IFC 4.3.x development

8.12.3.2 IfcColourRgb

8.12.3.2.1 Semantic definitions at the entity

NOTE  Definition according to ISO/CD 10303-46:1992
A colour rgb as a subtype of colour specifications is defined by three colour component values for red, green, and blue in the RGB colour model.

NOTE  In contrary to the usual value range of colour components being integer from 0...255, the definition from ISO10303-46 defines the colour components as real from 0.0 ... 1.0. Applications need to execute this conversion before populating the colour RGB values.

NOTE  Corresponding STEP name: colour_rgb. The name attribute has been omitted, the data type for the reg, green and blue parts is IfcNormalizedRatioMeasure, that already includes the range restrictions for the values. Please refer to ISO/IS 10303-46:1994, p. 138 for the final definition of the formal standard.

HISTORY  New entity in IFC2x2.

8.12.3.2.1 Attributes

#Attribute Type Description
IfcPresentationItem
IfcColourSpecification
1Name OPTIONAL IfcLabel 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.

> IFC2x3 CHANGE  Attribute added.
IfcColourRgb
2Red IfcNormalisedRatioMeasureThe 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.
3Green IfcNormalisedRatioMeasureThe 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.
4Blue IfcNormalisedRatioMeasureThe 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.

8.12.3.2.2 Entity inheritance

dot_inheritance IfcColourRgb IfcColourRgb IfcColourSpecification IfcColourSpecification IfcColourRgb->IfcColourSpecification IfcPresentationItem IfcPresentationItem IfcColourSpecification->IfcPresentationItem IfcPresentationItem_children 16 more... IfcPresentationItem_children->IfcPresentationItem

8.12.3.2.3 Formal representations

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