API Reference > geometry-core > Bspline > BSpline1dNd > evaluateBuffersInSpan evaluateBuffersInSpan Method Evaluate the basis functions at spanIndex and fraction. Evaluations are stored in the preallocated this.basisBuffer Immediately do the summations of the basis values times the respective control points Summations are stored in the preallocated this.poleBuffer evaluateBuffersInSpan(spanIndex: number, spanFraction: number): void Parameter Type Description spanIndex number spanFraction number Returns - void Defined in core/geometry/src/bspline/BSpline1dNd.ts Line 103 Last Updated: 15 June, 2021