A Catmull-Rom spline is a type of smooth curve that connects a series of points. It creates a flowing, natural-looking curve that actually passes through each control point in a polyline.
Category: Geometric Operations
Kind: Operation
Tags: Interpolate, Curve, Smooth
Description: Create an interpolated curve from a set of points
Inputs
Name | Abbreviation | Type | Access | Description |
Polyline | P | Cartesian | Item | The points to interpolate |
Smoothness | S | Number | Item | The smoothness of the curve |
Resolution | R | Number | Item | The resolution of the curve |
Periodic | P | Boolean | Item | Whether the curve is periodic |
Outputs
Name | Abbreviation | Type | Access | Description |
Polyline | P | Cartesian | Item | The interpolated curve |
How to
Input a polyline feature
Set the smoothness
Type a value in the box
Or input a number result from another node
Set the resolution
Type a value in the box
Or input a number result from another node
Example
Rendered curved line | Feature Selected |
 |
 |
Explanation
Resolution:
The number of segments (or sample points) calculated between each pair of control points
Higher resolution = more points along the curve = smoother appearance when rendered
Example: resolution of 10 means 10 line segments between each control point pair
This is purely a rendering/tessellation parameter - it doesn't change the mathematical curve itself
Smoothness (or Tension/Tightness):
Controls how tightly the curve follows the control points vs. how "loose" or "smooth" it is
Lower smoothness (tighter): Curve hugs the control points more closely, sharper turns
Higher smoothness (looser): Curve takes gentler, more gradual paths between points
This actually changes the shape of the curve itself
Practical tips:
Start with resolution around 10-20 for most uses; increase if you see visible angular edges
For smoothness, try values around 0.5 (if 0-1 scale) as a starting point
If your curve has unwanted loops or self-intersections, try reducing smoothness
If it looks too angular or doesn't flow naturally, increase smoothness