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unit-normal

function unitNormal(ps: number[][], t: number): number[] | undefined

Defined in local-properties-at-t/normal/double/unit-normal.ts:19

Returns the unit normal vector of a bezier curve at a specific given parameter value t (the tangent at that point rotated by 90 degrees and normalized).

  • uses double precision calculations internally
  • returns undefined if the tangent vanishes at t (e.g. at a cusp) since the curve has no well-defined direction there

Parameters:

NameTypeDescription
psnumber[][]a linear, quadratic or cubic bezier curve given by its ordered control points, e.g. [[0,0],[1,1],[2,1],[2,0]]
tnumberthe parameter value where the normal should be evaluated