Model Geographic Element

Overview

Provides the information concerning geographic elements represented within a map or geographic space (external to a building).
The term geographical element is is used to include items such as:

archaeological items;
network items such as roads, rivers etc.
street furniture such as traffic lights, street lights, bus shelters and the like;
trees and plants;
non building constructions including markers, cairns, statuary and the like;
...etc.

Note that in GIS applications, the term 'feature' is commonly used to identify geographic elements. However, the term 'feature' is used in IFC in the sense that it is normally used in geometric modelling for manufacturing systems and is thus not available for the normal GIS purpose. Hence the term 'geographic element' is used as a synonym.
This functional part describes both the establishment of the geographic element type and the assignment of that type to an occurrence of a geographic element. It should be noted that types can be defined and exchanged without the need to exchange occurrences. For this purpose, references to occurrences below can be omitted.

Results

Model of geographic element occurrence(s) that are defined by type. Model including shape representation and bq._other relevant information

Description	Entity/Pset/Functional Part	MAN	REC	OPT
Define the geographical element type that is to be used This is a text label determined by the user and assigned to the attribute ElementType. Values that may be assigned to the label should be agreed between users. In many cases, for geographic elements, there are likely to be national or regional feature codes with associated names; it is recommended that names in such codes are agreed as applicable values.	IfcGeographicalElementType.ElementType::IfcLabel
Set the value of the applicable occurrence of the geographic element type to IfcGeographicElement. This sets the occurrence entity to which the type can relate.	IfcGeographicalElementType.ApplicableOccurrence::IfcLabel
Set the value of the type identifier if required. This may be a specific identifier such as an article number	IfcGeographicalElementType.Tag::IfcLabel
Determine the required form of shape representation according to the geographic element type. More detailed guidance of the shape representation to be used is given in relevant exchange requirements. Shape representation is not required for exchanges that do not involve geometric requirements. However, for most cases, it is anticipated that shape will be included.
For geographic element types that have consistent shapes, these may be defined using a representation map. An example of such a type might be a tree. Note that entity may use more than one representation map.	IfcGeographicalElementType.RepresentationMaps::fp_map_representation
For geographic element types that do not have consistent shapes, the shape representation should be explicitly defined for the occurrence. _An example of such a type might be a road element.	IfcGeographicalElement.Representation::fp_represent_product
Place an occurrence of a geographic element	IfcGeographicalElement.ObjectPlacement::fp_place_object
Set the value of the object type according to the geographic element type used. This should be equivalent to the value of the ElementType used for the geographic element type and set according to the usage context.	IfcGeographicalElement.ObjectType::IfcLabel
Set the value of the occurrence identifier if required. This may be an occurrence identifier such as a serial number	IfcGeographicalElement.Tag::IfcLabel
Define the geographic element occurrence according to the type	fp_define_by_type
Specify the property sets that should be applied to the geographic element type for the particular occurrence. Each type of geographic element will have one or more property sets that define the properties normally associated with that type. The particular property sets that may be are further elaborated in exchange requirements.	IfcGeographicalElementType.HasPropertySets::IfcPropertySet
Specify the property values required. The particular property values that may need to be set are further elaborated in exchange requirements.

IFC Entities Required

IfcElement
IfcElementType
IfcGeographicElement
IfcGeographicElementType
IfcObject
IfcObjectDefinition
IfcProduct
IfcPropertyDefinition
IfcPropertySetDefinition
IfcPropertySet
IfcRoot
IfcTypeObject
IfcTypeProduct

IFC Datatypes Required

IfcGloballyUniqueId
IfcIdentifier
IfcLabel
IfcText

IFC Functions Required

-

IFC Property Sets Required

xx

IDM Functional Parts Required

fp_apply_owner_history
fp_define_by_type
fp_map_representation
fp_place_object
fp_property
fp_represent_product

EXPRESS Schema

SCHEMA FP_MODEL_GEOGRAPHIC_ELEMENT;

  TYPE IfcGloballyUniqueId = STRING (22) FIXED;
  END_TYPE;

  TYPE IfcIdentifier = STRING;
  END_TYPE;

  TYPE IfcLabel = STRING;
  END_TYPE;

