Wave Overhang Settings Reference

This document describes every config option added by the wave-overhangs fork of OrcaSlicer, what it does, and how to tune it. For an overview of what wave overhangs are and why they exist, see the main README.

Contents

1. What wave overhangs are
2. How to enable
3. Tier 1 — Simple mode
4. Tier 2 — Advanced tuning
   • General
   • Geometry
   • Anchoring
   • Andersons-specific
   • Kaiser LaSO
   • Speed
   • Cooling
   • Floor layers
   • Support integration
   • Debug
5. Known limitations
6. G-code markers

What wave overhangs are

Wave overhangs let you print steep cantilevered overhangs without supports. Instead of dropping support columns from the bed, each ring of extrusion anchors to the one before it and the nozzle marches outward into empty space one fused-plastic rung at a time. Two algorithms are bundled: Andersons (outward-expanding wavefronts, based on Janis A. Andersons' research) and Kaiser LaSO (lateral seed-curve offsetting, based on Rieks Kaiser's master thesis).

How to enable

1. Open a model with an overhang.
2. Go to Print Settings → Wave overhangs.
3. Toggle Use wave overhangs (Experimental) on.
4. Pick an algorithm (Andersons or Kaiser).
5. Slice. Wave extrusions will appear in the G-code preview wherever overhangs are detected.

Simple mode only shows the 2 top-level controls (master toggle + algorithm). Switch the top-right mode selector to Advanced to see individual tunables.

Tier 1 — Simple mode

Two controls, always visible.

wave_overhangs

Master on/off switch. When off, none of the other wave-overhang settings have any effect and overhangs are printed with Orca's normal perimeter generator.

• Type: bool · Default: false

wave_overhang_algorithm

Which generator produces the wave pattern.

• Type: enum — andersons | kaiser · Default: andersons

No presets yet. The tunable space is large and the "right" bundles depend on printer, material, and geometry. Rather than ship opinionated defaults now, we want community test prints to surface what actually works — expect presets to return once there's real data.

Tier 2 — Advanced tuning

Every option below appears on the Wave overhangs page in Advanced mode, grouped by section.

General

wave_overhang_min_angle

Soft/metadata-only slope threshold. Currently not enforced — retained on the profile for future use.

• Type: float (°) · Default: 0 · Range: 0 – 90
• Why it's inert: the actual slope filter for what becomes an overhang is Orca's upstream Strength → Detect overhang walls + Overhang reverse threshold pipeline. By the time a region reaches the wave generator, it has already been classified as erOverhangPerimeter. A secondary local envelope check (earlier implementations) rejected every legitimate strip because the strip extends roughly one layer-height beyond the supported region by construction. If you want fewer or more overhangs flagged, adjust Orca's upstream thresholds instead.
• What to do today: leave it at 0. Use Overhang reverse threshold (Strength tab) to control which walls the slicer considers overhangs.

wave_overhang_min_length

Minimum perimeter length (mm) of a detected overhang below which wave generation is skipped.

• Type: float (mm) · Default: 0.0 · Range: 0 – 50
• Tuning: raise to 2–5 mm to avoid waving tiny overhang fragments (curved corners, small notches) where the travel/seam overhead isn't worth it.

Geometry

wave_overhang_outer_perimeters

Number of additional concentric outer perimeters drawn inside the overhang region before the wave fill.

• Type: int · Default: 1 · Range: 0 – unbounded
• Tuning: 1 is usually plenty. Raise to 2 for thicker outer shells on structural parts; drop to 0 for pure wave-only regions (experimental).

wave_overhang_pattern

Travel pattern between wave lines.

• Type: enum — monotonic | zigzag | smart · Default: smart

wave_overhang_perimeter_overlap

Extends the wave propagation boundary outward toward kept perimeter lines so the outermost wave sits closer to the shell.

