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<DIV dir=ltr align=left><SPAN class=906331810-30102012><FONT size=2>Maybe ST_X,
ST_Y and ST_Z ?</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=906331810-30102012><FONT
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=906331810-30102012><FONT
size=2>Hugues.</FONT></SPAN></DIV>
<DIV> </DIV><BR>
<DIV dir=ltr lang=fr class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>De :</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>De la part de</B> Ed
Linde<BR><B>Envoyé :</B> mardi 30 octobre 2012 11:14<BR><B>À :</B>
PostGIS Users Discussion<BR><B>Objet :</B> Re: [postgis-users] Problem with
3D polygon intersection test<BR></FONT><BR></DIV>
<DIV></DIV>Hi Nicolas,<BR>Not quite sure what to make of the output from
ST_DumpPoints, how do I transform it to just raw x,y,z
coordinates?<BR><BR> select st_astext(geomtext) from small_tris where
id=0;<BR>
st_astext
<BR>-------------------------------------------------------<BR> POLYGON Z
((10 10 805,20 10 809,10 20 814,10 10 805))<BR>(1 row)<BR><BR>bounds=#
select id, st_dumpPoints( geomtext ) from small_tris where id=0;<BR> id
|
st_dumppoints
<BR>----+----------------------------------------------------------------------<BR>
0 |
("{1,1}",0101000080000000000000244000000000000024400000000000288940)<BR> 0
| ("{1,2}",0101000080000000000000344000000000000024400000000000488940)<BR>
0 |
("{1,3}",0101000080000000000000244000000000000034400000000000708940)<BR> 0
| ("{1,4}",0101000080000000000000244000000000000024400000000000288940)<BR>(4
rows)<BR><BR><BR>Thanks,Ed<BR><BR><BR>
<DIV class=gmail_quote>On Tue, Oct 30, 2012 at 11:05 AM, Ed Linde <SPAN
dir=ltr><<A href="mailto:edolinde@gmail.com"
target=_blank>edolinde@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Ok thanks!
<DIV class=HOEnZb>
<DIV class=h5><BR><BR>
<DIV class=gmail_quote>On Tue, Oct 30, 2012 at 11:04 AM, Nicolas Ribot <SPAN
dir=ltr><<A href="mailto:nicolas.ribot@gmail.com"
target=_blank>nicolas.ribot@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>st_dumpRings will return the rings (closed linestrings)
composing the polygon (exterior first, then interiors)
<DIV>and st_dumpPoints will return all the points forming the rings, in the
right order.</DIV><SPAN><FONT color=#888888>
<DIV><BR></DIV></FONT></SPAN>
<DIV><SPAN><FONT color=#888888>Nicolas</FONT></SPAN>
<DIV>
<DIV><BR><BR>
<DIV class=gmail_quote>On 30 October 2012 10:56, Ed Linde <SPAN
dir=ltr><<A href="mailto:edolinde@gmail.com"
target=_blank>edolinde@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Ok, for a polygon, is there a good postgis function that
can return the edges to me in the <BR>right sequence? Or at least the
points that constitute the polygon in the right order, so I
can<BR>generate the edges in a script?<BR><BR>Thanks,<BR>Ed
<DIV>
<DIV><BR><BR>
<DIV class=gmail_quote>On Tue, Oct 30, 2012 at 10:46 AM, Ed Linde <SPAN
dir=ltr><<A href="mailto:edolinde@gmail.com"
target=_blank>edolinde@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Ah drat! Ok then I have to basically do edge
intersection tests by myself.
