Hi,<br><br>just some samples to start the question:<br><br>suppose to have 2 topogeometry T1 and T2 where<br>T1 = face1 (F1) + face2 (F2)<br><br>And T2 = face3 (F3)<br><br>and outside the universal-face<br><br>      ----------------<br>
    /          |       \  (universe Face)<br>    |          |       |<br>    |      F1  | F2    |<br>    |          |       |<br>    |          e1      e2<br>    |          |       |<br>     \----------------/<br>    /                 \<br>
    |                 |<br>    |        F3       |<br>    |                 |<br>    |                 |<br>    |                 |<br>     \---------------/<br><br>The edge e1 is invisible for the Topogeometry1 (T1)<br>so actually the postgis topology allow to remove it with the ST_RemEdgeModFace().<br>
And having so this new situation:<br><br>      ----------------<br>    /                 \<br>    |                 |<br>    |      F1         |<br>    |                 |<br>    |                 e2<br>    |                 |<br>
     \----------------/<br>    /                 \<br>    |                 |<br>    |        F3       |<br>    |                 |<br>    |                 |<br>    |                 |<br>     \---------------/<br><br>where the TopoGeometry are:<br>
T1 = face1 (F1)<br>T2 = face3 (F3)<br><br>But if the edge I need to remove is the e2 edge the situation change:<br>please notice the edge e2 has the universe-face on a side.<br><br>      ----------------<br>    /          |       \<br>
    |          |       |   (universe face)<br>    |      F1  | F2    |<br>    |          |       e2<br>    |         e1       |<br>    |          |       |<br>     \----------------/<br>    /                 \<br>    |                 |<br>
    |        F3       |<br>    |                 |<br>    |                 |<br>    |                 |<br>     \---------------/<br><br>I agree the new situation should be this:<br><br>      ----------<br>    /          |<br>
    |          |          (universe face)<br>    |      F1  |     <br>    |          |       <br>    |         e1       <br>    |          |       <br>     \----------------<br>    /                 \<br>    |                 |<br>
    |        F3       |<br>    |                 |<br>    |                 |<br>    |                 |<br>     \---------------/<br><br>But as I understand this seem to be impossible to have because actually postgis topology don't allow to remove the edge e2.<br>
Becasue this mean change the form of the topogeometry T1<br><br>Please notice this is don't compliant with the ISO specs, but in effect the ISO specs don't know the TopoGeometry layer.<br> <br>I guess this use-case was not compliant with iso specs, but it is again a perhaps unfrequent case.<br>
<br>But there also this other case more frequetnly that could reduce many the useful of ST_RemEdgeModFace:<br><br>Starting from this situation:<br><br><br>      ----------------<br>    /          |       \  (universe Face)<br>
    |          |       |<br>    |          |       |<br>    |----------|-------|<br>    |    |     |       |<br>    | F5 e4 F4 e5      |<br>    |    |     |       |<br>    |----------|       |<br>    |          |       |<br>
    |      F1  | F2    |<br>    |          |       |<br>    |         e1       |<br>    |          |       |<br>     \---------------/<br>    /                 \<br>    |                 |<br>    |        F3       |<br>    |                 |<br>
    |                 |<br>    |                 |<br>     \---------------/<br><br>where <br>Topogeometry T3 = face4 (F4)<br><br>I could need to remove the edge e4, where the e4 is and edge that don't have the universe-face on any side.<br>
<br>Is the edge e4 removable with the ST_RemEdgeModFace and have this result <br><br><br>      ----------------<br>    /          |       \  (universe Face)<br>    |          |       |<br>    |          |       |<br>    |----------|-------|<br>
    |          |       |<br>    | F4       e5      |<br>    |          |       |<br>    |----------|       |<br>    |          |       |<br>    |      F1  | F2    |<br>    |          |       |<br>    |         e1       |<br>
    |          |       |<br>     \---------------/<br>    /                 \<br>    |                 |<br>    |        F3       |<br>    |                 |<br>    |                 |<br>    |                 |<br>     \---------------/<br>
<br>Is this allowed ?<br><br>Thanks,<br><br>Andrea Peri<br><br clear="all"><br>-- <br>-----------------<br>Andrea Peri<br>. . . . . . . . . <br>qwerty àèìòù<br>-----------------<br><br>