True-shape nesting
True-shape nesting software, online and free
Nestpact is online true-shape nesting software. It packs the real outline of every part, not the rectangle around it, so concave shapes nest into each other and you get more parts from every sheet.
Most fast nesters approximate each part as its bounding box. That is fine for plates and panels, but an L-bracket, a C-channel or a jigsaw profile leaves a lot of trapped air inside that box. True-shape nesting closes that gap by fitting parts against each other's actual edges.
Upload a DXF (or an STL, OBJ, PLY or 3MF solid), pick the NFP preset, and Nestpact interlocks your parts in the browser. No install, no CAD licence.
- Nests true part outlines, holes and concavities included
- No-Fit-Polygon (NFP) engine for genuine part-against-part interlock
- Part-in-part nesting: small parts tuck inside the holes of larger ones
- Free-rotation search to find the tightest interlocking angle
- Never worse than bounding-box packing: it keeps the better of both
- DXF and G-code export for laser, plasma, waterjet and router
What 'true shape' actually means
A nesting algorithm answers one question over and over: can this part sit here without overlapping anything already placed? The cheap way to answer it is to compare bounding boxes, the upright rectangle around each part. It is fast, but it treats an L-bracket as a solid rectangle, so nothing can ever sit in the notch of the L.
True-shape nesting compares the actual polygon outlines instead. Two parts can share the same bounding box and still interlock perfectly, because the collision test looks at edges, not boxes. That is the whole difference between a loose layout and a tight one on irregular parts.
How Nestpact interlocks parts: the No-Fit Polygon
Nestpact's NFP preset is built on the No-Fit Polygon, the classic true-shape nesting primitive. For any two parts, the NFP is the set of positions where they touch but never overlap. Slide one part around the boundary of that region and it hugs the other part's edges without ever colliding.
Nestpact computes NFPs as Minkowski sums of the real outlines, then places each part at the point on the boundary that packs tightest. It also computes an inner-fit polygon against the sheet (and against holes), so parts settle into concave sheet edges and offcuts, not just the open middle.
Concave parts are exactly where bounding-box packing leaves the most air. NFP is what lets brackets, rings and channels lock together the way an experienced nester would place them by hand.
Part-in-part: nest inside the holes
True-shape geometry also unlocks part-in-part nesting. If a large part has an interior hole (a washer, a frame, a flange with a bore), Nestpact can drop smaller parts into that hole, and recursively into the holes of those parts. Every one of those placements is verified against the exact unsimplified outline, so nothing intrudes where the cutter cannot go.
When to use true-shape nesting
If your parts are mostly rectangular panels, the standard presets are faster and pack just as tight, so start there. The moment your DXF has hooks, slots, cutouts, curves or mixed concave profiles, switch to the NFP preset and let it interlock them.
Nestpact keeps the better of the two approaches automatically. The NFP preset runs both the true-shape nester and the raster strategies, then returns whichever packed more, so choosing it never costs you utilization on convex jobs.
| Part type | Bounding-box packing | True-shape (NFP) nesting |
|---|---|---|
| Rectangular panels | Excellent | Excellent |
| L / T / U / C profiles | Wastes the notch | Interlocks into the notch |
| Rings and frames | Solid box, no infill | Parts nest inside the hole |
| Curved / jigsaw parts | Loose | Edges hug together |
| Speed | Fastest | Slower, higher yield |
Recommended starting settings
A good starting point for a concave, irregular job. Loosen rotation to give the interlocking search room to work.
The true-shape nester. Premium tier; the deep preset also runs it as a candidate on concave jobs.
More angles let concave parts find their interlocking fit. Lock to 0°/180° only for grained stock.
Match your kerf. Tighter gaps reward true-shape packing the most.
Let small parts fill the holes of larger frames and rings.
Frequently asked questions
What is true-shape nesting?
True-shape nesting packs parts by their actual outline instead of the rectangle around them, so concave shapes like L-brackets and rings interlock. It gets more parts per sheet than bounding-box nesting on irregular geometry.
Is true-shape nesting free?
Nestpact is free to try in your browser with no install. The dedicated NFP interlocking preset is a premium feature. Every preset already uses true part shapes for collision, and the deep preset runs the NFP nester as a keep-best candidate on concave jobs.
Which parts benefit most?
Concave and irregular parts: L, T, U and C profiles, rings, frames, flanges, and curved or jigsaw-cut shapes. Anything that leaves empty space inside its bounding box gains the most. Rectangular panels already pack tightly with the standard presets.
What file formats can I nest?
Upload parts as DXF, or as 3D solids (STL, OBJ, PLY, 3MF) that Nestpact flattens to a 2D silhouette. Export the finished layout as DXF, or as G-code for laser, plasma, waterjet or router.