<DIV>Ah well. bad news! :(
<DIV>
<DIV><BR><BR>
<DIV class=gmail_quote>On Tue, Oct 30, 2012 at 10:44 AM, Nicolas Ribot
<SPAN dir=ltr><<A href="mailto:nicolas.ribot@gmail.com"
target=_blank>nicolas.ribot@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Hi,
<DIV><BR></DIV>
<DIV>st_intersection is only suitable for 2D operations. Third
dimension is not taken into account.</DIV>
<DIV><BR></DIV>
<DIV>Nicolas </DIV>
<DIV><BR>
<DIV class=gmail_quote>
<DIV>
<DIV>On 30 October 2012 09:44, Ed Linde <SPAN dir=ltr><<A
href="mailto:edolinde@gmail.com"
target=_blank>edolinde@gmail.com</A>></SPAN> wrote:<BR></DIV></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>
<DIV>
<DIV>Hi All,<BR>Is there a simpler test I can do? I am quite sure
that I am probably not using the right <BR>function in my SQL, or
not doing the intersection test correctly. Is there any simpler
<BR>way to test this 3D intersection? Am waiting on the postgis
gurus to come along and<BR>give me some ideas, coz I am at my wits
ends on this one! :) The polygons look good<BR>to me when I
visualize them, but don't get how all triangles are found as
intersecting?<BR>Anyway will wait.<BR><BR>Cheers,<BR>Ed<BR><BR>
<DIV class=gmail_quote>On Tue, Oct 30, 2012 at 9:00 AM, Ed Linde
<SPAN dir=ltr><<A href="mailto:edolinde@gmail.com"
target=_blank>edolinde@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>Hi All,<BR>I am having some troubles getting the
<B>ST_Intersect</B> function to work with 3D polygons. <BR>I have
a table to hold triangles as polygons in
<B>"small_tris"</B><BR>Another table for holding the polygonal
faces of a 3D voronoi diagram in <B>"vfaces"</B><BR>So now I am
trying to do an intersection between the triangles and the voronoi
faces<BR>to get the triangles that intersect with the faces. And
it seems that *ALL* triangles <BR>are intersecting. I have
attached a PDF where I have plotted the triangles and the
<BR>voronoi cells. so the box around in red and blue with a major
face going through is <BR>the voronoi diagram. The Voronoi
partition in 3D is shown at the bottom too for clarity<BR>Can
someone please help and let me know what am I doing wrong
here?<BR>Is the select assuming something? So the polygons are
flat and the intersections <BR>should just be lines or points. I
am under some pressure to get this to work, so if<BR>anyone needs
more information to help, the please let me know! :)
<BR><BR>Cheers,<BR>Ed<BR><BR><B>-- TABLE SCHEMAS</B><BR>bounds=#
\d vfaces;<BR> Table
"public.vfaces"<BR> Column |
Type | Modifiers
<BR>----------+----------+-----------<BR> gen_id
| integer | <BR> geomtext | geometry | <BR><BR>bounds=#
\d small_tris;<BR> Table
"public.small_tris"<BR> Column |
Type | Modifiers
<BR>----------+----------+-----------<BR> id
| integer | not
null<BR> v0 |
integer | <BR> v1 |
integer | <BR> v2 |
integer | <BR> geomtext | geometry |
<BR>Indexes:<BR> "small_tris_pkey" PRIMARY KEY,
btree (id)<BR> "small_idx" gist
(geomtext)<BR><BR><BR><B><BR>-- TABLE CONTENT</B><BR>bounds=#
select id, st_astext( geomtext ) from small_tris;<BR> id
|
st_astext
<BR>----+-------------------------------------------------------<BR>
0 | POLYGON Z ((10 10 805,20 10 809,10 20 814,10 10
805))<BR> 1 | POLYGON Z ((10 20 814,20 10 809,20 20 819,10
