IFC 4.3.x development IfcMaterialDefinitionRepresentation

Change log








deletionswhere_rulesOnlyStyledRepresentations Semantic definitions at the entity

IfcMaterialDefinitionRepresentation defines presentation information relating to IfcMaterial. It allows for multiple presentations of the same material for different geometric representation contexts.

NOTE  The IfcMaterialDefinitionRepresentation is currently only used to define presentation information to material used at element occurrences, defined as subtypes of IfcElement, or at element types, defined as subtypes of IfcElementType. The IfcMaterial is assigned to the subtype of IfcElement, or IfcElementType using the IfcRelAssociatesMaterial relationship (eventually via other material related entities IfcMaterialLayerSetUsage, IfcMaterialLayerSet, IfcMaterialLayer, or IfcMaterialProfileSetUsage, IfcMaterialProfileSet, IfcMaterialProfile).

The IfcMaterialDefinitionRepresentation can apply

  • different presentation styles for different representation contexts, for example, a different style for sketch view, model view or plan view, or for different target scales,
  • for each representation context is can apply curve style, fill area style (hatching), symbol, text and surface style.

HISTORY  New entity in IFC2x3.

IFC2x3 CHANGE  The entity IfcMaterialDefinitionRepresentation has been added. Upward compatibility for file based exchange is guaranteed.

IFC4 CHANGE  The assignment of curve, surface and other styles to an IfcStyledItem has been simplified by IfcStyleAssignmentSelect. The use of intermediate IfcPresentationStyleAssignment is deprecated.


Use definition

use diagram As shown in Figure 1, the presentation assignment can be specific to a representation context by adding one and more IfcStyledRepresentation's. Each of them includes a single IfcStyledItem with exactly zero or one style for either curve, fill area, surface, text or symbol style that is applicable.

Figure 1 — Material definition representation Attributes

#Attribute Type Description
1Name OPTIONAL IfcLabel The word or group of words by which the product representation is known.
2Description OPTIONAL IfcText The word or group of words that characterize the product representation. It can be used to add additional meaning to the name of the product representation.
3Representations LIST [1:?] OF IfcRepresentationContained list of representations (including shape representations). Each member defines a valid representation of a particular type within a particular representation context.
4RepresentedMaterialIfcMaterial Reference to the material to which the representation applies. Entity inheritance

dot_inheritance IfcMaterialDefinitionRepresentation IfcMaterialDefinitionRepresentation IfcProductRepresentation IfcProductRepresentation IfcMaterialDefinitionRepresentation->IfcProductRepresentation IfcProductDefinitionShape IfcProductDefinitionShape IfcProductDefinitionShape->IfcProductRepresentation Formal representations

ENTITY IfcMaterialDefinitionRepresentation
 SUBTYPE OF (IfcProductRepresentation);
	RepresentedMaterial : IfcMaterial;
	OnlyStyledRepresentations : SIZEOF(QUERY(temp <* Representations | 
)) = 0;