IfcBlock

Natural language names
deQuader
enBlock
frParallélépipède
Semantic definitions at the entity
Entity definition

The IfcBlock is a Construction Solid Geometry (CSG) 3D primitive. It is defined by a position and a positve distance along the three orthogonal axes. The inherited Position attribute has the IfcAxisPlacement3D type and provides:

The XLength, YLength, and ZLength attributes define the size of the IfcBlock along the three axes.

block

Figure 307 illustrates geometric parameters of a block where the block positioned within its own placement coordinate system. The values for XLength, YLength, and ZLength are applied to the positive direction of the X, Y, and Z axis.

Figure 307 — Block geometry

 
NOTE  Definition according to ISO/CD 10303-42:1992
A block is a solid rectangular parallelepiped, defined with a location and placement coordinate system. The block is specified by the positive lengths x, y, and z along the axes of the placement coordinate system, and has one vertex at the origin of the placement coordinate system.
NOTE  Entity adapted from block defined in ISO 10303-42.
HISTORY  New entity in IFC2x3.

Texture definition

On each side face, textures are aligned facing upright. On the top and bottom faces, textures are aligned facing front-to-back. Textures are stretched or repeated to the extent of each face according to RepeatS and RepeatT.

Figure 308 illustrates default texture mapping with a clamped texture (RepeatS=False and RepeatT=False). The image on the left shows the texture where the S axis points to the right and the T axis points up. The image on the right shows the texture applied to the geometry where the X axis points back to the right, the Y axis points back to the left, and the Z axis points up.

 

texture
Side Normal Origin X Origin Y Origin Z S Axis T Axis
Left -X 0 +YLength 0 -Y +Z
Right +X +XLength 0 0 +Y +Z
Front -Y 0 0 0 +X +Z
Back +Y +XLength +YLength 0 -X +Z
Bottom -Z 0 +YLength 0 +X -Y
Top +Z 0 0 +ZLength +X +Y

Figure 308 — Block textures

Attribute definitions
#AttributeTypeCardinalityDescription C
2XLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement X axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[1].X
3YLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement Y axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[2].X
4ZLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement Z axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[3].X
Inherited definitions from supertypes
Entity inheritance IfcCsgPrimitive3D IfcGeometricRepresentationItem IfcRepresentationItem
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRepresentationItem
LayerAssignmentIfcPresentationLayerAssignment
@AssignedItems
S[0:1]Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items. X
StyledByItemIfcStyledItem
@Item
S[0:1]Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve. X
IfcGeometricRepresentationItem
IfcCsgPrimitive3D
1PositionIfcAxis2Placement3D[1:1] The placement coordinate system to which the parameters of each individual CSG primitive apply.X
Dim
:=3
IfcDimensionCount[1:1]The space dimensionality of this geometric representation item, it is always 3. X
IfcBlock
2XLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement X axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[1].X
3YLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement Y axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[2].X
4ZLengthIfcPositiveLengthMeasure[1:1] The size of the block along the placement Z axis. It is provided by the inherited axis placement through SELF\IfcCsgPrimitive3D.Position.P[3].X
Examples
Formal representations
XSD Specification
 <xs:element name="IfcBlock" type="ifc:IfcBlock" substitutionGroup="ifc:IfcCsgPrimitive3D" nillable="true"/>
 <xs:complexType name="IfcBlock">
  <xs:complexContent>
   <xs:extension base="ifc:IfcCsgPrimitive3D">
    <xs:attribute name="XLength" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="YLength" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="ZLength" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcBlock
 SUBTYPE OF (IfcCsgPrimitive3D);
  XLength : IfcPositiveLengthMeasure;
  YLength : IfcPositiveLengthMeasure;
  ZLength : IfcPositiveLengthMeasure;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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