The Interlock preset exists to nest concave shapes (L, T, U, notched panels) so they lock into one another. But on many real jobs, choosing a finer rotation step (Free at 5 degrees, 15, or 30) produced the same blocky, axis aligned layout as 90 degrees. The parts wanted to tilt into each other and the engine was leaving that on the table.
When the Interlock preset settles on a mostly axis aligned layout and some parts are still unplaced, it now hands that layout to the global rotation optimizer, which tilts parts to fine angles and searches for the interlocked arrangement a single left to right pass cannot find.
What changes for you
- More parts fit. On the customer job that motivated this change the engine went from placing 13 of 14 parts to all 14. Where a fine rotation step can rescue a part that would otherwise be left over, it now does.
- Interlock is faster. A budget bug let one consolidation step run several times past its limit on fine rotation steps. Fixing it cut a real customer job from over seven minutes to under three, with an identical layout.
- Never worse. The rotated layout is adopted only when it places at least as many parts in a smaller footprint (or fits more area). If tilting does not help, you keep the original layout, so quality can never regress.
The refinement runs only on the Interlock preset, only when you have chosen a fine rotation step, and only when the parts are concave enough to benefit. Convex and rectangular jobs, where axis rows are already optimal, are untouched and stay fast.
Note that on a sheet where every part already fits, a finer rotation step will usually produce the same layout as 90 degrees. Consolidating an already complete nest into a larger reusable offcut is a different problem, and one we are still working on.