#### 8.12.3.1 IfcLightSource

| Source de lumière
| Lichtquelle

> 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.

XSD Specification:

<xs:element name="IfcLightSource" type="ifc:IfcLightSource" abstract="true" substitutionGroup="ifc:IfcGeometricRepresentationItem" nillable="true"/>
<xs:complexType name="IfcLightSource" abstract="true">
<xs:complexContent>
<xs:extension base="ifc:IfcGeometricRepresentationItem">
<xs:sequence>
<xs:element name="LightColour" type="ifc:IfcColourRgb" nillable="true"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcLightSource

| SUBTYPE OF (IfcGeometricRepresentationItem);

Name | : | OPTIONAL IfcStrippedOptional;
LightColour | : | IfcColourRgb;
AmbientIntensity | : | OPTIONAL IfcStrippedOptional;
Intensity | : | OPTIONAL IfcStrippedOptional;

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

LayerAssignment | : | SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem | : | SET [0:1] OF IfcStyledItem FOR Item;

| ENTITY IfcGeometricRepresentationItem

| ENTITY IfcLightSource

Name | : | OPTIONAL IfcStrippedOptional;
LightColour | : | IfcColourRgb;
AmbientIntensity | : | OPTIONAL IfcStrippedOptional;
Intensity | : | OPTIONAL IfcStrippedOptional;

END_ENTITY;

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