 | Oberfl盲chenbearbeitung |
 | Surface Feature |
 | Traitement de surface |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 |
|---|---|---|---|---|
| IfcSurfaceFeature | ADDED | IFC4 Addendum 1 | ||
| IfcSurfaceFeature | ||||
| HasCoverings | ADDED |
A surface feature is a modification at (onto, or into) of the surface of an element. Parts of the surface of the entire surface may be affected. The volume and mass of the element may be increased, remain unchanged, or be decreased by the surface feature, depending on manufacturing technology. However, any increase or decrease of volume is small compared to the total volume of the element.
The standard use of instances of IfcSurfaceFeature is as a part of element type objects (instances of subtypes of IfcElementType). The part–whole relationship is established by an aggregation relationship object, expressing the decomposition of an element type into one or more additive elements (element parts) and zero or more feature elements.
HISTORY New entity in IFC4.
Containment Use Definition:
Surface features shall have no spatial containment relationship to the spatial structure since they are dependent on element types without spatial containment relationships or on an element occurrence with own spatial containment relationship.
Geometry use definition:
The geometric representation of IfcSurfaceFeatureElement is given by the IfcProductDefinitionShape, allowing multiple geometric representation.
Local Placement
The local placement for IfcSurfaceFeatureElement is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.
Shape representation
Different shape representations may be used, depending on the nature of the feature and information requirements:
Higher-level parameters (geometric and non-geometric) may be provided by property sets based on local agreements.
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| 9 | PredefinedType | IfcSurfaceFeatureTypeEnum | ? | Indicates the kind of surface feature. | X |
| Rule | Description |
|---|---|
| HasObjectType | The attribute ObjectType shall be given if the predefined type is set to USERDEFINED. |
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| IfcRoot | |||||
| 1 | GlobalId | IfcGloballyUniqueId | Assignment of a globally unique identifier within the entire software world. | X | |
| 2 | OwnerHistory | IfcOwnerHistory | ? |
Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,
NOTE only the last modification in stored - either as addition, deletion or modification. IFC4 CHANGE The attribute has been changed to be OPTIONAL. | X |
| 3 | Name | IfcLabel | ? | Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. | X |
| 4 | Description | IfcText | ? | Optional description, provided for exchanging informative comments. | X |
| IfcObjectDefinition | |||||
| HasAssignments | IfcRelAssigns @RelatedObjects | S[0:?] | Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups. | X | |
| Nests | IfcRelNests @RelatedObjects | S[0:1] | References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition. | X | |
| IsNestedBy | IfcRelNests @RelatingObject | S[0:?] | References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).
IFC4 CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition. | X | |
| HasContext | IfcRelDeclares @RelatedDefinitions | S[0:1] | References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.
IFC4 CHANGE The inverse attribute datatype has been added. | X | |
| IsDecomposedBy | IfcRelAggregates @RelatingObject | S[0:?] | References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).
IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates. | X | |
| Decomposes | IfcRelAggregates @RelatedObjects | S[0:1] | References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates. | X | |
| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification. | X | |
| IfcObject | |||||
| 5 | ObjectType | IfcLabel | ? |
The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
| X |
| IsDeclaredBy | IfcRelDefinesByObject @RelatedObjects | S[0:1] | Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange. | X | |
| Declares | IfcRelDefinesByObject @RelatingObject | S[0:?] | Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE New inverse relationship, change made with upward compatibility for file based exchange. | X | |
| IsTypedBy | IfcRelDefinesByType @RelatedObjects | S[0:1] | Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.
IFC4 CHANGE New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange. | X | |
| IsDefinedBy | IfcRelDefinesByProperties @RelatedObjects | S[0:?] | Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.
IFC4 CHANGE The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange. | X | |
| IfcProduct | |||||
| 6 | ObjectPlacement | IfcObjectPlacement | ? | Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system. | X |
| 7 | Representation | IfcProductRepresentation | ? | Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement. | X |
| ReferencedBy | IfcRelAssignsToProduct @RelatingProduct | S[0:?] | Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product. | X | |
| IfcElement | |||||
| 8 | Tag | IfcIdentifier | ? | The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrence level. | X |
| FillsVoids | IfcRelFillsElement @RelatedBuildingElement | S[0:1] | Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element. | X | |
| ConnectedTo | IfcRelConnectsElements @RelatingElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to. | X | |
| IsInterferedByElements | IfcRelInterferesElements @RelatedElement | S[0:?] | Reference to the interference relationship to indicate the element that is interfered. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements. IFC4 CHANGE New inverse relationship. | X | |
| InterferesElements | IfcRelInterferesElements @RelatingElement | S[0:?] | Reference to the interference relationship to indicate the element that interferes. The relationship, if provided, indicates that this element has an interference with one or many other elements.
NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements. IFC4 CHANGE New inverse relationship. | X | |
| HasProjections | IfcRelProjectsElement @RelatingElement | S[0:?] | Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement. | X | |
| ReferencedInStructures | IfcRelReferencedInSpatialStructure @RelatedElements | S[0:?] | Reference relationship to the spatial structure element, to which the element is additionally associated. This relationship may not be hierarchical, an element may be referenced by zero, one or many spatial structure elements.
