fractionToPointAndDerivative Method

Return the point (x,y,z) and derivative on the curve at fractional position.

• Note that the derivative is "derivative of xyz with respect to fraction".
• The derivative shows the speed of the "fractional point" moving along the curve.
• The derivative is not generally a unit vector. Use fractionToPointAndUnitTangent for a unit vector.

fractionToPointAndDerivative(fraction: number, result?: Ray3d): Ray3d

@returns a ray whose origin is the curve point and direction is the derivative with respect to the fraction. If the chain is empty, a zero ray is returned.

Returns - Ray3d

a ray whose origin is the curve point and direction is the derivative with respect to the fraction. If the chain is empty, a zero ray is returned.

Defined in

• curve/CurveChainWithDistanceIndex.ts Line 592