Quad Strip

A ribbon that flows along a control point curve.

Quad Strip is a ribbon flowing along a Catmull-Rom curve — roads, rivers, cables, ribbons, rails.

Geometry

Samples the control point polyline at Curve Segments per span and builds a ribbon by applying width, taper and twist to a horizontally stabilized frame.

Thickness 0 — a single-sided strip with no thickness (no top, bottom or sides)
Thickness above 0 — a solid with bottom, top, sides and end caps; the bottom follows the curve and the thickness rises from it.

An open curve passes exactly through its end control points, and Closed Loop joins the start and end into a closed ring (no caps).

Different Start / End Width Scale values taper the ribbon, and Twist rotates it progressively along the curve.

Parameters

Label	Script key	Default	Range	Description
Width	`w`	1	0.01 ~ 1000	Ribbon width in meters
Thickness	`th`	0	0 ~ 1000	Thickness in meters — 0 gives a single-sided strip
Twist	`ang`	0	-1080 ~ 1080	Total twist along the curve, in degrees
Start Width Scale	`r1`	1	0.01 ~ 100	Width multiplier at the start
End Width Scale	`r2`	1	0.01 ~ 100	Width multiplier at the end
Points	`cu`	4	2 ~ 32	Number of control points
Curve Segments	`depthsegs`	8	1 ~ 64	Curve divisions per control point span
Width Segments	`widthsegs`	1	1 ~ 32	Divisions across the width
Closed Loop	`closed`	off	on / off	When on, joins start and end into a closed loop

Control point positions are editable only in the editor. A script can set counts, divisions, width, thickness and twist. Changing the Points count reinitializes the control points to a straight line.

How to create

Drag a rectangle in empty space. The long side becomes the curve length and the short side the ribbon width, and the transform auto-rotates to follow the long side. Control points are laid out as a straight line of that length.
Click to confirm, then move the mouse up to set the Thickness — near zero it snaps to a thickness-free strip.
Click again to finish, then move the control points to shape the curve.

Scene view editing

Uses control point handles instead of size handles. The interaction is the same as NURBS Surface — CP dragging, the selection-center gizmo, range selection and Reset Points.

Width, thickness, twist and taper are set in the Inspector.

Tips

For roads and rivers, keep Thickness at 0, raise Width Segments to 2–4 and place the CPs to follow the terrain.

For cables and ribbons, a little Twist goes a long way — even 90° reads clearly.

When you need a closed ring, such as a spiral handrail, turn on Closed Loop — the caps disappear and the ends join smoothly.

If the curve looks faceted, raise Curve Segments before adding Points; adding CPs means reshaping the curve.

Script

In a script this shape is written as quadstrip.

quadstrip "Road" w=6 th=0 cu=6 depthsegs=16 widthsegs=3 @0,0,0
quadstrip "Ribbon" w=0.3 th=0.02 ang=180 r1=1 r2=0.4 cu=8 @10,0,0