Noobie question here:
I am trying to understand WKT so I can build my own polygons from GPS
points for entry by SGL commands. In reading the OGC specification
http://portal.opengeospatial.org/files/?artifact_id=18241
I thought I understood it to say that interior rings should have a
clockwise orientation,
"6.1.11.1 Description
A Polygon is a planar Surface defined by 1 exterior boundary and 0 or
more interior boundaries. Each interior
boundary defines a hole in the Polygon. A Triangle is a polygon with 3
distinct, non-collinear vertices and no
interior boundary.
The exterior boundary LinearRing defines the “top” of the surface which
is the side of the surface from which the
exterior boundary appears to traverse the boundary in a counter
clockwise direction. The interior LinearRings will
have the opposite orientation, and appear as clockwise when viewed from
the “top”, "
but the example given in the PostGIS documentation
http://postgis.refractions.net/documentation/manual-1.3/ch04.html#RefObject
gives an interior ring with counter-clockwise orientation. Am I missing
something?
Thanks, Tara
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