Spline VEX node

Computes either a Catmull-Rom (Cardinal) spline or a Linear spline between the spec…

See also: Blend Regions, Color Mix, Fire, Mix 2 more , , Smooth

This operator computes either a Catmull-Rom (Cardinal) spline or a Linear spline between the specified key points, given an interpolant (u) in the domain of the spline. The result is a 1D, 3D, or 4D value representing u’s image on the spline.

The Cardinal keys are uniformly spaced over the range 0 to 1. Because of the nature of the Cardinal spline, the value associated with the first and last keys will never be returned. However, these keys are used to determine the shape of the curve on entry and exit. If you want the spline to reach its end points, connect the first key and last key twice. See the Fire operator for one such example.

If you are blending only two vector types using the Cardinal interpolant, the Color Mix operator offers the convenience of fewer connections. Make sure, however, that you choose the “Smooth With Cardinal Spline” option to obtain the exact same results as with this operator.

The Linear spline interpolation is equivalent to a sequence of Linear Interpolation operators. Consider the simpler Mix operator if only two inputs are required.