• Type: float (mm) · Default: 0.1 · Range: 0 – unbounded
• Tuning: raise toward 0.2–0.3 if you see a visible gap between the last wave ring and the outer perimeter. Too high can cause wave lines to print into the perimeter.

wave_overhang_minimum_width

If a neck in the wave region is narrower than this width, insert a thin split there before propagation so fragile wave branches do not form (Andersons-only — the narrow-region handling from upstream alpha.6, switched to an absolute width in upstream master).

• Type: float (mm) · Default: 0.7 · Range: 0 – unbounded
• Tuning: raise to split more aggressively if wave rings skip over thin necks between lobes. Lower to 0 to disable splitting.

wave_overhang_line_spacing

Center-to-center distance between adjacent wave extrusions.

• Type: float (mm) · Default: 0.35 · Min: 0.01
• Tuning: tighter (0.28–0.30) = denser fill, stronger, slower, risk of over-extrusion on cantilevers. Wider (0.40–0.50) = faster, visible gaps between rings, weaker.

wave_overhang_line_width

Extrusion width for wave lines. Base extrusion volume is width × layer_height; the per-mm volume can then be scaled by wave_overhang_flow_ratio.

• Type: float (mm) · Default: 0.4 · Min: 0.1
• Tuning: typically match or slightly undercut the nozzle diameter. Narrower lines (0.35–0.38) cool faster and hold shape better on unsupported tips; wider lines are stronger but sag more.

wave_overhang_flow_ratio

Multiplier applied to the base extrusion flow for wave-overhang lines. Base cross-section is wave line width × layer height; the final per-mm volume is base × flow_ratio.

• Type: float (multiplier) · Default: 2.0 · Range: 0.1 – 3.0
• Why 2.0: Wave-overhang lines hang in air, not squished against a layer below, so the width × layer-height shape does not apply. Empirically they need roughly 2× the base flow to stay continuous — this matches Andersons' reference value of ~0.15 mm² for a 0.4 mm nozzle.
• Why a ratio (not an absolute mm²): keeps tuning portable across layer heights. A ratio of 2.0 tuned at 0.2 mm layer still makes sense at 0.3 mm layer — the effective cross-section scales with the geometry, instead of silently under-extruding when you change layer height.
• 1.0 reverts to Orca's base flow (width × layer-height). This typically under-extrudes wave lines because they aren't actually squished.
• Above 2.0 if wave lines still look thin / starved on cantilevered tips.
• Below 2.0 if wave lines blob or merge.

Tuning guide:

• Start at 2.0 and print.
• If wave lines look thin / starved / broken: raise to 2.2 – 2.5.
• If wave lines blob or merge: lower to 1.7 – 1.9.

wave_overhang_spacing_mode

How ring-to-ring step varies across the wave.

• Type: enum — uniform | progressive · Default: uniform
• uniform = constant step. progressive = tight at the supported root, widens toward the cantilever tip (better anchoring, slightly weaker tip).

wave_overhang_seam_mode

Direction pattern across successive rings.

• Type: enum — alternating | aligned | random · Default: alternating

wave_overhang_direction_bias

Kaiser-only. Rotates the wave-direction seed by this many degrees.

• Type: float (°) · Default: 0.0 · Range: -90 – 90
• 0 follows the natural root edge. Non-zero tilts the ring pattern — experimental, may push rings outside the overhang region.

Anchoring

wave_overhang_anchor_bite

Distance the wave extends into the supported region past the overhang root.

• Type: float (mm) · Default: 1.0 · Range: 0 – 5
• Tuning: raise (1.5–2.5) for tough filaments or cold beds where the first few rings are peeling. Lower (0.5) to minimize visible bite marks on the supported face.

wave_overhang_anchor_passes

Extra rings emitted starting from the supported edge before the main wave fan.

• Type: int · Default: 1 · Range: 0 – 5
• Tuning: 0 disables. 1 default. 2–5 for extreme >70° overhangs where the foot needs reinforcement. Each pass adds plastic and time.

Andersons-specific

These control the Andersons wavefront propagation. No effect when wave_overhang_algorithm = kaiser.

wave_overhang_wavefront_advance

Distance the wavefront advances per iteration.

