# Ortho source-model mapping

## Confirmed Plant 3D 2026 read path

```text
Active Ortho document
→ OrthoProject.DwgSheetDefinitions
→ IDwgSheetDef.DwgViewDefs
→ IDwgViewDef.DwgQuery.ModelFiles[].ModelFileName
→ PipingProject.GetPnPDrawingFiles()
→ exact normalized-path match to PnPProjectDrawing
→ PnPProjectDrawing.Id
→ DataLinksManager.SelectAcPpRowIds(int dwgid)
→ GetObjectClassname / GetAllProperties
→ independent PlantObjectSnapshot
→ AnnotationPlanBuilder
```

`PlantOrthoViewportReader.ReadViewports` reads the typed DwgQuery contract and
creates an Ortho viewport snapshot. `PlantObjectReader.ReadObjects` resolves
the resulting model-file reference through the Piping project drawing list and
reads DataLinks by project drawing ID. The active Ortho database is not a
Piping-row source.

All calls are read-only. The adapter opens no write transaction and does not
save a drawing, DCF, or project metadata.

## Diagnostics

The source reader returns stable telemetry diagnostics rather than suppressing
the result of a failed query: `ORTHO_SOURCE_DRAWING_NOT_RESOLVED`,
`ORTHO_SOURCE_DRAWING_NOT_IN_PROJECT`, `ORTHO_SOURCE_DRAWING_AMBIGUOUS`,
`PIPING_PROJECT_PART_NOT_FOUND`, `SOURCE_DATALINKS_UNAVAILABLE`,
`SOURCE_DATALINKS_NO_ROWS`, `SOURCE_DATABASE_READ_FAILED`,
`SOURCE_PIPE_ROWS_NOT_FOUND`, or `SOURCE_DATALINKS_READ`.

Exact membership of a source object in a particular Ortho viewport is not yet
implemented. A source-level DryRun plan must not be presented as proof of
viewport membership.