Arc Structure

Represents the value of a plane, two angles and a radius in a sub-curve of a three-dimensional circle.

The curve is parameterized by an angle expressed in radians. For an IsValid arc the total subtended angle AngleRadians() = Domain()(1) - Domain()(0) must satisfy 0 < AngleRadians() < 2*Pi

The parameterization of the Arc is inherited from the Circle it is derived from. In particular

t -> center + cos(t)*radius*xaxis + sin(t)*radius*yaxis

where xaxis and yaxis, (part of Circle.Plane) form an orthonormal frame of the plane containing the circle.

Namespace: Rhino.Geometry
Assembly: RhinoCommon (in RhinoCommon.dll)

Syntax

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[SerializableAttribute]
public struct Arc : IEquatable<Arc>, IEpsilonComparable<Arc>, 
	ICloneable

<SerializableAttribute>
Public Structure Arc
	Implements IEquatable(Of Arc), IEpsilonComparable(Of Arc), 
	ICloneable

The Arc type exposes the following members.

Constructors

	Name	Description
	Arc(Circle, Interval)	Initializes a new instance of an arc from a base circle and an interval of angles.
	Arc(Circle, Double)	Initializes a new instance of an arc from a base circle and an angle.
	Arc(Plane, Double, Double)	Initializes a new arc from a base plane, a radius value and an angle.
	Arc(Point3d, Point3d, Point3d)	Initializes a new arc through three points. If the points are coincident or co-linear, this will result in an Invalid arc.
	Arc(Point3d, Vector3d, Point3d)	Initializes a new arc from end points and a tangent vector. If the tangent is parallel with the endpoints this will result in an Invalid arc.
	Arc(Point3d, Double, Double)	Initializes a new horizontal arc at the given center point, with a custom radius and angle.
	Arc(Plane, Point3d, Double, Double)	Initializes a new aligned arc at the given center point, with a custom radius and angle.

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Properties

	Name	Description
	Angle	Gets or sets the sweep -or subtended- angle (in Radians) for this arc segment.
	AngleDegrees	Gets or sets the sweep -or subtended- angle (in Degrees) for this arc segment.
	AngleDomain	Gets or sets the angle domain (in Radians) of this arc.
	Center	Gets or sets the center point for this arc.
	Circumference	Gets the circumference of the circle that is coincident with this arc.
	Diameter	Gets or sets the Diameter of this arc.
	EndAngle	Gets or sets the end angle (in Radians) for this arc segment.
	EndAngleDegrees	Gets or sets the end angle (in Degrees) for this arc segment.
	EndPoint	Gets the end point of the arc.
	IsCircle	Gets a value indicating whether or not this arc is a complete circle.
	IsValid	Gets a value indicating whether or not this arc is valid. Detail: Radius>0 and 0<AngleRadians()<=2*Math.Pi.
	Length	Gets the length of the arc. (Length = Radius * (subtended angle in radians)).
	MidPoint	Gets the mid-point of the arc.
	Plane	Gets or sets the plane in which this arc lies.
	Radius	Gets or sets the radius of this arc.
	StartAngle	Gets or sets the start angle (in Radians) for this arc segment.
	StartAngleDegrees	Gets or sets the start angle (in Degrees) for this arc segment.
	StartPoint	Gets the start point of the arc.
	Unset	Gets an Arc with Unset components.

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Methods

	Name	Description
	BoundingBox	Computes the 3D axis aligned bounding box for this arc.
	ClosestParameter	Gets parameter on the arc closest to a test point.
	ClosestPoint	Computes the point on an arc that is closest to a test point.
	EpsilonEquals	Check that all values in other are within epsilon of the values in this
	Equals(Arc)	Determines whether another arc has the same value as this arc.
	Equals(Object)	Determines whether another object is an arc and has the same value as this arc. (Overrides ValueTypeEquals(Object).)
	GetHashCode	Computes a hash code for the present arc. (Overrides ValueTypeGetHashCode.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	PointAt	Gets the point at the given arc parameter.
	Reverse	Reverses the orientation of the arc. Changes the domain from [a,b] to [-b,-a].
	TangentAt	Gets the tangent at the given parameter.
	ToNurbsCurve	Initializes a nurbs curve representation of this arc. This amounts to the same as calling NurbsCurve.CreateFromArc().
	ToNurbsCurve(Int32, Int32)	Create a uniform non-rational cubic NURBS approximation of an arc.
	ToString	Returns the fully qualified type name of this instance. (Inherited from ValueType.)
	Transform	Transforms the arc using a Transformation matrix.
	Trim	Sets arc's angle domain (in Radians) as a sub-domain of the circle.

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Operators

	Name	Description
	Equality	Determines whether two arcs have equal values.
	Inequality	Determines whether two arcs have different values.

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Reference

Rhino.Geometry Namespace