20 814))<BR> 2 | POLYGON Z ((20 20 819,30 10 809,30 20
812,20 20 819))<BR> 3 | POLYGON Z ((30 10 809,20 20 819,20
10 809,30 10 809))<BR> 4 | POLYGON Z ((30 20 812,30 10
809,40 10 826,30 20 812))<BR> 5 | POLYGON Z ((20 20 819,30
20 812,20 30 827,20 20 819))<BR> 6 | POLYGON Z ((10 20
814,20 20 819,20 30 827,10 20 814))<BR> 7 | POLYGON Z ((10
40 805,10 30 814,20 30 827,10 40 805))<BR> 8 | POLYGON Z
((10 50 804,10 40 805,20 40 807,10 50 804))<BR> 9 | POLYGON
Z ((20 30 827,20 40 807,10 40 805,20 30 827))<BR> 10 |
POLYGON Z ((30 30 817,20 40 807,20 30 827,30 30 817))<BR> 11
| POLYGON Z ((30 40 816,20 50 809,20 40 807,30 40
816))<BR> 12 | POLYGON Z ((20 40 807,20 50 809,10 50 804,20
40 807))<BR> 13 | POLYGON Z ((10 30 814,10 20 814,20 30
827,10 30 814))<BR> 14 | POLYGON Z ((30 30 817,20 30 827,30
20 812,30 30 817))<BR> 15 | POLYGON Z ((30 20 812,40 20
823,30 30 817,30 20 812))<BR> 16 | POLYGON Z ((40 20 823,30
20 812,40 10 826,40 20 823))<BR> 17 | POLYGON Z ((40 20
823,40 10 826,50 10 803,40 20 823))<BR> 18 | POLYGON Z ((30
30 817,40 20 823,40 30 814,30 30 817))<BR> 19 | POLYGON Z
((40 20 823,50 20 808,40 30 814,40 20 823))<BR> 20 | POLYGON
Z ((50 20 808,40 20 823,50 10 803,50 20 808))<BR> 21 |
POLYGON Z ((40 30 814,50 20 808,50 30 816,40 30 814))<BR> 22
| POLYGON Z ((30 30 817,40 30 814,40 40 800,30 30
817))<BR> 23 | POLYGON Z ((30 40 816,40 40 800,30 50 813,30
40 816))<BR> 24 | POLYGON Z ((30 40 816,30 30 817,40 40
800,30 40 816))<BR> 25 | POLYGON Z ((30 50 813,40 40 800,40
50 817,30 50 813))<BR> 26 | POLYGON Z ((30 40 816,30 50
813,20 50 809,30 40 816))<BR> 27 | POLYGON Z ((50 40 821,40
50 817,40 40 800,50 40 821))<BR> 28 | POLYGON Z ((50 50
809,40 50 817,50 40 821,50 50 809))<BR> 29 | POLYGON Z ((50
40 821,40 40 800,50 30 816,50 40 821))<BR> 30 | POLYGON Z
((40 30 814,50 30 816,40 40 800,40 30 814))<BR> 31 | POLYGON
Z ((30 30 817,30 40 816,20 40 807,30 30 817))<BR>(32
rows)<BR><BR> select st_astext(geomtext) from
vfaces;<BR>
st_astext
<BR>-----------------------------------------------------------------------------------------------<BR> POLYGON
Z ((51 17.8 799,9 38.8 799,9 51 819.33333333333,19.4 51 828,51
35.2 828,51 17.8 799))<BR> POLYGON Z ((51 17.8 799,9 38.8
799,9 51 799,51 51 799,51 17.8 799))<BR> POLYGON Z ((51 35.2
828,19.4 51 828,51 51 828,51 35.2 828))<BR> POLYGON Z ((9 9
799,9 38.8 799,51 17.8 799,51 9 799,9 9 799))<BR> POLYGON Z
((51 17.8 799,9 38.8 799,9 51 819.33333333333,19.4 51 828,51 35.2
828,51 17.8 799))<BR> POLYGON Z ((9 9 828,9 51 828,19.4 51
828,51 35.2 828,51 9 828,9 9 828))<BR>(6 rows)<BR><BR><B
style="COLOR: rgb(51,102,255)">select distinct <A
href="http://a.id" target=_blank>a.id</A><BR>from small_tris a,
vfaces b<BR>where st_intersects (a.geomtext, b.geomtext)<BR>order
by <A href="http://a.id" target=_blank>a.id</A>;</B><BR> id
<BR>----<BR> 0<BR> 1<BR> 2<BR> 3<BR>
4<BR> 5<BR> 6<BR> 7<BR> 8<BR>
9<BR> 10<BR> 11<BR> 12<BR> 13<BR> 14<BR> 15<BR> 16<BR> 17<BR> 18<BR> 19<BR> 20<BR> 21<BR> 22<BR> 23<BR> 24<BR> 25<BR> 26<BR> 27<BR> 28<BR> 29<BR> 30<BR> 31<BR>(32
rows)<BR><BR><IMG alt=""
src=""><BR></BLOCKQUOTE></DIV><BR><BR></DIV></DIV>_______________________________________________<BR>postgis-users
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