3D operations (Re: [geos-devel] C API coordinate sequence dimensions)

[Mark Cave-Ayland]

On Tue, 2009-01-13 at 11:08 -0700, Sean Gillies wrote:

> "Smurf code"? Smurfs are good, if I remember my Saturday morning  
> cartoons :)
> 
> It would probably take me much longer to grep and read through the  
> code base to find which functions are 3D and document them in the wiki  
> than it would take the authors ... can I do anything to entice them to  
> document the 3D functions?
> 
> Sean

Bear in mind that even though some functions claim to support 3D, they
may actually be broken. We currently have an issue in PostGIS with
BuildArea returning an invalid polygon here due to an incorrect Z
coordinate:

http://postgis.refractions.net/pipermail/postgis-devel/2009-January/004571.html

Can anyone with more experience with BuildArea (like Martin!) comment on
whether this is a GEOS bug or simply a problem with behaviour > 2
dimensions being undefined?


ATB,

Mark.