Hi Artem,

I've done a ST_IsValid() on my data is it comes back true.  Unfortunately I
don't know how I can check the ring orientation as per Rob's message but I
assumed the loader I'm using would not put anything invalid into PostGIS .
Below is the ST_AsText() of a single object. It's a multpolygon representing
a four-way road junction, with three holes (rounded triangles) for traffic
islands. When rendered with Mapnik, these holes are filled by the
<PolygonSymbolizer>.

Thanks for any feedback you can give me.

/Bud

"MULTIPOLYGON(((-393802.666304504 6571763.54720833,-393804.624673949
6571763.93321782,-393805.186158372 6571764.04798212,-393808.279511376
6571764.61584465,-393811.514192577 6571765.10172054,-393814.91128285
6571765.26804909,-393815.224844811 6571765.34055503,-393815.549766038
6571765.33378385,-393815.707365817 6571765.40953994,-393816.178527578
6571765.55780195,-393816.743942504 6571765.86218053,-393816.903179908
6571766.01694288,-393817.060779713 6571766.09269896,-393817.142036024
6571766.24908641,-393817.299635836 6571766.32484248,-393817.462148476
6571766.6376174,-393818.042302052 6571767.6530525,-393818.125196013
6571767.88844626,-393818.206452363 6571768.04483374,-393818.211365212
6571768.28185262,-393818.292621567 6571768.4382401,-393818.313910594
6571769.46532203,-393817.950206761 6571770.7375486,-393816.563130079
6571772.82150674,-393812.706959492 6571776.85389125,-393809.706837836
6571780.15707204,-393806.952241224 6571782.75957972,-393814.803808382
6571791.44850876,-393817.245050519 6571790.03813533,-393820.765360833
6571788.62108167,-393824.439994835 6571787.12176992,-393828.126091502
6571786.17550204,-393831.649778873 6571785.54877981,-393835.59591696
6571785.22941376,-393839.532333489 6571785.06832961,-393843.244633197
6571785.38615834,-393848.771688958 6571786.06136259,-393849.346499925
6571786.19165453,-393851.42414182 6571786.68582474,-393853.371159961
6571787.15110094,-393855.671714895 6571787.73547243,-393858.68229187
6571788.70024621,-393862.896773183 6571790.0351265,-393866.709990415
6571791.45741017,-393876.694563661 6571776.34221567,-393869.699201671
6571771.95112088,-393868.500106743 6571771.18571264,-393867.299373949
6571770.341298,-393865.937764947 6571769.26311553,-393864.57451824
6571768.10592669,-393863.365596053 6571766.86648043,-393862.077055113
6571765.54965344,-393860.530108394 6571763.68493023,-393859.148845299
6571761.65867279,-393857.926820925 6571759.78717703,-393856.950098991
6571757.83152798,-393855.799504795 6571755.64238261,-393854.88121616
6571753.36935516,-393854.7137885 6571752.81956309,-393854.191957014
6571750.85443351,-393853.835808556 6571748.72777038,-393853.7168789
6571746.7542436,-393853.677568143 6571744.85809791,-393853.707720955
6571742.54949581,-393853.897438934 6571740.41145669,-393854.666785744
6571734.2460981,-393832.936724013 6571728.45484903,-393832.467084534
6571729.63442977,-393831.788291112 6571731.38745823,-393830.963257179
6571732.98545467,-393829.519394583 6571735.46578963,-393827.823678732
6571737.71425352,-393827.441963056 6571738.1174095,-393825.905378535
6571739.88831633,-393824.196559479 6571741.50473237,-393823.89118666
6571741.82725716,-393822.096197697 6571743.05026803,-393820.312567387
6571744.19400177,-393818.357030255 6571745.19904541,-393817.892420046
6571745.36680819,-393815.930004469 6571746.04002584,-393813.896054196
6571746.39857293,-393813.026904857 6571746.49572552,-393810.819083058
6571746.62077455,-393808.528367712 6571746.51042973,-393807.615315307
6571746.37137598,-393802.666304504 6571763.54720833),(-393835.870545371
6571775.89690605,-393831.649419379 6571773.61366697,-393830.497821986
6571775.13943702,-393828.561603924 6571777.07676211,-393832.255884393
6571776.52552543,-393835.870545371 6571775.89690605),(-393833.54745419
6571747.25367252,-393833.142915029 6571747.18306355,-393829.817786693
6571749.86069165,-393827.634529819 6571751.17083712,-393822.178022229
6571754.52520537,-393821.953905145 6571755.0041178,-393822.040074382
6571755.39752351,-393825.942713586 6571757.37123865,-393828.569921852
6571758.66017083,-393830.159819362 6571755.07022134,-393832.870297352
6571749.08571092,-393833.55564297 6571747.64870299,-393833.54745419
6571747.25367252),(-393854.496261603 6571773.05843329,-393853.035379289
6571770.95479167,-393851.645927093 6571768.53349974,-393850.090686016
6571765.64142152,-393848.613427097 6571762.7477186,-393846.441998211
6571757.10207359,-393845.666570943 6571754.19374467,-393845.053551495
6571750.96587058,-393843.286407228 6571753.53199179,-393841.327796707
6571757.52482976,-393837.917235957 6571764.23530382,-393840.441783715
6571765.58960528,-393843.413793908 6571767.20331721,-393849.160571841
6571770.32419342,-393854.187612909 6571773.22294777,-393854.496261603
6571773.05843329)))"

On Mon, Sep 6, 2010 at 9:57 AM, Artem Pavlenko <[email protected]> wrote:

> Hi Buddy,
>
> Mapnik should handle internal loops (holes) without any issues.
> Could you run ST_IsValid on that polygon ?  Also, you can post WKT
> here and I'll have a loook.
>
> Regards,
> Artem
>
> On 6 September 2010 09:31, Buddy Mash <[email protected]> wrote:
> > Hi,
> >
> > I'm new to Mapnik having taken over a project from a colleague who has
> left
> > our firm. I'm picking things up OK and have been successfully editing the
> > Mapnik XML for our maps.
> >
> > I have just hit my first technical issue with Mapnik. When rendering a
> > region with donut holes in it, the holes are ignored and the complete
> area
> > is filled by a a <PolygonSymbolzer>. I've checked the data in the PostGIS
> > database and using ST_NumInteriorRings does still return the current
> number
> > of interior rings/donut holes. Any ideas on what's happening? A Mapnik
> bug
> > or something wrong with the data?
> >
> > Cheers,
> > Bud
> >
> > _______________________________________________
> > Mapnik-users mailing list
> > [email protected]
> > https://lists.berlios.de/mailman/listinfo/mapnik-users
> >
> >
>
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