The planar surface is an unbounded surface in the direction of x and y. Bounded planar surfaces are defined by using a subtype of IfcBoundedSurface with BasisSurface being a plane.
NOTE Definition according to ISO/CD 10303-42:1992
A plane is an unbounded surface with a constant normal. A plane is defined by a point on the plane and the normal direction to the plane. The data is to be interpreted as follows:C = Position.Location x = Position.P y = Position.P z = Position.P => normal to planeand the surface is parameterized as:
where the parametric range is -∞ < u,v < ∞. In the above parameterization the length unit for the unit vectors x and y is derived from the context of the plane.
NOTE A rectangular bounded planar surface can be defined by an IfcRectangularTrimmedSurface with BasisSurface being the plane and U1 = left bound in x, U2 = right bound in x, V_1 = lower bound in y, _V2 = upper bound in y if viewed into the direction of the negative normal. (assuming the Usense and Vsense agree to the sense of the basis surface).
The inherited attributes are interpreted as
NOTE Entity adapted from plane in ISO 10303-42.
HISTORY New entity in IFC1.5
|LayerAssignment||SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems||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.|
> IFC2x3 CHANGE The inverse attribute LayerAssignments has been added.
> IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.
|StyledByItem||SET [0:1] OF IfcStyledItem FOR Item||Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.|
> IFC2x3 CHANGE The inverse attribute StyledByItem has been added.
|Dim||INVALID||The space dimensionality of IfcSurface. It is always a three-dimensional geometric representation item.|
> IFC4 CHANGE Derived attribute promoted from subtypes.
|1||Position||IfcAxis2Placement3D||The position and orientation of the surface. This attribute is used in the definition of the parameterization of the surface.|
ENTITY IfcPlane SUBTYPE OF (IfcElementarySurface); END_ENTITY;