[ready] Visible material

In AIXM 5 the predominantly visible material composing the obstacle may be coded for each individual VerticalStructurePart using the visibleMaterial attribute.

Example 1: Material

Example 1: Material

		<aixm:VerticalStructure gml:id="uuid.66e649c8-aaba-4fac-9432-7ee33f90e2d5">
			<gml:identifier codeSpace="urn:uuid:">66e649c8-aaba-4fac-9432-7ee33f90e2d5</gml:identifier>
			...
					<aixm:type>OTHER:WINDSOCK</aixm:type>
					...
					<aixm:part>
						<aixm:VerticalStructurePart gml:id="V-af4ee6d6">
							..
							<!-- visibleMaterial not required by PANS-AIM but contained in Appendix 1 "Aeronautical Data Catalogue" ("Material")-->
							<aixm:visibleMaterial xsi:nil="true" nilReason="unknown"/>
							...