The cut plan

The saw sequence behind a 2D layout.

cutPlan — what one step means physically

A step is one blade movement, and the list is in the order you can actually saw: a parent cut before the cuts inside the piece it produced, because you cannot crosscut a strip before you have ripped it off. axis "h" means the blade travels along x and separates top from bottom; axis "v" means it travels along y and separates left from right. pos is the blade’s LOW-COORDINATE edge — the y value for "h", the x value for "v" — not its centre line: the kerf occupies pos to pos + kerf, so the blade eats in the direction the coordinate grows, which is downward for "h" and to the right for "v".

The material on the low side of the line — above it for "h", to its left for "v" — is the piece that cut frees. length is how far the blade travels on that one cut: the extent of the region it crosses, not the width of the whole board.

stage is a machine pass. It starts at 1 and increments only when the axis flips relative to the parent cut, so ripping a board into six strips is one stage and crosscutting them is the next. That is the panel-saw sense of “three-stage cutting”, not the depth of the cut tree, and it is what maxCutStages constrains. sheet is a 0-based index into sheets, and step restarts at 1 on every sheet instead of running across the whole job.

cutPlan is null — not missing, not empty — whenever guillotineValid is false: a layout that cannot be cut edge to edge has no cut sequence to return. It is absent from the payload altogether if you left it out of include.