IfcLightSource

Definition from ISO/CD 10303-46:1992: 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: Corresponding STEP entity: light_source. Please refer to ISO/IS 10303-46:1994, p. 31 for the final definition of the formal standard.

> 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: This is a new Entity in IFC 2x, renamed and enhanced in IFC2x2.

EXPRESS specification:

ENTITY IfcLightSource
ABSTRACT SUPERTYPE OF | (ONEOF(IfcLightSourceAmbient, IfcLightSourceDirectional, IfcLightSourcePositional, IfcLightSourceGoniometric))
SUBTYPE OF ( | IfcGeometricRepresentationItem);
Name | : | OPTIONAL IfcLabel;
LightColour | : | IfcColourRgb;
AmbientIntensity | : | OPTIONAL IfcNormalisedRatioMeasure;
Intensity | : | OPTIONAL IfcNormalisedRatioMeasure;
END_ENTITY;

Attribute definitions:

Name | : | The name given to the light source in presentation.
LightColour | : | 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.
AmbientIntensity | : | 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).
Intensity | : | 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).

Inheritance graph

ENTITY IfcLightSource;
ENTITY IfcRepresentationItem;
INVERSE
LayerAssignments | : | SET OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcGeometricRepresentationItem;
ENTITY IfcLightSource;
Name | : | OPTIONAL IfcLabel;
LightColour | : | IfcColourRgb;
AmbientIntensity | : | OPTIONAL IfcNormalisedRatioMeasure;
Intensity | : | OPTIONAL IfcNormalisedRatioMeasure;
END_ENTITY;