<complexType name="TinType">
	<annotation>
		<documentation>A tin is a triangulated surface that uses
  the Delauny algorithm or a similar algorithm complemented with
  consideration of breaklines, stoplines, and maximum length of 
  triangle sides. These networks satisfy the Delauny's criterion
  away from the modifications: Fore each triangle in the 
  network, the circle passing through its vertices does not
  contain, in its interior, the vertex of any other triangle.</documentation>
	</annotation>
	<complexContent>
		<extension base="gml:TriangulatedSurfaceType">
			<sequence>
				<element name="stopLines" type="gml:LineStringSegmentArrayPropertyType" minOccurs="0" maxOccurs="unbounded">
					<annotation>
						<documentation>Stoplines are lines where the local
      continuity or regularity of the surface is questionable.
      In the area of these pathologies, triangles intersecting
      a stopline shall be removed from the tin surface, leaving
      holes in the surface. If coincidence occurs on surface
      boundary triangles, the result shall be a change of the 
      surface boundary. Stoplines contains all these
      pathological segments as a set of line strings.</documentation>
					</annotation>
				</element>
				<element name="breakLines" type="gml:LineStringSegmentArrayPropertyType" minOccurs="0" maxOccurs="unbounded">
					<annotation>
						<documentation>Breaklines are lines of a critical
      nature to the shape of the surface, representing local
      ridges, or depressions (such as drainage lines) in the
      surface. As such their constituent segments must be
      included in the tin eve if doing so
      violates the Delauny criterion. Break lines contains these
      critical segments as a set of line strings.</documentation>
					</annotation>
				</element>
				<element name="maxLength" type="gml:LengthType">
					<annotation>
						<documentation>Areas of the surface where data is not 
      sufficiently dense to assure reasonable calculation shall be    
      removed by adding a retention criterion for triangles based 
      on the length of their sides. For many triangle sides  
      exceeding maximum length, the adjacent triangles to that 
      triangle side shall be removed from the surface.</documentation>
					</annotation>
				</element>
				<element name="controlPoint">
					<annotation>
						<documentation>The corners of the triangles in the TIN 
 are often referred to as pots. ControlPoint shall contain a 
 set of the GM_Position used as posts for this TIN. Since each  
 TIN contains triangles, there must be at least 3 posts. The 
      order in which these points are given does not affect the 
      surface that is represented. Application schemas may add 
      information based on ordering of control points to facilitate 
      the reconstruction of the TIN from the control points.</documentation>
					</annotation>
					<complexType>
						<choice>
							<element ref="gml:posList"/>
							<group ref="gml:geometricPositionGroup" minOccurs="3" maxOccurs="unbounded"/>
						</choice>
					</complexType>
				</element>
			</sequence>
		</extension>
	</complexContent>
</complexType>