API Reference › core-geometry› Curve › TransitionConditionalProperties

TransitionConditionalProperties Class

A true transition spiral is a curve defined by its curvature, with the curvature function symmetric about midpoint.

  • The symmetry condition creates a relationship among the following 4 quantities: ** curvature0 = curvature (i.e. 1/radius) at start. ** curvature1 = curvature (i.e. 1/radius) at end. ** sweepRadians = signed turning angle from start to end. ** arcLength = length of curve.
  • The relationship is the equation: ** sweepRadians = arcLength * average Curvature = arcLength * 0.5 * (curvature0 + curvature1)
  • That is, regardless of any curvature properties other than symmetry, specifying any 3 of the quantities fully determines the remaining one.

Methods

Name Description
constructor(radius0: number, radius1: number, bearing0: Angle, bearing1: Angle, arcLength: number): TransitionConditionalProperties Capture numeric or undefined values.  
applyScaleFactor(a: number): void Apply a NONZERO scale factor to all distances.  
clone(): TransitionConditionalProperties Clone with all 5 properties (i.e., preserve undefined states).  
getIsValidCompleteSet(): boolean Return true if all 5 properties are defined and agree equationally.  
isAlmostEqual(other?: TransitionConditionalProperties): boolean Test if this and other have matching numeric and undefined members.  
numDefinedProperties(): number Return the number of defined values among the 5 properties.  
tryResolveAnySingleUnknown(): boolean Examine which properties are defined and compute the (single) undefined.  
areAlmostEqual(a: TransitionConditionalProperties, b: TransitionConditionalProperties): boolean Static Test if a and b have matching numeric and undefined members.  

Properties

Name Type Description
bearing0 undefined | Angle Bearing at start (the signed angle from global x-axis to the start tangent of the spiral).  
bearing1 undefined | Angle Bearing at end (the signed angle from global x-axis to the end tangent of the spiral).  
curveLength undefined | number Curve length.  
radius0 undefined | number Radius at start (radius of the osculating circle at the spiral segment's start).  
radius1 undefined | number Radius at end (radius of the osculating circle at the spiral segment's end).  

Defined in

Last Updated: 28 October, 2025