API Reference > geometry-core > 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: undefined | number, radius1: undefined | number, bearing0: undefined | Angle, bearing1: undefined | Angle, arcLength: undefined | number): TransitionConditionalProperties capture numeric or undefined values applyScaleFactor(a: number): void Apply a NONZERO scale factor to all distances. clone(): TransitionConditionalProperties clone with all properties (i.e. getIsValidCompleteSet(): boolean Return true if all components 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: undefined | TransitionConditionalProperties, b: undefined | TransitionConditionalProperties): boolean Static Properties Name Type Description bearing0 undefined | Angle bearing at start, measured from x towards y bearing1 undefined | Angle bearing at end, measured from x towards y curveLength undefined | number curve length radius0 undefined | number radius (or 0 at start) radius1 undefined | number radius (or 0) at end Defined in curve/spiral/TransitionConditionalProperties.ts Line 24 Last Updated: 12 June, 2024