IfcLightSourceGoniometric

IfcLightSourceGoniometric定义一个光源，该光源的确切照明数据可用。它指定光源发射器的类型，定义光分布曲线的位置和方向，以及有关灯和光度控制信息的数据。

下图显示了具有两个光源（ifclightsourcegonometric类型）的光源发射器的示例。

IFC2x2中增加的新实体。

#	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
IfcLightSourceGoniometric
5	Position	IfcAxis2Placement3D	[1:1]	The position of the light source. It is used to orientate the light distribution curves.	X
6	ColourAppearance	IfcColourRgb	[0:1]	Artificial light sources are classified in terms of their color appearance. To the human eye they all appear to be white; the difference can only be detected by direct comparison. Visual performance is not directly affected by differences in color appearance.	X
7	ColourTemperature	IfcThermodynamicTemperatureMeasure	[1:1]	The color temperature of any source of radiation is defined as the temperature (in Kelvin) of a black-body or Planckian radiator whose radiation has the same chromaticity as the source of radiation. Often the values are only approximate color temperatures as the black-body radiator cannot emit radiation of every chromaticity value. The color temperatures of the commonest artificial light sources range from less than 3000K (warm white) to 4000K (intermediate) and over 5000K (daylight).	X
8	LuminousFlux	IfcLuminousFluxMeasure	[1:1]	Luminous flux is a photometric measure of radiant flux, i.e. the volume of light emitted from a light source. Luminous flux is measured either for the interior as a whole or for a part of the interior (partial luminous flux for a solid angle). All other photometric parameters are derivatives of luminous flux. Luminous flux is measured in lumens (lm). The luminous flux is given as a nominal value for each lamp.	X
9	LightEmissionSource	IfcLightEmissionSourceEnum	[1:1]	Identifies the types of light emitter from which the type required may be set.	X
10	LightDistributionDataSource	IfcLightDistributionDataSourceSelect	[1:1]	The data source from which light distribution data is obtained.	X

 

EXPRESS Specification

ENTITY IfcLightSourceGoniometric
 SUBTYPE OF (IfcLightSource);
  Position : IfcAxis2Placement3D;
  ColourAppearance : OPTIONAL IfcColourRgb;
  ColourTemperature : IfcThermodynamicTemperatureMeasure;
  LuminousFlux : IfcLuminousFluxMeasure;
  LightEmissionSource : IfcLightEmissionSourceEnum;
  LightDistributionDataSource : IfcLightDistributionDataSourceSelect;
END_ENTITY;