IFC2x3 CHANGE The inverse attribute has been added with upward compatibility for file based exchange. | X | |
| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the IfcRelVoidsElement relationship that creates an opening in an element. An element can incorporate zero-to-many openings. For each opening, that voids the element, a new relationship IfcRelVoidsElement is generated. | X | |
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship, if provided, assigns this element as the realizing element to the connection, which provides the physical manifestation of the connection relationship. | X | |
| ProvidesBoundaries | IfcRelSpaceBoundary @RelatedBuildingElement | S[0:?] | Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces. | X | |
| ConnectedFrom | IfcRelConnectsElements @RelatedElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element. | X | |
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated. This containment relationship has to be hierachical, i.e. an element may only be assigned directly to zero or one spatial structure. | X | |
| HasCoverings | IfcRelCoversBldgElements @RelatingBuildingElement | S[0:?] | Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated. | X | |
| IfcFeatureElement | |||||
| IfcSurfaceFeature | |||||
| 9 | PredefinedType | IfcSurfaceFeatureTypeEnum | ? | Indicates the kind of surface feature. | X |
Property Sets
The Property Sets for Objects concept template applies to this entity as shown in Table 662.
Placement
The Product Local Placement concept template applies to this entity as shown in Table 663.
| ||||||
Table 663 — IfcSurfaceFeature Product Local Placement |
The local placement for IfcSurfaceFeatureElement is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.
Body Geometry
The Body Geometry concept template applies to this entity as shown in Table 664.
| ||
Table 664 — IfcSurfaceFeature Body Geometry |
Instance diagram
<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="0363f51c-a75e-4935-b594-4295c56815b0" name="IfcSurfaceFeature" status="sample" applicableRootEntity="IfcSurfaceFeature">
<Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
<Template ref="05c1e221-7eb8-4101-b904-dbbd7a288d8a" />
<TemplateRules operator="and" />
</Applicability>
<Concepts>
<Concept uuid="08d33b0b-77a1-48af-8a04-e9e86e8fd8da" name="Property Sets" status="sample" override="false">
<Template ref="f74255a6-0c0e-4f31-84ad-24981db62461" />
</Concept>
<Concept uuid="55f870ed-e0fd-428a-ae1f-b7ad809a2d71" name="Placement" status="sample" override="false">
<Template ref="cbe85b5f-7912-4a43-8bb7-1e63bf40b26d" />
</Concept>
<Concept uuid="9d94eaf1-8f5c-4519-a035-cc1a3e12d5c6" name="Body Geometry" status="sample" override="false">
<Template ref="c446bd16-2de3-4b97-b34f-4446ac0badc2" />
<TemplateRules operator="and">
<TemplateRule Description="Surface representations of treated parts of the lement surface by means of <em>IfcShellBasedSurfaceModel</em>. The faces within the surface model may be included into a B-Rep model within a representation map of the parent element type." Parameters="" />
</TemplateRules>
</Concept>
</Concepts>
</ConceptRoot>
| # | Concept | Template | Model View |
|---|---|---|---|
| IfcRoot | |||
| Identity | Software Identity | General Usage | |
| Revision Control | Revision Control | General Usage | |
| IfcObjectDefinition | |||
| Classification Association | Classification Association | General Usage | |
| IfcObject | |||
| Object User Identity | Object User Identity | General Usage | |
| Object Predefined Type | Object Predefined Type | General Usage | |
| Object Typing | Object Typing | General Usage | |
| Property Sets with Override | Property Sets with Override | General Usage | |
| IfcProduct | |||
| Product Placement | Product Placement | General Usage | |
| Product Geometric Representation | Product Geometric Representation | General Usage | |
| IfcElement | |||
| CoG Geometry | CoG Geometry | General Usage | |
| Box Geometry | Box Geometry | General Usage | |
| FootPrint Geometry | FootPrint Geometry | General Usage | |
| Body SurfaceOrSolidModel Geometry | Body SurfaceOrSolidModel Geometry | General Usage | |
| Body SurfaceModel Geometry | Body SurfaceModel Geometry | General Usage | |
| Body Tessellation Geometry | Body Tessellation Geometry | General Usage | |
| Body Brep Geometry | Body Brep Geometry | General Usage | |
| Body AdvancedBrep Geometry | Body AdvancedBrep Geometry | General Usage | |
| Body CSG Geometry | Body CSG Geometry | General Usage | |
| Mapped Geometry | Mapped Geometry | General Usage | |
| Element Voiding | Element Voiding | General Usage | |
| Element Projecting | Element Projecting | General Usage | |
| IfcFeatureElement | |||
| Spatial Containment | Spatial Containment | General Usage | |
| IfcSurfaceFeature | |||
| Property Sets | Property Sets for Objects | General Usage | |
| Placement | Product Local Placement | General Usage | |
| Body Geometry | Body Geometry | General Usage | |
<xs:element name="IfcSurfaceFeature" type="ifc:IfcSurfaceFeature" substitutionGroup="ifc:IfcFeatureElement" nillable="true"/>
<xs:complexType name="IfcSurfaceFeature">
<xs:complexContent>
<xs:extension base="ifc:IfcFeatureElement">
<xs:attribute name="PredefinedType" type="ifc:IfcSurfaceFeatureTypeEnum" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcSurfaceFeature
SUBTYPE OF (IfcFeatureElement);
PredefinedType : OPTIONAL IfcSurfaceFeatureTypeEnum;
WHERE
HasObjectType : NOT EXISTS(PredefinedType) OR (PredefinedType <> IfcSurfaceFeatureTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
END_ENTITY;
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