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True-shape nesting

The 2D, 1D and Wood modes cut rectangles with a guillotine (edge-to-edge) saw. Many jobs are not rectangles: a steel bracket, a triangular gusset, a plastic gasket, a plywood profile with a cut-out. Packing those by their bounding box throws away the empty air inside each shape. Nesting mode packs parts by their real outline — arbitrary polygons interlock into each other’s concave pockets — so that air is reclaimed. It is the mode for laser, plasma and waterjet cutting.

It runs a different engine from the rectangular modes (a geometric collision engine, not the guillotine packer), so the 2D/1D/Wood plans are unchanged.

The honest metric for nesting is sheet count on the same parts, not a fill percentage. A rectangular packer counts each part’s bounding box as solid and reads a higher density for a worse result — on a representative 272-part job the true-shape nest used 6 sheets where the same parts by bounding box need 9.


Getting started

In 2D mode, switch to the Nesting sub-tab (next to Panel). Nesting is a sub-mode of 2D — the top bar has two tabs, 2D and 1D, and each reveals its own sub-tabs (2D → Panel / Nesting, 1D → Linear / Wood).

  1. 1

    Add your parts

    Click Import SVG/DXF and pick your outline files, or click Demo to load a sample job. Each imported outline becomes a part; a file with several outlines adds several parts, and concentric outlines become holes. You don't need a CAD file for simple shapes — add a rectangle, circle, ellipse, triangle, regular polygon, L-shape, or a fully custom polygon (enter its x,y points), or paste a list of rectangles from Excel / import a CSV (name, width, height, qty), just like the 2D panel-cutting table. On each stock sheet you can add one or more exclusion zones (a region kept clear of parts — a defect, knot or clamp footprint) with an editable X/Y/W/H.

  2. 2

    Add stock sheets

    Add one or more sheet sizes (name, width × height × quantity) — type them or paste from Excel. On any sheet you can add an Exclusion zone — a region the engine keeps every part off, for a defect, a knot or a clamp area.

  3. 3

    Set the options

    Give each part a rotation rule (Free, 90°, or None) and, if needed, a minimum separation for the kerf or beam width. Then press Run.

  4. 4

    Read and export the nest

    The results read like the 2D panel-cutting results: a yield/density summary, a 'how it was optimized' box, one diagram per sheet, a placement list and a material-requirements table. Use Downloads for SVG, DXF, PDF, Excel or CSV. Signed in, you can Save the nest as a project like any other cut.


Parts are polygons, not rectangles

A nesting part is an outline: a closed polygon of [x, y] points, optionally with interior holes. That is why parts have no width/height fields — the shape is the part. The importer builds these outlines for you:

FeatureTypeDescription
DXFfileLWPOLYLINE and POLYLINE outlines (arcs from bulges), plus LINE / ARC / CIRCLE / ELLIPSE segments chained into closed loops. The drawing's $INSUNITS is read for the unit.
SVGfilepath (with béziers and elliptical arcs flattened), polygon, polyline, rect, circle and ellipse. Concentric outlines become holes.
DemobuttonLoads a sample job — four brackets and four gussets on one sheet with a corner exclusion zone — so you can see the whole flow without a file.

Curves (arcs, béziers) are flattened to line segments at a fixed tolerance, so the same file always imports to the same part — a nest of imported outlines is reproducible.


Exclusion zones

A real sheet is not always perfect. On any stock row, Exclusion zone marks a region the engine treats as a no-go area — every part is kept clear of it. Use it for a board defect, a knot, a clamp footprint, or a pre-printed area. The zones are drawn on the layout so you can see what the nest worked around. This is a capability the rectangular modes have no way to express.


The result

The viewer shows each sheet with every placed part in its own colour, and the summary reports:

  • Sheets — how many stock sheets the nest used.
  • Density — the placed polygon area over the used sheet area. This is the honest fill; the concave pockets inside irregular parts count as empty.
  • Placed — how many part copies were placed out of the total requested. Anything that did not fit is listed.

Do not read density as a 2D-panel yield. They are not comparable — a bounding-box packer counts the notch-air inside a shape as used, so its “yield” reads higher for a worse layout. To compare two nesting results, compare sheet count on the same parts.


Exports

Nesting mode exports the achieved layout in the formats a workshop and a CAM tool need. All are under Downloads:

  • SVG — a self-contained drawing of the nest (one titled band per sheet, parts as filled polygons, exclusion zones hatched).
  • DXF — an R12 drawing with the outlines on STOCK / PARTS / HOLES / ZONES layers, ready for a laser/plasma/waterjet CAM tool.
  • PDF — a printable report: the layout drawn to scale per sheet, plus a placement list (part, sheet, x, y, rotation, material).
  • Excel — a workbook with an Overview sheet (sheets, density, placed) and a Placement sheet.

The layout is deterministic: the same parts and sheets always produce the same nest, so a quote or a cut program built from a nest can be reproduced exactly for a repeat order.


For developers

The same true-shape engine is available over HTTP on the Engine API at POST /v1/optimize/nest, so an ERP, a CAD/CAM tool or a quoting system can nest without a browser. See the Engine API reference for the request and response shape.

FAQ

What is true-shape nesting?
It packs parts by their real outline, not by a width×height rectangle. Irregular parts — an L-bracket, a triangular gusset, a gasket with holes — interlock into each other's concave pockets, so the empty air a rectangular packer wastes is reclaimed. It is the mode for laser, plasma and waterjet cutting, and it is a different class of algorithm from the guillotine (edge-to-edge) packer the 2D, 1D and Wood modes use.
How do I get my part outlines into the app?
In 2D mode, open the Nesting sub-tab (next to Panel) and click Import SVG/DXF. The app reads closed outlines from a DXF (LWPOLYLINE, POLYLINE, LINE/ARC/CIRCLE, with arcs flattened) or an SVG (paths, polygons, rectangles, circles), turns concentric rings into holes, and adds each one as a part. You can also click Demo to load a sample job and see the whole flow.
Can I nest around a defect or a clamp area?
Yes. On any stock sheet, click Exclusion zone to mark a region the engine keeps every part off — a board defect, a knot, a clamp footprint or a pre-printed area. This is something the rectangular modes cannot express.
Why does the density look lower than a 2D panel yield?
Density is the placed polygon area over the used sheet area — the honest fill, with the concave pockets inside irregular parts counted as empty, because they are. It is NOT comparable to a rectangular packer's yield, which counts each part's bounding box (notch-air included) as solid and so reads higher for a worse result. The metric to compare on is sheet count on the same parts.
What exports does Nesting mode produce?
SVG and DXF of the achieved layout (ready for a CAM tool), a printable PDF with the layout and a placement list, and an Excel workbook with an Overview sheet and a Placement sheet (part, sheet, x, y, rotation, material). Use Downloads for SVG/DXF/PDF/Excel.
Is the nest reproducible?
Yes. The layout is deterministic — the same parts and sheets always produce the same nest, so a quote built from it can be reproduced for a repeat order or an audit.
Is Nesting mode free?
True-shape nesting is a Pro-class feature. Signed-in users have it; a guest is prompted to sign in first. Like every mode, a run counts against your monthly optimization allowance (the Free tier includes 3 per month).

Last updated: August 31, 2026