API Reference > geometry-core > Serialization > IModelJson > IModelJson.TransitionSpiralProps > intervalFractions intervalFractions intervalFractions: undefined | [number, number] A fractional portion of the spiral may be selected. If this is missing, fraction range is [0,1] Defined in core/geometry/src/serialization/IModelJsonSchema.ts Line 332 Last Updated: 13 June, 2024