Changes

CityGML 2.0 strongly recommends the specification of a reference coordinate system.  For a meaningful use of data a valid reference coordinate system is imperative, therefore a valid reference coordinate system must be defined for each instance file:

CityGML 2.0 strongly recommends the specification of a reference coordinate system.  For a meaningful use of data a valid reference coordinate system is imperative, therefore a valid reference coordinate system must be defined for each instance file:

* A reference coordinate system must be defined as '''three dimensional''' (usually position and height reference system --> [[Definitionen#CCRS|siehe Compound Coordinate Referencesystem]]).

* A reference coordinate system must be defined as '''three dimensional''' (usually position and height reference system --> [[Definitionen#CCRS|see Compound Coordinate Reference System]]).

* A reference coordinate system should '''not''' be changed within an instance file.

* A reference coordinate system should '''not''' be changed within an instance file.

* A reference coordinate system should be defined once within ''<gml:Envelope>''.

* A reference coordinate system should be defined once within <tt><gml:Envelope></tt>.

'''CityGML Example:'''

'''CityGML Example:'''

''<gml:boundedBy>

 

<gml:boundedBy>

&nbsp;&nbsp;&nbsp;&nbsp;''<gml:Envelope srsDimension="3" srsName="'''urn:adv:crs:ETRS89_UTM32*DE_DHHN92_NH'''">''

  <gml:Envelope srsDimension="3" srsName="'''urn:adv:crs:ETRS89_UTM32*DE_DHHN92_NH'''">

 

  '''--> [[Definitionen#Kombi-Lage-Hoehe|see Kombinationen von Lage- und Höhenbezugsystemen in ALKIS]]'''

&nbsp;&nbsp;&nbsp;&nbsp;'''--> [[Definitionen#Kombi-Lage-Hoehe|see Kombinationen von Lage- und Höhenbezugsystemen in ALKIS]]'''

      <gml:lowerCorner srsDimension="3">458868.0 5438343.0 112.0 </gml:lowerCorner>

 

      <gml:upperCorner srsDimension="3">458892.0 5438362.0 117.0 </gml:upperCorner>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;''<gml:lowerCorner srsDimension="3">458868.0 5438343.0 112.0 </gml:lowerCorner>''

  </gml:Envelope>

 

</gml:boundedBy>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;''<gml:upperCorner srsDimension="3">458892.0 5438362.0 117.0 </gml:upperCorner>''

 

&nbsp;&nbsp;&nbsp;&nbsp;''</gml:Envelope>''

 

''</gml:boundedBy>''

 

'''ALKIS Example:'''

'''ALKIS Example:'''

''<gml:boundedBy>''

 

<gml:boundedBy>

&nbsp;&nbsp;&nbsp;&nbsp;''<gml:Envelope srsName="'''urn:adv:crs:ETRS89_UTM32'''">''

    <gml:Envelope srsName="'''urn:adv:crs:ETRS89_UTM32'''">

 

      <gml:pos>367456.554 5718128.391</gml:pos>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;''<gml:pos>367456.554 5718128.391</gml:pos>''

      <gml:pos>367505.094 5718091.143</gml:pos>

 

    </gml:Envelope>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;''<gml:pos>367505.094 5718091.143</gml:pos>''

</gml:boundedBy>

 

&nbsp;&nbsp;&nbsp;&nbsp;''</gml:Envelope>''

 

''</gml:boundedBy>''

 

see also [[Handbuch für die Modellierung von 3D Objekten - Teil 1: Grundlagen (Regeln für valide GML Geometrie-Elemente in CityGML)#Spatial-Reference-System|Handbuch - Teil 1]]

see also [[Handbuch für die Modellierung von 3D Objekten - Teil 1: Grundlagen (Regeln für valide GML Geometrie-Elemente in CityGML)#Spatial-Reference-System|Handbuch - Teil 1]]