  TYPE IfcText = STRING;
  END_TYPE;

  ENTITY IfcProduct
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcObject);
      Representation  : OPTIONAL fp_represent_product;
      ObjectPlacement : OPTIONAL fp_place_object;
    WHERE
      WR1 : (EXISTS(Representation) AND EXISTS(ObjectPlacement))
            OR (EXISTS(Representation) AND
            (NOT('IFC2X2_FINAL.IFCPRODUCTDEFINITIONSHAPE' IN TYPEOF(Representation))))
            OR (NOT(EXISTS(Representation)));
  END_ENTITY;

  ENTITY IfcObject
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcObjectDefinition);
      ObjectType : OPTIONAL IfcLabel;
    WHERE
      WR1 : SIZEOF(QUERY(temp <* IsDefinedBy | 'IFC2X2_FINAL.IFCRELDEFINESBYTYPE' IN TYPEOF(temp))) <= 1;
  END_ENTITY;

  ENTITY IfcRoot
    ABSTRACT SUPERTYPE OF (ONEOF(IfcObjectDefinition, IfcPropertyDefinition));
      GlobalId     : IfcGloballyUniqueId;
      Name         : OPTIONAL IfcLabel;
      Description  : OPTIONAL IfcText;
      OwnerHistory : fp_apply_owner_history;
    UNIQUE
      UR1 : GlobalId;
  END_ENTITY;

  ENTITY IfcPropertyDefinition
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcRoot);
  END_ENTITY;

  ENTITY IfcPropertySetDefinition
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcPropertyDefinition);
    INVERSE
      DefinesType : SET [0:1] OF IfcTypeObject FOR HasPropertySets;
  END_ENTITY;

  ENTITY IfcPropertySet
    SUBTYPE OF(IfcPropertySetDefinition);
      HasProperties : SET [1:?] OF fp_property;
    WHERE
      WR31 : EXISTS(SELF\IfcRoot.Name);
      WR32 : IfcUniquePropertyName(HasProperties);
  END_ENTITY;

  ENTITY IfcElement
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcProduct);
      Tag : OPTIONAL IfcIdentifier;
  END_ENTITY;

  ENTITY IfcTypeObject
    SUBTYPE OF(IfcObjectDefinition);
      ApplicableOccurrence : OPTIONAL IfcLabel;
      HasPropertySets      : OPTIONAL LIST [1:?] OF IfcPropertySetDefinition;
    WHERE
      WR1 : EXISTS(SELF\IfcRoot.Name);
  END_ENTITY;

  ENTITY IfcTypeProduct
    SUBTYPE OF(IfcTypeObject);
      Tag                : OPTIONAL IfcLabel;
      RepresentationMaps : OPTIONAL SET [1:?] OF fp_map_representation;
    WHERE
      WR41 : NOT(EXISTS(SELF\IfcTypeObject.ObjectTypeOf[1])) OR
             (SIZEOF(QUERY(temp <* SELF\IfcTypeObject.ObjectTypeOf[1].RelatedObjects |
             NOT('IFC2X2_FINAL.IFCPRODUCT' IN TYPEOF(temp)))
             ) = 0);
  END_ENTITY;

  ENTITY IfcElementType
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcTypeProduct);
      ElementType : OPTIONAL IfcLabel;
  END_ENTITY;

  ENTITY IfcObjectDefinition
    SUPERTYPE OF (ONEOF(IfcObject, IfcTypeObject))
    SUBTYPE OF(IfcRoot);
  END_ENTITY;

  ENTITY IfcGeographicElement
    SUBTYPE OF(IfcElement);
  END_ENTITY;

  ENTITY IfcGeographicElementType
    SUBTYPE OF(IfcElementType);
  END_ENTITY;

  ENTITY fp_apply_owner_history;
  END_ENTITY;

  ENTITY fp_place_object;
  END_ENTITY;

  ENTITY fp_represent_product;
  END_ENTITY;

  ENTITY fp_map_representation;
  END_ENTITY;

  ENTITY fp_property;
  END_ENTITY;

  ENTITY fp_define_by_type;
  END_ENTITY;

END_SCHEMA;

Page Operations

Browse Space