NOTE Definition according to ISO 10303-46:
The light source entity is determined by the reflectance specified in the surface style rendering. Lighting is applied on a surface by surface basis: no interactions between surfaces such as shadows or reflections are defined.
NOTE Entity adapted from light_source defined in ISO 10303-46.
NOTE In addition to the attributes as defined in ISO10303-46 the following additional properties from ISO/IEC 14772-1:1997 (VRML) are added: ambientIntensity and Intensity. The attribute Name has been added as well (as it is not inherited via representation_item).
HISTORY New entity in IFC2x, renamed and enhanced in IFC2x2.
|LayerAssignment||SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems||Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.|
> IFC2x3 CHANGE The inverse attribute LayerAssignments has been added.
> IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
|StyledByItem||SET [0:1] OF IfcStyledItem FOR Item||Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.|
> IFC2x3 CHANGE The inverse attribute StyledByItem has been added.
|1||Name||OPTIONAL IfcLabel||The name given to the light source in presentation.|
|2||LightColour||IfcColourRgb||Definition from ISO/CD 10303-46:1992: Based on the current lighting model, the colour of the light to be used for shading.|
Definition from VRML97 - ISO/IEC 14772-1:1997: The color field specifies the spectral color properties of both the direct and ambient light emission as an RGB value.
|3||AmbientIntensity||OPTIONAL IfcNormalisedRatioMeasure||Definition from VRML97 - ISO/IEC 14772-1:1997: The ambientIntensity specifies the intensity of the ambient emission from the light. Light intensity may range from 0.0 (no light emission) to 1.0 (full intensity).|
|4||Intensity||OPTIONAL IfcNormalisedRatioMeasure||Definition from VRML97 - ISO/IEC 14772-1:1997: The intensity field specifies the brightness of the direct emission from the ligth. Light intensity may range from 0.0 (no light emission) to 1.0 (full intensity).|
ENTITY IfcLightSource ABSTRACT SUPERTYPE OF (ONEOF (IfcLightSourceAmbient ,IfcLightSourceDirectional ,IfcLightSourceGoniometric ,IfcLightSourcePositional)) SUBTYPE OF (IfcGeometricRepresentationItem); Name : OPTIONAL IfcLabel; LightColour : IfcColourRgb; AmbientIntensity : OPTIONAL IfcNormalisedRatioMeasure; Intensity : OPTIONAL IfcNormalisedRatioMeasure; END_ENTITY;