4.5.3 Element Voiding

Elements may have voids defined, which may be partial recess or extending full depth. Voids for openings may optionally be filled by another element such as a door, window, earthen or aggregate fill, or may represent a voiding feature without fillings.

The 'Body' representation of an element does not account for voids, for which CSG operations are required to produce the resulting shape.

The 'Mesh' representation of an element does account for voids, such that no additional operations are required.

Figure 155 illustrates an instance diagram.

Element VoidingIfcElementIfcRelVoidsElement

Figure 155 — Element Voiding

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="b9005e79-b5c5-4c0b-9d86-046c21ad420d" name="Element Voiding" applicableSchema="IFC4" applicableEntity="IfcElement">
  <Rules>
    <AttributeRule RuleID="HasOpenings" AttributeName="HasOpenings">
      <EntityRules>
        <EntityRule EntityName="IfcRelVoidsElement" />
      </EntityRules>
    </AttributeRule>
  </Rules>
  <SubTemplates>
    <ConceptTemplate uuid="e2d1e67a-b584-476c-878e-132af9f8e2b8" name="Element Openings" applicableSchema="IFC4" applicableEntity="IfcElement">
      <Rules>
        <AttributeRule RuleID="HasOpenings" AttributeName="HasOpenings">
          <EntityRules>
            <EntityRule EntityName="IfcRelVoidsElement">
              <AttributeRules>
                <AttributeRule RuleID="RelatedOpeningElement" AttributeName="RelatedOpeningElement">
                  <EntityRules>
                    <EntityRule EntityName="IfcOpeningElement">
                      <AttributeRules>
                        <AttributeRule RuleID="OpeningElementType" AttributeName="PredefinedType">
                          <EntityRules>
                            <EntityRule EntityName="IfcOpeningElementTypeEnum" />
                          </EntityRules>
                        </AttributeRule>
                        <AttributeRule RuleID="FillsVoids" AttributeName="FillsVoids">
                          <EntityRules>
                            <EntityRule EntityName="IfcRelFillsElement">
                              <AttributeRules>
                                <AttributeRule RuleID="RelatedBuiltElement" AttributeName="RelatedBuildingElement">
                                  <EntityRules>
                                    <EntityRule EntityName="IfcDoor" />
                                    <EntityRule EntityName="IfcWindow" />
                                  </EntityRules>
                                </AttributeRule>
                              </AttributeRules>
                            </EntityRule>
                          </EntityRules>
                        </AttributeRule>
                      </AttributeRules>
                    </EntityRule>
                  </EntityRules>
                </AttributeRule>
              </AttributeRules>
            </EntityRule>
          </EntityRules>
        </AttributeRule>
      </Rules>
    </ConceptTemplate>
    <ConceptTemplate uuid="5b37561e-5789-4f06-89b8-59a00a04376e" name="Element Voiding Features" applicableSchema="IFC4" applicableEntity="IfcElement">
      <Rules>
        <AttributeRule RuleID="HasOpenings" AttributeName="HasOpenings">
          <EntityRules>
            <EntityRule EntityName="IfcRelVoidsElement">
              <AttributeRules>
                <AttributeRule RuleID="RelatedVoidingFeature" AttributeName="RelatedOpeningElement">
                  <EntityRules>
                    <EntityRule EntityName="IfcVoidingFeature">
                      <AttributeRules>
                        <AttributeRule RuleID="VoidingFeatureType" AttributeName="PredefinedType">
                          <EntityRules>
                            <EntityRule EntityName="IfcVoidingFeatureTypeEnum" />
                          </EntityRules>
                        </AttributeRule>
                      </AttributeRules>
                    </EntityRule>
                  </EntityRules>
                </AttributeRule>
              </AttributeRules>
            </EntityRule>
          </EntityRules>
        </AttributeRule>
      </Rules>
    </ConceptTemplate>
    <ConceptTemplate uuid="dbb05c46-12f4-4bdc-89f5-d7c9d5c075ce" name="Excavation Cuttings" applicableSchema="IFC4" applicableEntity="IfcElement">
      <Rules>
        <AttributeRule RuleID="HasOpenings" AttributeName="HasOpenings">
          <EntityRules>
            <EntityRule EntityName="IfcRelVoidsElement">
              <AttributeRules>
                <AttributeRule RuleID="RelatedEarthworksCut" AttributeName="RelatedOpeningElement">
                  <EntityRules>
                    <EntityRule EntityName="IfcExcavation">
                      <AttributeRules>
                        <AttributeRule RuleID="FillsVoids" AttributeName="FillsVoids">
                          <EntityRules>
                            <EntityRule EntityName="IfcRelFillsElement">
                              <AttributeRules>
                                <AttributeRule RuleID="RelatedBuiltElement" AttributeName="RelatedBuildingElement">
                                  <EntityRules>
                                    <EntityRule EntityName="IfcCourse" />
                                    <EntityRule EntityName="IfcDeepFoundation" />
                                    <EntityRule EntityName="IfcEarthworksFill" />
                                    <EntityRule EntityName="IfcFooting" />
                                    <EntityRule EntityName="IfcPavement" />
                                    <EntityRule EntityName="IfcSlab" />
                                  </EntityRules>
                                </AttributeRule>
                              </AttributeRules>
                            </EntityRule>
                          </EntityRules>
                        </AttributeRule>
                      </AttributeRules>
                    </EntityRule>
                  </EntityRules>
                </AttributeRule>
              </AttributeRules>
            </EntityRule>
          </EntityRules>
        </AttributeRule>
      </Rules>
    </ConceptTemplate>
  </SubTemplates>
</ConceptTemplate>

Link to this page  Link to this page