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IArcSpline3DCurve Interface

GetSplineNormals
GetCurvatureArray
GetSpline
MakeSmoothModifyCurvatures
MakeSmoothAlternating

IArcSpline3DCurve gives programmatic access to Arc Spline Curves. Objects implementing this interface also implement ICurveFreeForm

See also Pipes sampleInterface List


HRESULT GetSplineNormals(IArray3D** normals)

Parameters

normals - [out, retval] The retuned array of spline normals. i-th element in the array in a normal vector of plane of i-th spline.

Remarks:

Returns array of spline normals. i-th element in the array in a normal vector of plane of i-th spline.


HRESULT GetCurvatureArray(IArrayNum** curvatures)

Parameters

curvatures - [out, retval] array of curvatures one per spline

Remarks:

The method returns array of double numbers one per spline in the curve. The i-th number is curvature of i-th spline arc. IArrayNum.Set will fail with DISP_E_PARAMNOTOPTIONAL return if the curvature is too high and the arc would become invalid (geometrically impossible).


HRESULT GetSpline(int index, IArc** iArc)

Parameters

index - [in] Index of the spline to be retrieved

Remarks:

Use this method to access more advanced properties of an individual spline in the curve.


HRESULT MakeSmoothModifyCurvatures()

Modifies spline normals and curvatures to make the whole curve smoothely interpolating the input points


HRESULT MakeSmoothAlternating(double curvature)

Assumes that on start the points data is already defined (see ICurveFreeForm) and the first entity is straight. Modifies spline normals of every second entity and sets its curvature to curvature so that the resulting curve is smooth. Points are also shifted along the previous straight entity to make this possible. In case when two consequtive straight entities do not belong to a single plane an additional point is inserted and a two-arc spline is constructed to smoothely connect the straight entities