# 8.14.2.3 IfcLightDistributionDataSourceSelect

## 8.14.2.3.1 Semantic definition

A goniometric light gets its intensity distribution function (how much light goes in any one direction) from one of two sources: (i) an industry-standard file, (ii) from distribution data passed directly via the IfcLightIntensityDistribution.

The light distribution provides the luminous intensity distribution according to some standardized light distribution curves.

## 8.14.2.3.3 Formal representation

TYPE IfcLightDistributionDataSourceSelect = SELECT
(IfcExternalReference
,IfcLightIntensityDistribution);
END_TYPE;