• Type: float (mm) · Default: 0.7 · Range: 0.1 – 5
• Andersons' reference value: 0.7 mm.
• Tuning: smaller (0.4–0.5) = more rings, smoother surface, longer print. Larger (1.0+) = fewer rings, rougher, faster.

wave_overhang_discretization

Sample spacing along each wavefront when emitting the next ring.

• Type: float (mm) · Default: 0.35 · Range: 0.05 – 2.0
• Andersons' reference: 0.35 mm.
• Tuning: smaller = smoother arcs, heavier CPU. Larger = faster, can look polygonal.

wave_overhang_andersons_max_iterations

Safety cap on the number of wavefronts per overhang region.

• Type: int · Default: 0 (= unlimited) · Range: 0 – 500
• Propagation stops naturally when no new area is being gained; this is a hard cap for pathological cases.

wave_overhang_min_new_area

Terminate propagation when a new wavefront adds less than this much new area.

• Type: float (mm²) · Default: 0.01 · Range: 0 – 100
• Mode: Develop (not in Advanced page by default — expose via Develop mode).
• Andersons' reference: 1e-4 mm² (very small; our default is looser).
• Tuning: lower to keep propagating deep into tight regions; raise to terminate early on diminishing returns.

wave_overhang_arc_resolution

Arc-approximation segment count in Andersons wavefront geometry.

• Type: int · Default: 24 · Range: 4 – 128
• Mode: Develop.
• Andersons' reference: 24.
• Tuning: rarely needs touching. Raise for visibly faceted arcs at macro scale; lower to shrink G-code.

Kaiser LaSO

Only apply when wave_overhang_algorithm = kaiser.

wave_overhang_laso_overlap

Overlap fraction between successive Kaiser offset rings.

• Type: float · Default: 0.15 · Range: 0 – 0.9
• Tuning: raise (0.25–0.35) for denser, more solid coverage. Lower (0.05–0.10) for faster, more open pattern with visible gaps.

wave_overhang_kaiser_max_rings

Safety cap on ring count per region.

• Type: int · Default: 0 (= unlimited) · Range: 0 – 500
• Mirrors wave_overhang_andersons_max_iterations for the Kaiser side.

Speed

wave_overhang_print_speed

Print speed for wave extrusions.

• Type: float (mm/s) · Default: 2.0 · Min: 0.1
• Tuning: slower = better cooling and adhesion of cantilever rings. 1.5–2.5 mm/s is the usual useful range. Going above ~5 mm/s defeats the point of wave overhangs.

wave_overhang_travel_speed

Travel speed within wave regions between non-extruding hops.

• Type: float (mm/s) · Default: 40.0 · Min: 1.0
• Save-only in the current build — see Known limitations.

Cooling

wave_overhang_fan_speed

Part-cooling fan percentage forced during wave extrusions.

• Type: int (%) · Default: 100 · Range: 0 – 100
• Save-only in the current build — see Known limitations.
• Tuning: keep at 100 % for PLA/PETG. Drop to 40–60 % for ABS/ASA to reduce warping, but note cantilever rings benefit hugely from fast cooling.

Floor layers

wave_overhang_floor_layers

Number of solid floor layers placed directly above a wave region. Authoritative: this value overrides Orca's bottom_shell_layers behavior within the wave shadow — N means exactly N solid layers above the wave, not N-plus-whatever-bottom-shell-layers-adds.

