IfcLightDistributionCurveEnum

Semantic definitions at the type

Type definition

There are three kinds of light distribution curves, see Figure 374.

NOTE The classification as type A, B, C is according to Standard CEN TC 169, prEN 13032-1, CIE 121:


B-Type System	C-Type System

Figure 374 — Light distribution curves

HISTORY New enumeration in IFC2x2.

Enumeration definition

Constant	Description
TYPE_A	Type A is basically not used. For completeness the Type A Photometry equals the Type B rotated 90° around the Z-Axis counter clockwise.
TYPE_B	Type B is sometimes used for floodlights. The B-Plane System has a horizontal axis. B-Angles are valid from -180° to +180° with B 0° at the bottom and B180°/B-180° at the top, β-Angles are valid from -90° to +90°.
TYPE_C	Type C is the recommended standard system. The C-Plane system equals a globe with a vertical axis. C-Angles are valid from 0° to 360°, γ-Angles are valid from 0° (south pole) to 180° (north pole).
NOTDEFINED

Formal representations

XSD Specification

 <xs:simpleType name="IfcLightDistributionCurveEnum">

  <xs:restriction base="xs:string">

   <xs:enumeration value="type_a"/>

   <xs:enumeration value="type_b"/>

   <xs:enumeration value="type_c"/>

   <xs:enumeration value="notdefined"/>

  </xs:restriction>

 </xs:simpleType>

EXPRESS Specification


TYPE IfcLightDistributionCurveEnum = ENUMERATION OF (

 TYPE_A, 
 TYPE_B, 
 TYPE_C, 
 NOTDEFINED);
END_TYPE;


 EXPRESS-G diagram

	Light Distribution Curve Enum
	Enumération des courbes de distribution lumineuse