API Reference > geometry-core > Curve > CurvePrimitive > fractionToPointAndUnitTangent fractionToPointAndUnitTangent Method Returns a ray whose origin is the curve point and direction is the unit tangent. fractionToPointAndUnitTangent(fraction: number, result?: Ray3d): Ray3d Parameter Type Description fraction number fractional position on the curve result Ray3d optional preallocated ray. Returns - Ray3d Defined in curve/CurvePrimitive.ts Line 126 Last Updated: 11 June, 2024