Function Curve3D.interpolateBakedUpVector

Returns an up vector within the curve at position offset, where offset is measured as a distance in 3D units along the curve. To do that, it finds the two cached up vectors where the offset lies between, then interpolates the values. If apply_tilt is true, an interpolated tilt is applied to the interpolated up vector. If the curve has no up vectors, the function sends an error to the console, and returns (0, 1, 0).

Vector3 interpolateBakedUpVector (
  const(double) offset,
  const(bool) apply_tilt = false
) nothrow @nogc const;