Determining the Orientation of the Generatrix

The function

double AreaSign( const MbCurve3D &  curve,
                 const MbAxis3D &   axis,
                 const MbVector3D & direction,
                       bool         rotation )

computes the area of the projection of a curve onto a virtual coordinate plane to determine the orientation of a generatrix curve when subsequently constructing a body by extruding or revolving the generatrix curve. An open generatrix curve is closed by a segment for the calculation.

The input parameters of the function are:

• curve – the generatrix curve;

• axis – the axis of revolution (used for the revolution calculation);

• direction – the extrusion direction (used for the extrusion calculation);

• rotation – the flag specifying the operation type: true for revolution and false for extrusion.

The output of the function is the projection area of the curve.

The function is an auxiliary one for the ExtrusionSolid(), RevolutionSolid(), ExtrusionResult() and RevolutionResult() functions.