4.8.1.7 CoG Geometry

Elements may have a 'CoG' representation describing the Center of Gravity as a point. Such representation may be used for allowing validation checks to verify, that the CoG after import of the 'Body' shape representation matches this explicit value created during export, taking acceptable numeric tolerances into account.

The representation identifier and type and the only allowed single representation item of the 'CoG' representation are:

Figure 235 illustrates an instance diagram.

CoG GeometryIfcProductIfcProductDefinitionShapeIfcShapeRepresentationIfcGeometricRepresentationContextIfcLabelIfcLabelIfcCartesianPoint

Figure 235 — CoG Geometry

mvdXML Specification
<?xml version="1.0" encoding="utf-8"?>
<ConceptTemplate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="a13f0eca-6c45-4a95-bfa6-03cc7da6a6cf" name="CoG Geometry" applicableSchema="IFC4" applicableEntity="IfcProduct">
  <Rules>
    <AttributeRule AttributeName="Representation">
      <EntityRules>
        <EntityRule EntityName="IfcProductDefinitionShape">
          <AttributeRules>
            <AttributeRule AttributeName="Name" />
            <AttributeRule AttributeName="Description" />
            <AttributeRule AttributeName="Representations">
              <EntityRules>
                <EntityRule EntityName="IfcShapeRepresentation">
                  <AttributeRules>
                    <AttributeRule AttributeName="ContextOfItems">
                      <EntityRules>
                        <EntityRule EntityName="IfcGeometricRepresentationContext" />
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule RuleID="Identifier" AttributeName="RepresentationIdentifier">
                      <EntityRules>
                        <EntityRule EntityName="IfcLabel">
                          <Constraints>
                            <Constraint Expression="Identifier[Value] = 'CoG'" />
                          </Constraints>
                        </EntityRule>
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule RuleID="Type" AttributeName="RepresentationType">
                      <EntityRules>
                        <EntityRule EntityName="IfcLabel" />
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule AttributeName="Items">
                      <EntityRules>
                        <EntityRule EntityName="IfcCartesianPoint" />
                      </EntityRules>
                    </AttributeRule>
                  </AttributeRules>
                </EntityRule>
              </EntityRules>
            </AttributeRule>
          </AttributeRules>
        </EntityRule>
      </EntityRules>
    </AttributeRule>
  </Rules>
</ConceptTemplate>

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