Cubic Spline

Functionality

This node generates a cubic spline interpolating curve, i.e. a 3rd degree curve which goes through the specified vertices. The curve can be closed or not.

Curve domain is always from 0 to 1. The parametrization depends on Metrics parameter.

Inputs

This node has the following input:

• Vertices. The points through which it is required to plot the curve. This input is mandatory.

Parameters

This node has the following parameters:

• Cyclic. If checked, the node will generate a cyclic (closed) curve. Unchecked by default.

• Metric. This parameter is available in the N panel only. This defines the metric used to calculate curve’s T parameter values corresponding to specified curve points. The available values are:

  • Manhattan

  • Euclidean

  • Points (just number of points from the beginning)

  • Chebyshev

  • Centripetal (square root of Euclidean distance)

  • X, Y, Z axis - use distance along one of coordinate axis, ignore others.

The default value is Euclidean.

Outputs

This node has the following output:

• Curve. The generated curve.

Examples of usage

Smooth curve through some random points:

• Generator-> Random Vector

• Modifiers->Modifier Make-> UV Connection

• Viz-> Viewer Draw

• Viz-> Viewer Draw Curve

The same with Cyclic checked:

These examples had Metric set to Euclidean (default). Since Eval Curve node generates evenly-distributed values of the T parameter, the number of points at each segment is proportional to the distance between points. The next example is with Metric set to Points:

In this case, number of points at each segment is the same.