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IfcPointLightSource

Definition from IAI: Pointlight is a light source that emits light from a specified location evenly in all directions. The light may attenuate with distance, and it may have a cut-off radius.

HISTORY New Entity in IFC 2x.
ISSUE See issue and change log for changes made in IFC 2x.

EXPRESS specification:

ENTITY IfcPointLightSource
SUBTYPE OF ( IfcPresentationLightSource);
Location  :  IfcCartesianPoint;
Attenuation  :  LIST [1:3] OF REAL;
WHERE
WR21  :  SIZEOF(QUERY(temp <* Attenuation | temp < 0.)) = 0;
END_ENTITY;

Attribute definitions:

Location  :  Location of the ligth source in the WCS defined by the related geometric represenation context.
Attenuation  :  Attenuation coefficients: [constant, linear, quadratic].
For usage, see VRML97 - ISO/IEC 14772-1:1997.

Formal Propositions:

WR21  :  Attenuation coefficients shall be non-negative.

References (2):

Name Type Referred through Express-G
IfcPresentationLightSource Entity
Subtype
Diagram 2
IfcSpotLightSource Entity
Supertype
Diagram 2

Inheritance graph

ENTITY IfcPointLightSource;
ENTITY IfcPresentationLightSource;
Color  :  IfcColorRGB;
AmbientIntensity  :  IfcNormalisedRatioMeasure;
Intensity  :  IfcNormalisedRatioMeasure;
InContext  :  IfcGeometricRepresentationContext;
Name  :  IfcLabel;
Description  :  OPTIONAL IfcText;
ENTITY IfcPointLightSource;
Location  :  IfcCartesianPoint;
Attenuation  :  LIST [1:3] OF REAL;
END_ENTITY;