geometryBasic2d.xsd Subset of geometryBasic2d.xsd for WCS 1.2 profile. Primary editor: Primary editor: Arliss Whiteside. Copyright (c) 2007,2010 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . The "_Surface" element is the abstract head of the substituition group for all (continuous) surface elements. An abstraction of a surface to support the different levels of complexity. A surface is always a continuous region of a plane. A Polygon is a special surface that is defined by a single surface patch. The boundary of this patch is coplanar and the polygon uses planar interpolation in its interior. It is backwards compatible with the Polygon of GML 2, GM_Polygon of ISO 19107 is implemented by PolygonPatch. The "_Ring" element is the abstract head of the substituition group for all closed boundaries of a surface patch. An abstraction of a ring to support surface boundaries of different complexity. A boundary of a surface consists of a number of rings. In the normal 2D case, one of these rings is distinguished as being the exterior boundary. In a general manifold this is not always possible, in which case all boundaries shall be listed as interior boundaries, and the exterior will be empty. Encapsulates a ring to represent the surface boundary property of a surface. A LinearRing is defined by four or more coordinate tuples, with linear interpolation between them; the first and last coordinates must be coincident. The "posList" element provides a compact way to specifiy the coordinates of the control points, assuming all control points are in the same coordinate reference systems. The number of direct positions in the list must be at least four.