IfcLightSourceGoniometric

Definition from IAI: The IfcLightSourceGoniometric defines a light source for which exact lighting data is available. It specifies the type of a light emitter, defines the position and orientation of a light distribution curve and the data concerning lamp and photometric information.

Illustration:

Example of a light emitter having two light sources (of type IfcLightSourceGoniometric).

> HISTORY: New entity in Release IFC2x Edition 2.

EXPRESS specification:

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

Attribute definitions:

Position | : | The position of the light source. It is used to orientate the light distribution curves.
ColourAppearance | : | 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.
ColourTemperature | : | 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).
LuminousFlux | : | 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.
LightEmissionSource | : | Identifies the types of light emitter from which the type required may be set.
LightDistributionDataSource | : | The data source from which light distribution data is obtained.

Inheritance graph

ENTITY IfcLightSourceGoniometric;
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;
ENTITY IfcLightSourceGoniometric;
Position | : | IfcAxis2Placement3D;
ColourAppearance | : | OPTIONAL IfcColourRgb;
ColourTemperature | : | IfcThermodynamicTemperatureMeasure;
LuminousFlux | : | IfcLuminousFluxMeasure;
LightEmissionSource | : | IfcLightEmissionSourceEnum;
LightDistributionDataSource | : | IfcLightDistributionDataSourceSelect;
END_ENTITY;