RubberfitREV · 2026.05
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01 · The cutting engine

Rust-powered nesting that actually packs.

Two modes for two kinds of cuts. Auto Nest runs a Rust pipeline with sparrow-style Guided Local Search to optimize roll yield in seconds. Free-roam gives operators a manual canvas when the spec demands it.

A · Auto Nest · live demo

Press Pack. Watch material land flat.

The real engine packs in under three seconds for typical sheet sizes. The animation below cycles every seven seconds — same parts, same logic, same Rust code path.

SHEET 01 · 96 × 56 in · 60A
PACKING
P-001220×140P-002180×140P-003272×90P-004130×130P-005134×130P-006200×110P-007200×110P-008320×122P-009220×122P-010132×152
B · Engine internals

Real algorithms. Not chatbots.

The packing pipeline is a real Rust workspace — four crates, full Cargo test coverage, and a CLI binary the Next.js app shells out to via stdin/stdout JSON.

01

Polygon bin packing — jagua-rs

The geometry layer is jagua-rs, a research-grade polygon nesting library. It handles non-rectangular parts, rotation, and concave shapes — not just rectangles.

Crate · rf-geometry
Geometry · Convex + concave + rotation
02

Guided Local Search — sparrow

A sparrow-style GLS metaheuristic explores the placement space, escaping local optima the greedy heuristic can't. The result is yields that beat hand-planning by double digits.

Crate · rf-layout
Method · Sparrow GLS
03

Pack-CLI

A standalone Rust binary that takes a JSON pack request on stdin and writes the layout on stdout. Same binary runs locally, in CI, in the production server, and in a future native desktop build.

Crate · pack-cli
Binary · rubberfit-pack
04

Audit-grade layout JSON

Every Auto Nest run records its full layout JSON to cut_history. The exact placement of every part, the yield percent, the operator, and the timestamp — replayable forever.

Storage · cut_history.layout_json
Replay · Lossless
C · Free-roam mode

When the cut needs a human eye.

Some cuts don't optimize cleanly — a defect on the roll, a customer-specific orientation, a rush job. Free-roam gives the operator a live canvas with snap, rotate, and overlap detection while preserving the same audit trail Auto Nest produces.

Snap precision
0.5mm
Sub-millimeter snap on grid lines, sheet edges, and existing parts.
Rotation
Free°
Continuous rotation with optional 15°/45°/90° snap.
Overlap detection
Live
Polygon-aware collision detection. The cut tool refuses overlapping placements.
Audit log
Same
Manual cuts share the same cut_history record format as Auto Nest.
D · What it costs

Fast enough that operators wait on you, not the engine.

The engine is benchmarked against typical sheet sizes (4–9 sqm) with 8–24 parts. These numbers are measured on a single c5.large equivalent.

Median pack time
1.8s
8 parts, 6 sqm sheet, 95th percentile under 4s.
Yield improvement
+18%
vs. hand-planned cuts on the same job spec.
Concurrent operators
Unlimited
Each pack request runs in its own process.
Cold start
~50ms
Rust binary, no JIT warmup.
Ready when you are

See the price. Start a trial.

Per-seat pricing. 14-day free trial, no credit card. Run real cuts against your own stock — if it doesn't pay for itself the first week, walk.

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