[postgis-users] A question on ST_RemEdgeModFace usability

[Sandro Santilli]

On Thu, Apr 12, 2012 at 10:43:47PM +0200, Andrea Peri wrote:

> Perhaps
> I could try this option ?
> Always with a TopoGeometry applied over it.
> 
> Topogeometry T1 on Face F1.
> 
> First change edge from this
> (moving the external edge of F2 and moving also the edge "e")
> 
> I guess the ST_ChangeEdge should allow me move the edge "e".
> 
>  +----+----+      +---------+-----+
>  |    |    |      |         |     |
>  | F1 e F2 |  =>  |    F1   e  F2 |
>  |    |    |      |         |     |
>  +----+----+      +---------+-----+

There's no way to "move an edge".
You can change the edge shape but start and end nodes
must stay the same.

> and after this remove the external edge of F2
> 
>     +---------+
>     |         |
>  => |    F1   e
>     |         |
>     +---------+
> 
> Is this allowed ?

If your goal is to turn T1 onto taking the whole space of F1 and F2
you should just add F2 to the definition of T1.
No need to drop any edge.

--strk;

  ,------o-. 
  |   __/  |    Delivering high quality PostGIS 2.0 !
  |  / 2.0 |    http://strk.keybit.net - http://vizzuality.com
  `-o------'