This 2D companion strips the 3D cutting-table scene down to the exact algorithmic view a real Gerber or Lectra cutter's control software actually works from: a flat plan of the fabric roll, seen from directly above, so the packing logic and the toolpath are both fully legible instead of partly hidden behind perspective.
Nesting uses Next-Fit Decreasing Height (NFDH), a classic shelf bin-packing heuristic โ identical to the 3D version, computed with the same code:
1. sort pieces by height, tallest first
2. open a shelf of height = current piece's height
3. place pieces left-to-right on the shelf while they fit
4. when one doesn't fit, close the shelf and open a new one below it
utilization = ฮฃ(piece area) / (fabric width ร used length)
When rotation is allowed, any piece taller than it is wide is rotated 90ยฐ before sorting โ trading a tall, narrow footprint for a short, wide one usually shortens the shelves and raises utilization, exactly why real nesting software always tries both orientations.
The cutting head then visits every piece in shelf order. Between pieces it makes a fast rapid move (no cutting, ~3ร feed rate); along an outline it moves at the programmed feed rate you set with the slider, and only that time counts as "cutting time elapsed" โ the same G0/G1 distinction a real CNC program makes.
Drag the cutting bed to pan and scroll to zoom in on the packed layout โ useful for checking how tightly pieces sit against each other once you tighten the kerf spacing.