8.9.2.12 IfcTransitionCode

8.9.2.12.1 Semantic definition

IfcTransitionCode indicates the continuity between consecutive segments of a curve or surface.

Figure A illustrates transition types

{ .extDef}

Type	Description
`CONTINUOUS`	The segments join but no condition on their tangents is implied.
`CONTSAMEGRADIENT`	The segments join and their tangent vectors or tangent planes are parallel and have the same direction at the joint: equality of derivatives is not required.
`CONTSAMEGRADIENTSAMECURVATURE`	For a curve, the segments join, their tangent vectors are parallel and in the same direction and their curvatures are equal at the joint: equality of derivatives is not required. For a surface this implies that the principle curvatures are the same and the principle directions are coincident along the common boundary.
`DISCONTINUOUS`	The segments do not join. This is permitted only at the boundary of the curve or surface to indicate that it is not closed.

Table B

TYPE IfcTransitionCode = ENUMERATION OF
(CONTINUOUS
,CONTSAMEGRADIENT
,CONTSAMEGRADIENTSAMECURVATURE
,DISCONTINUOUS);
END_TYPE;