Nesting Components

Nest Parts (Nest)#

Nests flat parts onto stock sheets with minimal waste. Parts pack against their true outlines (concave shapes interlock), keep a gap between each other, and rotate in fixed steps. Parts of different material or thickness go onto separate sheets. When parts don't fit on one sheet, more sheets are opened. Parts that fit on no sheet are listed on Unplaced.

Nesting decides where each part sits on which sheet. You give it flat parts and the stock you have; it returns a transform per part that you can use to move the real geometry.

Parts pack against their true outlines, not their bounding boxes, so an L-shape nests into the notch of another L-shape. Two spacings control the packing: the Gap between neighbouring outlines, and the Margin inset from the sheet edge. Leave Gap unset and it is derived from the material thickness.

Parts of different material or thickness never share a sheet. They are split into groups and nested separately, so a 2 mm part can never land on a 3 mm sheet.

Inputs#

Outputs#

Tracking parts through the nest#

The nester rearranges your parts, but the outputs come back on the paths you sent in. A part at {0;3} comes back at {0;3;0}, with one extra level for the copy.

So a tree of parts in gives the same tree out. No lookup, no index to match up: whatever you fed into branch {2;7} comes back under {2;7}.

Parts in          Outlines out
  {0;0}      ->     {0;0;0}
  {0;1}      ->     {0;1;0}
  ...               ...
  {2;8}      ->     {2;8;0}

The extra level is the copy number. Ask for one of each and every branch ends in ;0; ask for three of the part at {0;3} and you get {0;3;0}, {0;3;1}, {0;3;2}.

#### Which sheet did it land on

On Sheet (OS) is the map. It sits on the same paths as everything else and gives the index of the sheet each copy went onto, matching the branch order of Sheet Frames.

To pull out everything on sheet 2, cull by that value rather than by path. To count parts per sheet, group by it.

Sheet number is deliberately *not* a path level. Keying the output by sheet would produce paths like {2;7} that look exactly like your input tree but mean something completely different, and wiring the two together would silently pair up the wrong parts.

#### Moving more than the outlines

Outlines (O) only gives you curves. When you have something else that belongs on the part, a marking line you drew on the flat pattern, drill points, the 3D solid, use Transform (X):

[your line on the flat] ──┐
                          ├─→ (Transform) ─→ it lands on the nested part
[Nest] Transform (X) ─────┘

Because Transform comes back on your own paths, a line you made for the part at {0;3} matches the transform at {0;3;0} directly.

For Orient, transform a World XY plane by it: the plane and the transform describe the same move.

Mixed thicknesses on one job#

Parts of different thickness are never nested onto the same sheet. They are split into groups by material and thickness, and each group gets its own sheets.

For that to be counted correctly, the nester has to know what thickness each stock sheet carries. Set Thickness on each Sheet Stock:

[Sheet Stock]  2500x1250  t=2  Q=10   ─┐
                                      ├─→ Stock ─→ [Nest Parts]
[Sheet Stock]  2000x1000  t=3  Q=4    ─┘

Leave Thickness at 0 and that sheet serves any thickness. That is what you want for a single-thickness job, but on a mixed job all thicknesses draw from the same 10 sheets, so the thickness nested first can use them all up. The nester warns when it spots that combination.

Thickness comes from the parts automatically when they arrive as Unroll Results, so you normally only set it on the stock side. Closed curves carry no thickness, so they only go onto stock with Thickness 0.

Material works the same way. Set it on the part with Sheet Properties and on the stock with Material, spelled the same on both (capitals do not matter). Stock with no Material serves any part. A part with no Material only goes onto such stock.

To see which sheet is which, read the label under each sheet in the viewport, or take the per-sheet lines from Info (I).

Remnants: using up your offcuts#

A remnant is scrap you already have, rather than fresh stock you would buy. Mark a sheet size as a remnant and it gets used before any standard stock, so odd offcuts leave the rack instead of sitting there.

This matters most when an offcut is *larger* than a standard sheet. Without the remnant flag, the nester opens the smaller standard sheet first and your big offcut never gets touched.

Set Remnant on the Sheet Stock for that sheet. It travels with the sheet, so it cannot end up describing a different size.

A worked stock list#

Say you buy 2500 × 1250 sheets, and you have two offcuts left from an earlier job.

0 means unlimited, which is what you want for stock you can reorder. The offcuts are capped at 1 because you only own one of each. The nester fills both offcuts first, then opens as many 2500 × 1250 sheets as the job needs.

Quick mode and deep optimize#

By default the nester runs a single greedy pass and returns immediately. Switch Optimize on and it searches part order and rotations with a genetic algorithm until the Time Budget runs out, which usually buys a noticeably better yield.

The budget is spent *per material and thickness group*, not for the whole job. Four different materials at a 10 second budget is up to 40 seconds of solving. With Separate Parts on, it is spent once per part. Yield climbs steeply at first and then flattens, so raising the budget far past the default rarely pays for itself.

Reading the Unplaced output#

Unplaced (U) is empty when everything fits. Any entry means a part never made it onto a sheet, with the reason:

• No stock with this material and thickness. No Sheet Stock matches the part. Check Material and Thickness on both sides.
• Larger than every matching sheet. Check that Gap and Margin have not eaten the clearance a just-barely-fitting part needed.
• Stock exhausted. The part fits, but every matching sheet hit its Quantity. Raise a Quantity, or set one to 0 for unlimited.

Tips#

• Rotation Steps: more steps can raise yield. 8 (45° steps) is the default, 4 gives 90° steps, and 1 disables rotation.
• Respect Grain lines up each Unroll Result's grain with the stock's X axis, turning it only 0° or 180°. The grain runs across the bend lines, unless you set it with Grain on Sheet Properties.
• Allow Flip lets the nester mirror parts. It is off by default, because a mirrored part is cut face down. Parts with a different finish on each side (set on Sheet Properties) are never mirrored.
• Min Hole Area speeds up parts with many small holes. Holes below it are left out of the area used for sorting and yield, but they are still cut. Parts are never placed inside holes.
• Separate Parts keeps each part type on its own sheets. Sorting at the machine gets much easier, at the cost of yield.
• The Result (Res) output carries the full nesting result in true sheet-local coordinates, which is what you want for CNC and machine-file tooling. The Outlines and Sheet Frames outputs are laid out side by side for preview only.

Sheet Stock (Stock)#

Describes one sheet you can cut from: its size, how thick it is, how many you have, and whether it is an offcut. Feed several into Nest Parts to describe a whole rack.

Inputs#

Outputs#