• Type: int · Default: 2 · Range: 0 – 20
• N = 0 = zero solid layers above the wave footprint. The layer directly above the wave strip goes straight to sparse infill. Use for max material savings on purely aesthetic overhangs.
• N = 2 (default) = two solid-infill layers above the wave before sparse infill resumes. Standard mechanical backing.
• N = 3+ = heavier structural cap (slower, more filament, but stiffer).
• All N layers are stInternalSolid (regular solid infill) — no bridge classification is used, since these layers sit on top of the wave extrusions (which are solid material) rather than spanning air. Layer L+1 was previously misclassified as stBottomBridge and rendered as "Internal bridge" in the preview; that has been fixed so the whole floor window is uniform solid infill.
• Interaction with bottom_shell_layers: inside the wave shadow, the floor_layers value wins. Outside the wave shadow, Orca's normal shell rules still apply. Implementation: each affected layer gets a wave_overhang_shadow_polygons mask that is subtracted from the bottom-shell seed set in both discover_vertical_shells and discover_horizontal_shells, preventing further solid propagation above N.

Support integration

support_remaining_areas_after_wave_overhangs

When wave overhangs are on, generate supports only for overhang areas that weren't filled by wave toolpaths.

• Type: bool · Default: false
• Explicit support enforcers still apply normally.
• Tuning: turn on for conservative prints where wave coverage might miss edge cases — you get supports only where the wave algorithm gave up.

Debug

wave_overhang_debug_gcode

Emit ;WAVE_OVERHANG_START / ;WAVE_OVERHANG_END comments around wave extrusions and ;WAVE_OVERHANG_CONFIG banners at region boundaries.

• Type: bool · Default: true
• Comments only — no effect on the actual print. See G-code markers for format.

Known limitations

All user-facing options are now plumbed end-to-end. The table below notes mode exposure and any gotchas.

Andersons-reference-parameter tunables (wavefront_advance, discretization, anderson_max_iterations, min_new_area, arc_resolution) only apply when the Andersons algorithm is selected. Kaiser-only tunables (laso_overlap, kaiser_max_rings, direction_bias) only apply when Kaiser is selected.

Kaiser's original post-processor places discrete pin-support nubs under overhangs. Those are not ported and not planned — use support_remaining_areas_after_wave_overhangs with Orca's normal supports instead.

G-code markers

When wave_overhang_debug_gcode = true (the default), four kinds of comments appear in the output. They are pure comments — no motion, no effect on the print — but they're invaluable for verifying that waves were emitted and for bug reports (the full wave setup can be reconstructed from the header alone).

Build context (once, before any region banners):

; WAVE_OVERHANG_BUILD printer="<model>" printer_variant="<nozzle/variant>"
  filament_type=<PLA|PETG|...>
  layer_height=<mm> initial_layer_height=<mm>
  nozzle_diameter=<mm>
  nozzle_temp=<C> nozzle_temp_initial=<C>
  filament_flow_ratio=<ratio>

(Emitted as a single line — split here for readability.)

Region banner (once per wave region, before any extrusion):

; WAVE_OVERHANG_CONFIG region=<N> algo=<andersons|kaiser> outer_perim=<int>
  spacing=<mm> width=<mm> flow_ratio=<x> speed=<mm/s> travel=<mm/s> fan=<%>
  floor_layers=<int> min_angle=<deg> min_length=<mm>
  anchor_bite=<mm> anchor_passes=<int> direction_bias=<deg>
  laso_overlap=<frac> kaiser_max_rings=<int>
  pattern=<smart|monotonic|zigzag> spacing_mode=<uniform|progressive> seam_mode=<alternating|aligned|random>
  perimeter_overlap=<mm> minimum_wave_width=<mm>
  wavefront_advance=<mm> discretization=<mm>
  andersons_max_iter=<int> min_new_area=<mm²> arc_resolution=<int>
  support_remainder=<0|1>

(Emitted as a single line in the G-code; split across lines here only for readability.)

Extrusion block markers (wrap every wave extrusion):

; WAVE_OVERHANG_START
G1 X... Y... E...
...
; WAVE_OVERHANG_END

Verifying waves were emitted: slice your model, then grep the output for WAVE_OVERHANG_START. No matches means either Orca's upstream overhang-wall detection didn't flag any regions (check Strength → Detect overhang walls / Overhang reverse threshold), wave_overhangs is off, or your min_length threshold filtered everything. If you want the markers off for a production print, set wave_overhang_debug_gcode = false.