Shape-preserving Path Smooth

Overview

Reduces small back-and-forth irregularities in hand-drawn paths, traced image/Region outlines, and generated lines. It preserves subpath count, closure, roles, holes, and A30 curves. If smoothing would cause a dangerous self-intersection or hole escape, only that shape is restored. This is finishing cleanup, not a general reshaping tool.

Usage tips

• A common chain is trace or multi_path_editor → path_smooth → path_stroke / path_fill. Start with strength 0.3–0.5, 1–2 neighbors, 1–2 iterations, and 0.5–1px maximum movement.
• For a rough automatic trace, try up to 2px movement, but increase strength, neighbors, iterations, and movement one at a time.
• Use about 100° corner protection for buildings and machinery, about 45° to preserve only sharp leaf or lightning tips, or 0° when corners should round.
• Keep Lock Open Endpoints enabled for cables or lines that meet other parts. Disabling it can pull endpoints inward and shorten the whole path.
• Closed paths are processed cyclically without depending on the starting anchor. Hole containment is checked, and unsafe parent/hole candidates are restored with a warning.
• Maximum Movement is the total displacement from the input position, not a per-iteration limit.

Common mistakes

• Almost nothing changes: lower corner protection from 100° to 60° to 0°, then raise Maximum Movement slightly.
• The result is too round: reduce neighbors or iterations, return movement to 0.5–1px, and raise corner protection toward 100° for right angles.
• A warning appears and the original shape remains: fix upstream self-intersections, collapsed/reversed area, holes leaving their parent, or discontinuous segments.
• Point count does not decrease: this node safely smooths shape and metadata; it does not simplify path data.

Related nodes

• path_connect — join split paths before smoothing
• path_extend — extend only an endpoint after smoothing
• path_deform — intentionally add waves, bulges, or squash instead of removing noise
• path_stroke — inspect the smoothed result as a line
• path_fill — inspect closed-outline and hole preservation