8.9.2.12 IfcTransitionCode
8.9.2.12.1 Semantic definition
The IfcTransitionCode indicated the continuity between consecutive segments of a curve or surface.
Figure 8.9.2.12.A illustrates transition types
8.9.2.12.2 Type values
| 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. |
8.9.2.12.3 Formal representation
TYPE IfcTransitionCode = ENUMERATION OF
(CONTINUOUS
,CONTSAMEGRADIENT
,CONTSAMEGRADIENTSAMECURVATURE
,DISCONTINUOUS);
END_TYPE;