.TH OFFSET
 6 "IRIT Version 6.0" 
.SH NAME
OFFSET



 CurveType OFFSET( CurveType Crv, NumericType OffsetDistance,
                   NumericType Tolerance, NumericType BezInterp )

 or

 SurfaceType OFFSET( SurfaceType Srf, NumericType OffsetDistance,
                     NumericType Tolerance, NumericType BezInterp )

 or

 TrimSrfType OFFSET( TrimSrfType TrimSrf, NumericType OffsetDistance,
                     NumericType Tolerance, NumericType BezInterp )

Offsets Crv, Srf or a TrimSrf, by translating all the
control points in the direction of the normal of the curve or the (trimmed)
surface by an OffsetDistance amount.
Each control point has a node parameter value associated with
it, which is used to compute the normal. The returned curve or surface only
approximates the real offset. If the resulting approximation does not satisfy
the accuracy required by Tolerance, Crv or Srf or
TrimSrf is subdivided and an offset approximation fit is computed to
the two halfs. For curves, one can request a Bezier interpolation scheme in
the offset approximation by setting BezInterp. The BezInterp is
not supported yet for (trimmed) surfaces.
Negative OffsetDistance denotes offset in the reversed direction of the
normal.

Example:

    OffCrv = OFFSET( Crv, -0.4, 0.1, off );

offsets Crv by the amount of -0.4 in the reversed normal direction,
Tolerance of 0.1 and no Bezier interpolation.
See also AOFFSET and LOFFSET.