注：根据ISO 10303-46的定义：
光源环境图元是光源的子类型。它将照亮与曲面的方向和位置无关的曲面。
注：相应的ISO 10303实体：光源环境。有关正式标准的最终定义，请参考ISO/IS 10303-46:1994，第31页。
注：除ISO 10303-46中定义的属性外，ISO/IEC 14772-1:1997（VRML）Ambientity的附加属性继承自父类型。
IFC2x中增加的新实体，在IFC2x2中重命名和增强。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| IfcRepresentationItem | |||||
| LayerAssignment | IfcPresentationLayerAssignment @AssignedItems |
S[0:1] | 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. | X | |
| StyledByItem | IfcStyledItem @Item |
S[0:1] | Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. | X | |
| IfcGeometricRepresentationItem | |||||
| IfcLightSource | |||||
| 1 | Name | IfcLabel | [0:1] | The name given to the light source in presentation. | X |
| 2 | LightColour | IfcColourRgb | [1:1] | 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. | X |
| 3 | AmbientIntensity | IfcNormalisedRatioMeasure | [0:1] | 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). | X |
| 4 | Intensity | IfcNormalisedRatioMeasure | [0:1] | 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). | X |
| IfcLightSourceAmbient | |||||
ENTITY IfcLightSourceAmbient
SUBTYPE OF (IfcLightSource);
END_ENTITY;
原文：https://www.cnblogs.com/herd/p/13356988.html