C, C++, Fortran Developers Accelerate application performance with scalable programming models. Explore techniques for threading, error checking, porting, and tuning. Get the most from the latest Intel processors and coprocessors. See abstracts and register http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk _______________________________________________ GeoTools-Devel mailing list GeoTools-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
