Explanation of the syntax in the association configuration file for IFC export

The standard configuration file is shipped with the installation and is located here:

"<installation directory>\Novapoint\Configuration\Schemas\IFC\IfcRelationshipConfig.xml"

How the configuration file works

This configuration file defines the spatial breakdown structure and/or the functional systems included in the exported IFC-file. These breakdown structures are not supported by Quadri and must therefore be created when exporting the IFC-file. A spatial breakdown structure is mandatory in an IFC-file.

In this configuration file you can define new spatial entities and system entities. In addition, you can specify which “physical entities” should be associated to these spatial/system entities. These association “levels” can be nested to build up a tree-structure. 

This configuration file is processed after the object conversion, so objects created by the conversion process (“physical entities”) can be specified/referenced in this configuration file. 

The entities ifcProject, ifcSite and ifcGeomodel are defined on the Version tab in the Settings dialog. These entities can be specified/referenced in this configuration file too.

Examples of new spatial/system entities you can define in this configuration file are: ifcRoad, ifcRoadPart, ifcGroup, ifElementAssembly, ifcDistributionSystem etc.. You can create new entities in the configuration file for all entities defined in the IFC-schema, but in most cases you will only need to create spatial entities for the spatial breakdown structure and “grouping” entities for the functional systems.

The syntax of the configuration file

The upper part of the configuration file is shown below:

• RelationshipConfig: This is the whole association section in the configuration file.

• ifcObjectType: This section contains a level in the spatial breakdown structure or functional system.
  These sections can be nested as shown above, to define the total tree-structure.

• Entity: Here you specify the entity name as defined in the IFC-schema.

• PredefinedType: Here you specify the value of the PredefinedType attribute defined in the IFC-schema.
  This is an enumeration value defined in the IFC-schema or the value USERDEFINED used together with the ObjectType attribute value.

• ObjectType: Here you specify the value of the ObjectType attribute defined in the IFC-schema.

• UsageType: Here you specify the value of the UsageType attribute defined in the IFC-schema. This attribute is in use for some entity types, like ifcRoadPart e.g.

• Tag: Here you specify the value of the Tag attribute defined in the IFC-schema

• Relationship: Here you specify the association type between this entity and the entity above in the spatial breakdown structure or functional system. Valid Relationship values are:

• CISS: Contained in spatial structure (ifcRelContainedInSpatialStructure)

• RISS: Referenced in spatial structure (ifcRelReferencedInSpatialStructure)

• AGGR: Aggregated (ifcRelAggregates)

• VOID: Voids (ifcRelVoidsElement) – used for cutting openings in other objects

• Description: Here you can enter a description for new entities defined in the configuration file.

The combined values of the Entity, PredefinedType, ObjectType, UsageType and Tag attributes of the objects created by the applied conversion rule, are used for selecting the objects to be associated to the entity defined above in the tree-structure in the configuration file. Blank values are not considered.

For the new entities created by the configuration file, you can specify the values of the attributes Entity, PredefinedType, ObjectType, UsageType, Tag and Description in the configuration file. For now, the names of the entities created by the conversion rule are (partly) hardcoded. In future versions this will be possible to specify in the conversion file.

How to separate between different tasks

You usually want to have separate the spatial breakdown structure branches and/or the functional systems for the different tasks in Quadri, like road tasks or water and sewer tasks e.g..

When the export contains more than one task of the same type, the configuration file processing will use the Task Type and Task GUID attributes to sort which objects belong to which task. These attribute values must be defined in the conversion rule, as shown in the image below.

Note:

If there are some exported «physical entities» that are not contained in the spatial breakdown structure after this config-file has been processes, then they are collected in an ifcElementAssembly named “Default”. This assembly is associated to the ifcSite in the spatial breakdown structure. The values for PredefinedType, ObjectType and Tag are all blank for this assembly.