Opus55 ignored NestJobPart.Priority, so the shared contract test (lower number wins scarce stock) failed; lower-number priority now precedes its placement score. SheetEconomics is replaced by the host's NestJobCost so it optimizes exactly what the benchmark scores, and its footprint margin comes from NestTolerances.SafeClearanceMargin plus four Clipper grid units - the same 0.003 total as before, which keeps its contact points. Synthetic benchmark (5 jobs, salvage 0.5): all valid, cost unchanged at 5452.79, time 611 -> 456 ms. Co-Authored-By: Codex <noreply@openai.com> Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
OpenNest Engines
Independent nesting engine plugins for OpenNest.
Each engine is a standalone class library that OpenNest discovers at runtime via
NestingEngineRegistry.LoadPlugins() — drop the DLL into an Engines/ folder next to
the OpenNest app or OpenNest.Benchmark build output.
| Engine | Approach |
|---|---|
| Gpt6Astra | Contact-based placement |
| Opus55 | Frontier-advance no-fit-polygon packing |
| Qwen38FlashNext | Bottom-left greedy insertion over convex NFPs with an exact clearance gate |
Building
Engines compile against an OpenNest checkout, expected as a sibling clone:
src/
OpenNest/ git clone https://git.thecozycat.net/aj/OpenNest.git
OpenNest-Engines/ this repo
Use a different location with /p:OpenNestRoot=<path> (or the OpenNestRoot
environment variable).
./Build-Engines.ps1 # build all engines + deploy to the benchmark
./Build-Engines.ps1 -Engines Opus55 # just one
dotnet test OpenNest.Engine.Opus55/tests/OpenNest.Engine.Opus55.Tests.csproj
Each engine's README covers its algorithm and benchmark results.
Writing a new engine
./New-Engine.ps1 -Name Nova
This copies _Template/ to OpenNest.Engine.Nova/: an INestingEngine stub, a README
spelling out what counts as an independent engine, BENCH-RULES.md (how a model's run
works: workspace limits, git, the real-part archive, reporting), and starter acceptance tests checked by
the benchmark's own NestValidator (they fail until Solve() is implemented).
To work inside an OpenNest checkout instead, stamp it into an Engines/ folder there and
bring the shared build files along; they detect that layout automatically:
./New-Engine.ps1 -Name Nova -Destination <OpenNest>/Engines -IncludeBuildFiles
Layout
Each engine lives in OpenNest.Engine.<Name>/ with an optional tests/ subproject.
Directory.Build.props supplies the target framework and the OpenNest.Engine
reference, so an engine's .csproj can be nearly empty.