This constructor is used to create an Ellipse using the values passed in. The center, unitNormal and majorAxis are used to calculate the start point. The majorAxis vector represents half the major axis of the ellipse (that is, from the center point to the start point of the ellipse) and is the zero angle for startAngle and endAngle. Positive angles are counter-clockwise when looking down the normal vector (that is, right-hand rule). A startAngle of 0 and endAngle of 2pi will produce a closed Ellipse. 

radiusRatio must be in the range 1E-6 to 1.0. 

The dot product of unitNormal with itself and majorAxis with itself must be greater than 1E-12. 

majorAxis must perpendicular to normal within 1E-6. 

The difference between startAngle and endAngle must be greater than 1E-6. 

If any of the parameters are not acceptable, then the gelib object for the Ellipse will not be created and this constructor will behave like the default constructor (that is, the passed in values will not be used and the data query methods on the Ellipse will return invalid values). 

The isNull property can be used to determine if this constructor succeeded in initializing the Ellipse to the values passed in. If isNull is false, then the initialization succeeded.

Public Sub New(
    center As Point3d, 
    unitNormal As Vector3d, 
    majorAxis As Vector3d, 
    radiusRatio As double, 
    startAngle As double, 
    endAngle As double
)

public Ellipse(
    Point3d center, 
    Vector3d unitNormal, 
    Vector3d majorAxis, 
    double radiusRatio, 
    double startAngle, 
    double endAngle
);