5.4.2.13 IfcGridTypeEnum

5.4.2.13.1 Semantic definition

This enumeration defines the different layout types of grids. Restriction on the correct use of IfcGrid instantiations may be imposed depending on the value of the PredefinedType being IfcGridTypeEnum.

5.4.2.13.2 Type values

Type	Description
`IRREGULAR`	An IfcGrid with u-axes, v-axes, and optionally w-axes that cannot be described by the patterns.
`RADIAL`	An IfcGrid with straight u-axes and curved v-axes. All grid axes being part of V-axes have the same center point and are concentric circular arcs. All grid axes being part of u-axes intersect at the same center point and rotate counter clockwise.
`RECTANGULAR`	An IfcGrid with straight u-axes and straight v-axes being perpendicular to each other. All grid axes being part of u-axes can be described by one axis line and all other axes being 2D offsets from this axis line. The same applies to all grid axes being part of V-axes.
`TRIANGULAR`	An IfcGrid with u-axes, v-axes, and w-axes all being co-linear axis lines with a 2D offset. The v-axes are at 60 degree rotated counter clockwise from the u-axes, and the w-axes are at 120 degree rotated counter clockwise from the u-axes.
`USERDEFINED`	Any other grid not conforming to any of the above restrictions.
`NOTDEFINED`	Not known whether grid conforms to any standard type.

Table 5.4.2.13.A

5.4.2.13.3 Formal representation

TYPE IfcGridTypeEnum = ENUMERATION OF
	(IRREGULAR
	,RADIAL
	,RECTANGULAR
	,TRIANGULAR
	,USERDEFINED
	,NOTDEFINED);
END_TYPE;

5.4.2.13.4 References

IfcGrid