Use this when you want to create a smooth interpolated curve through a set of points within a flow, for example generating a road alignment or curved boundary that passes through defined vertices.
The Catmull-Rom node is only for adding specialized catmull-rom curves within a flow. Use the Corner Type property to change the corners of a basic geometry without flows.
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 polyline, points, or polygon to interpolate |
Smoothness | S | Number | Item | The smoothness of the curve (default 0.5) |
Resolution | R | Number | Item | The resolution of the curve (default 25) |
Outputs
Name | Abbreviation | Type | Access | Description |
Polyline | P | Cartesian | Item | The interpolated curve |
How to
Input a polyline geometry
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 the default resolution of 25; increase it if you see visible angular edges
For smoothness, start with the default of 0.5
If your curve has unwanted loops or self-intersections, try reducing smoothness
If it looks too angular or doesn't flow naturally, increase smoothness