[mahach666]

What changes and why

• New IfcIO.Scene project and package. IfcSceneReader.Read(path | IfcModel, IfcSceneOptions) converts an IFC model into an IOScene SceneDocument in metres with Z up, so viewers and coordination tools read IFC through the shared scene contract. It is ported from the IOViewer IFC adapter and uses only the public IfcIO API; the IfcIO package gains no dependency.
• Mapping: one SceneModel per file (Key = ModelKey, else the file name); SourceId and IfcGuid = GlobalId; storeys become levels and tree nodes; property and quantity sets are keyed ifc:<Set> / ifc:<Set>.<Name>; surface style colours become materials; work schedules become scene schedules. Elements without geometry and invalid meshes are reported as diagnostics. An empty ModelKey throws ArgumentException in both overloads.
• Dimensioned quantities are written as text: a scene Number with a null Unit means dimensionless, and the adapter converts no quantity to SI, so length, area, volume and weight quantities are Kind = Text in file units. Counts stay numbers with a null unit; property values are text.
• Golden identity test: placement.identity.txt freezes the model key, SourceId, IfcGuid, the ifc: key format and the value form (Text, Kind, Unit) of each key. Changing any of them is a breaking release (CONTRIBUTING, scene adapter page).
• Exact engine pin: IfcIO.Scene ships on the IfcIO tag and depends on exactly the same IfcIO version ([X.Y.Z], PinProjectReferencesExactly target). IOScene is referenced as [0.1.0-preview.2, 0.2.0-0), with NU5104 suppressed for that range.
• tools/pack-release.ps1 reads the packed IfcIO.Scene nuspec and fails the release when (a) the IfcIO dependency is not exactly [version], which guards the target hooked into a private NuGet target, or (b) the IOScene lower bound is a prerelease, which replaces the NU5104 protection.
• release.yml: release notes are extracted before anything is published, the NuGet push runs before the GitHub release so a refused first publication of a new package id can be fixed and the job rerun, and a tag with a hyphen creates a prerelease.
• Docs: new docs/scene-adapter.md (usage, mapping, value rule, coordinates, limits); docfx metadata and the docs workflow cover src/IfcIO.Scene; README, CHANGELOG [Unreleased] and CONTRIBUTING updated.
• IfcModel.ParseSweptSolid documents all its parameters (CS1573).

Tests

Restored with IOScene 0.1.0-preview.2 from a local package folder; the version published on nuget.org has the same public API and method bodies.

• New tests/IfcIO.Scene.Tests (net8.0, net10.0): golden identity on placement.ifc (now with valid GlobalIds, a property set and a quantity set), world placement and unit scaling, storeys, skipped type objects, properties/quantities/GlobalIds of a saved model, shared property sets, hostile strings through SceneJson, material alpha, spaces, duplicate ids, invalid meshes, work schedules, the IFC4 IfcTriangulatedFaceSet limit, missing and empty ModelKey. Every converted fixture must pass Validate() with no entries.
• Read_ConfiguredIfcFile_ConvertsEveryElement runs only when IFCIO_SCENE_IFC_FILE names an IFC file; it allows Validate() warnings (a real file may carry a malformed GlobalId) and fails on any error.
• dotnet test IfcIO.slnx -c Release: IfcIO.Tests 149/149; IfcIO.Scene.Tests 19 passed, 1 skipped (the configured-file test) on each of net8.0 and net10.0.
• dotnet build IfcIO.slnx -c Release: 0 warnings, 0 errors.
• Real IFC files (not committed, up to about 10,000 elements) converted to scenes and opened in IOViewer: Validate() reported nothing.
• tools/pack-release.ps1 under Windows PowerShell 5.1: it built all artifacts and packages, assertion (a) passed, and it stopped at assertion (b) as intended while IOScene is a preview. The assertion was also run on edited copies of the nuspec: a bare IfcIO version fails, a stable IOScene lower bound passes. Not run under pwsh, which the release workflow uses.
• docfx build: not run.

Notes

• Depends on IOScene on NuGet.org: IOScene 0.1.0-preview.2 is published there, and CI and the docs build restore it and pass (re-run after its publication).
• Merge order: IOScene 0.1.0-preview.2 is on NuGet.org and CI is green, so nothing else has to come first. Builds on fix: place IFC geometry in world coordinates and export GLB in metres, +Y up #35 (merged), which places IFC geometry in world coordinates.
• Release order, same as RvtIO: after this merge every IfcIO release fails at the IOScene lower-bound assertion in pack-release.ps1, including one that would ship only the [Unreleased] fixes, until IOScene 0.1.0 is published and the range in Directory.Packages.props moves to [0.1.0, 0.2.0-0) (CONTRIBUTING and the scene adapter page quote the range too).
• The first IfcIO.Scene push is a new package id; the NuGet trusted publishing policy pattern IfcIO* covers it.
• Not fixed here: IfcIO's reader returns no mesh for IfcTriangulatedFaceSet (pinned by a test), and type property sets are not read yet. Both are listed under Limits on the scene adapter page.