注：定义符合ISO/CD 10303-46:1992

颜色rgb作为颜色规格的一个子类型，由rgb颜色模型中红色、绿色和蓝色的三个颜色分量值定义。

注：与通常颜色分量的值范围为0…255之间的整数相反，ISO10303-46中的定义将颜色分量定义为0.0…255之间的实数。。。1.0. 应用程序需要在填充颜色RGB值之前执行此转换。

注意对应的步骤名称：colour\u rgb。name属性已被省略，reg、green和blue部分的数据类型为IfcNormalizedRatioMeasure，它已经包括值的范围限制。正式标准的最终定义请参考ISO/IS 10303-46:1994，第138页。

IFC2x2中增加的新实体。

 

 

 

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcPresentationItem
IfcColourSpecification
1	Name	IfcLabel	[0:1]	Optional name given to a particular colour specification in addition to the colour components (like the RGB values). EXAMPLE  Names of a industry colour classification, such as RAL.	X
IfcColourRgb
2	Red	IfcNormalisedRatioMeasure	[1:1]	The intensity of the red colour component. NOTE  The colour component value is given within the range of 0..1, and not within the range of 0..255 as otherwise usual.	X
3	Green	IfcNormalisedRatioMeasure	[1:1]	The intensity of the green colour component. NOTE  The colour component value is given within the range of 0..1, and not within the range of 0..255 as otherwise usual.	X
4	Blue	IfcNormalisedRatioMeasure	[1:1]	The intensity of the blue colour component. NOTE  The colour component value is given within the range of 0..1, and not within the range of 0..255 as otherwise usual.	X

 

EXPRESS Specification

ENTITY IfcColourRgb
 SUBTYPE OF (IfcColourSpecification);
  Red : IfcNormalisedRatioMeasure;
  Green : IfcNormalisedRatioMeasure;
  Blue : IfcNormalisedRatioMeasure;
END_ENTITY;