4.1.2.2.8 Parabolic Transition Segment

The parabolic transition segment is modelled with IfcPolynomialCurve with certain restrictions. The size of the attribute CoefficientsY is restricted to 3. The quadratic term is on position 3. In general, the CoefficientsX size would be restricted to 2 and values specified as [0, 1]. This produces the following result:

y = CoefficientsX[3]*x², where other values in CoefficientsY are 0.

Figure 14 illustrates an instance diagram.

Parabolic Transition SegmentIfcCurveSegmentIfcPolynomialCurveIfcRealIfcReal

Figure 14 — Parabolic Transition Segment

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="cd1ee45e-f96e-464a-a324-478d74bb894b" name="Parabolic Transition Segment" applicableSchema="IFC4" applicableEntity="IfcCurveSegment">
  <Rules>
    <AttributeRule AttributeName="ParentCurve">
      <EntityRules>
        <EntityRule EntityName="IfcPolynomialCurve">
          <AttributeRules>
            <AttributeRule AttributeName="CoefficientsX">
              <EntityRules>
                <EntityRule EntityName="IfcReal" />
              </EntityRules>
            </AttributeRule>
            <AttributeRule AttributeName="CoefficientsY">
              <EntityRules>
                <EntityRule EntityName="IfcReal" />
              </EntityRules>
            </AttributeRule>
          </AttributeRules>
        </EntityRule>
      </EntityRules>
    </AttributeRule>
  </Rules>
</ConceptTemplate>

Link to this page  Link to this page