[FEATURE] Diagonal Smoothing (Non-Planar Surface-Following Finishing Pass to Reduce Stair-Stepping) #1001

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MrUnknownDE · 2026-04-05T16:41:05+02:00

MrUnknownDE commented

2026-04-05 16:41:05 +02:00

Originally created by @SlimRG on 1/22/2026

Is there an existing issue for this feature request?

I have searched existing issues and discussions

On sloped outer surfaces and sloped “top” faces, planar layer stacking produces visible stair-stepping (Z “steps”). Adaptive/variable layer height helps, but it cannot fully eliminate the staircase effect on certain geometries without significantly increasing print time.

I’m requesting an optional “diagonal smoothing” mode that adds a surface-following finishing pass (non-planar toolpath with continuously varying Z) to reduce the stair-step appearance on selected surfaces.

Describe the solution you’d like.

Add an optional feature that, after normal slicing, detects candidate faces/surface regions likely to show stair-stepping (sloped faces relative to build Z) and generates an additional non-planar finishing pass that follows the surface (varying Z along the path) within safe constraints.

Proposed scope (minimum viable, to reduce risk/complexity):

Surface types:

Focus on external surfaces only (outer walls and/or top skins), not infill.

Optional: start with top surfaces only (or a user-selected modifier region) to limit collision risk.

Safety constraints:

User-set max slope angle (e.g., up to 10–20°) for non-planar moves.

User-set min clearance / collision envelope assumption (nozzle + heater block + fan duct) and/or “require high-clearance toolhead” warning.

Automatic fallback to planar moves when constraints are violated.

Quality controls:

Optional single-pass “smoothing skin” (similar intent to ironing but with Z variation).

Optional extrusion compensation (flow adjustment) for varying local geometry, or initially keep constant extrusion and document limitations.

UI/UX:

New checkbox: Diagonal smoothing (non-planar finish)

Preview visualization (distinct color) and warnings when disabled due to geometry/collision rules.

Per-object / per-modifier support (enable only where needed).

Why this is valuable (use cases).

Cosmetic parts where the sloped outer surface quality is the priority (decorative enclosures, airfoil-like parts, cosplay props, visible panels).

Ability to get near “sanded look” on slopes without forcing global tiny layer heights everywhere.

Acceptance criteria (what “done” looks like).

When enabled, OrcaSlicer generates a surface-following finishing pass that visibly reduces stair-stepping on eligible sloped surfaces.

The feature respects guardrails: max slope angle, clearance assumptions, and falls back to planar moves where unsafe.

G-code remains compatible with common firmware (Klipper/Marlin) that can execute coordinated XYZ+E moves.

Preview clearly shows where non-planar moves will occur.

Alternatives you’ve considered.

Adaptive/variable layer height (helps but doesn’t fully remove the stepped appearance and increases print time).

Post-processing (sanding/coating).

External post-processors / manual G-code “bending” approaches (works in limited cases, not integrated).

Additional context / notes.

This request is related to the broader “non-planar slicing” topic already discussed in the project; however, I’m proposing a narrower and potentially more implementable first step: a constrained surface-following finishing pass (“diagonal smoothing”) rather than full non-planar slicing for the entire print.

Environment

OrcaSlicer version: (fill in)

Printer/firmware: (e.g., Klipper)

Example model(s): (attach or link)

Photos: (attach showing stair-stepping)

*Originally created by @SlimRG on 1/22/2026* ### Is there an existing issue for this feature request? I have searched existing issues and discussions ### Is your feature request related to a problem? Please describe. On sloped outer surfaces and sloped “top” faces, planar layer stacking produces visible stair-stepping (Z “steps”). Adaptive/variable layer height helps, but it cannot fully eliminate the staircase effect on certain geometries without significantly increasing print time. I’m requesting an optional “diagonal smoothing” mode that adds a surface-following finishing pass (non-planar toolpath with continuously varying Z) to reduce the stair-step appearance on selected surfaces. ### Describe the solution you’d like. Add an optional feature that, after normal slicing, detects candidate faces/surface regions likely to show stair-stepping (sloped faces relative to build Z) and generates an additional non-planar finishing pass that follows the surface (varying Z along the path) within safe constraints. Proposed scope (minimum viable, to reduce risk/complexity): Surface types: Focus on external surfaces only (outer walls and/or top skins), not infill. Optional: start with top surfaces only (or a user-selected modifier region) to limit collision risk. Safety constraints: User-set max slope angle (e.g., up to 10–20°) for non-planar moves. User-set min clearance / collision envelope assumption (nozzle + heater block + fan duct) and/or “require high-clearance toolhead” warning. Automatic fallback to planar moves when constraints are violated. Quality controls: Optional single-pass “smoothing skin” (similar intent to ironing but with Z variation). Optional extrusion compensation (flow adjustment) for varying local geometry, or initially keep constant extrusion and document limitations. UI/UX: New checkbox: Diagonal smoothing (non-planar finish) Preview visualization (distinct color) and warnings when disabled due to geometry/collision rules. Per-object / per-modifier support (enable only where needed). ### Why this is valuable (use cases). Cosmetic parts where the sloped outer surface quality is the priority (decorative enclosures, airfoil-like parts, cosplay props, visible panels). Ability to get near “sanded look” on slopes without forcing global tiny layer heights everywhere. ### Acceptance criteria (what “done” looks like). When enabled, OrcaSlicer generates a surface-following finishing pass that visibly reduces stair-stepping on eligible sloped surfaces. The feature respects guardrails: max slope angle, clearance assumptions, and falls back to planar moves where unsafe. G-code remains compatible with common firmware (Klipper/Marlin) that can execute coordinated XYZ+E moves. Preview clearly shows where non-planar moves will occur. ### Alternatives you’ve considered. Adaptive/variable layer height (helps but doesn’t fully remove the stepped appearance and increases print time). Post-processing (sanding/coating). External post-processors / manual G-code “bending” approaches (works in limited cases, not integrated). ### Additional context / notes. This request is related to the broader “non-planar slicing” topic already discussed in the project; however, I’m proposing a narrower and potentially more implementable first step: a constrained surface-following finishing pass (“diagonal smoothing”) rather than full non-planar slicing for the entire print. ### Environment OrcaSlicer version: (fill in) Printer/firmware: (e.g., Klipper) Example model(s): (attach or link) Photos: (attach showing stair-stepping)

MrUnknownDE closed this issue

2026-04-05 16:41:05 +02:00

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Reference: github/OrcaSlicer#1001