Path Stroke

Overview

A rasterizer that turns a path into a pixel line resembling hand-placed pixels. It draws along a Bézier path and, by default, produces a pixel-perfect 1px line with extra L-shaped pixels removed. This is the most basic exit from a PixPipeline path into pixel art.

• Version: 2
• Generator: yes (is_generator: true — eligible for automatic canvas-size binding)

Usage tips

• The basic chain is bezier_path → path_stroke → blend. Start with thickness 1 and pixel-perfect ON, then tune line character with pp_mode: Diagonal for more diagonal lines, Cardinal for more horizontal/vertical lines, or the default RemoveCorner when unsure.
• Turn fill_closed ON to fill a closed shape as well. Line and fill may use separate colors, completing the pixel-art outline + interior idiom in one node.
• Connect the color input to manage line color through a palette or variable.
• Taper: set End Thickness to 1+ and the width blends from Thickness at the start to that value at the end. 3 down to 1 gives the classic grass / fur / tail / flame stroke (0 keeps the stroke uniform).
• Match canvas dimensions with the path source such as bezier_path. Both use canvas binding by default, so they normally align automatically.

Common pitfalls

• The line character changes at thickness 2 or more: pixel_perfect works only at thickness 1. Thick strokes apply a circular brush to the same centerline; even widths use a half-pixel right/down bias so the cross-section matches the requested width.
• Fill has no effect: the path is open. Close it in the bezier_path editor; fill_closed applies only to closed subpaths.
• Nothing appears: an unconnected path intentionally outputs a transparent image. Check the path input.
• Every path appears when only part of a multi-path is needed: set sub_path_scope = Single and choose with sub_path_index.

Drawing algorithm

thickness = 1 (pixel-perfect mode)

1. Sample each segment with rasterize_bezier_segment() and convert it to pixel coordinates.
   • Skip endpoints on .5 boundaries to prevent protrusion from round().
2. Merge coordinates from every segment and remove duplicates at joins.
3. Restore corner pixels at joins: when a diagonal gap is detected at a .5,.5 anchor, insert a corner pixel to prevent missing corners on squares and similar shapes. Do not insert one at non-right-angle vertices such as triangles.
4. For a closed path, connect the end to the start with Bresenham.
5. Guarantee eight-direction connectivity with ensure_8connected().
6. If pixel_perfect is enabled, remove duplicate L-shapes with PP correction.
7. For a closed path, apply wraparound L-shape correction.
8. Draw the resulting pixel coordinates into the image.

thickness ≥ 2

Adaptively flatten the curve into an eight-connected centerline, then stamp a circular brush at each point. Even widths use a half-pixel right/down bias, so horizontal and vertical cross-sections match thickness. pixel_line outputs this source centerline for every thickness.

fill_closed = true

Scanline-fill closed subpaths beneath the stroke. At thickness=1, the PP-corrected coordinate sequence is used as the polygon.

Examples

Basic path drawing

[BezierPath] → path → [PathStroke] → output → [Preview]

Colored path

[ColorRGB] → color → [PathStroke] → output → [Blend] → [Preview]
                          ↑
                     [BezierPath]

Drawing only one path from a multipath

[MultiPath] → path → [PathStroke(sub_path_scope:Single, sub_path_index:1)] → [Preview]

Downstream processing of pixel coordinates

[BezierPath] → path → [PathStroke] → pixel_line → [PixelLineNode]

Using it as a Surface

[BezierPath] → path → [PathStroke] → surface → [Surface Light Preview]

With fill_closed on, the closed interior is treated as part of the same Surface as the line.

Notes

• pixel_perfect correction applies only when thickness = 1.
• pp_mode, pp_closed_cross, and pp_closed_side appear only at thickness 1.
• pixel_line is always the rasterized centerline before the thickness brush is applied.
• An unconnected path outputs an empty transparent image.
• An unconnected path also returns an empty image and empty Surface.
• Surface parameters are collapsed under "Surface" in the inspector.
• Because is_generator: true, the node participates in canvas-size binding.
• Corner-pixel restoration at .5,.5 anchors is handled automatically inside rasterize_subpath.
• sub_path_index appears only when sub_path_scope = Single.
• The upper limit of sub_path_index updates in the UI to match the number of input subpaths.

Related nodes

• bezier_path / multi_path_editor — create the source path
• path_fill — when only the fill is needed
• pixel_line — draw from an explicit pixel-coordinate sequence
• outline — add an outline afterward to a finished image