Extended Matrix is a formal language for documenting stratigraphic sequences and virtual reconstruction processes — designed to be readable by people, processable by machines.
Most virtual reconstructions look certain even when the evidence beneath them is fragmentary, contested, or simply missing. Extended Matrix lets archaeologists record what was found, how it was read, and where the reconstruction goes beyond the data — so colleagues, reviewers and the public can see the reasoning, not just the result.
From the stratigraphic sequence on site to the published 3D scene, every interpretive step stays linked to the source that justifies it.
The same EM data shows up in the photogrammetric model, in the stratigraphic graph, in the project's data tree, and in the public Heriverse scene — each view is a different reading of the same knowledge.
Below is a live Heriverse scene — the same EM data you saw above, published as an interactive 3D experience. Walk through the reconstruction, click on a unit, read the paradata that justifies each interpretive choice.
Like a musical score versus its MIDI encoding, Extended Matrix is the human-readable notation: it can live on paper, in yEd, or in an AI-extracted spreadsheet. The s3dgraphy Python library makes that notation computable — and the rest of the framework brings it into Blender, into the web, into VR.
The property graph already carries CIDOC-CRM mappings, making EM data interoperable with the broader cultural heritage ecosystem.
Pick your starting point →One graph, many surfaces. s3dgraphy ingests EM from any notation and serves it to any consumer.
A growing family of open-source tools built around the s3dgraphy knowledge graph — from field documentation to immersive web publication.
3D visualisation and interactive annotation of stratigraphic units directly inside Blender.
The graph engine: import, export, validate and query EM knowledge graphs.
Heritage Science Metaverse — paradata pop-ups, epoch switching, collaborative VR for EM-aware scenes.
Photogrammetry and 3D model preparation upstream of EM Tools, on modest hardware.
Recurring meetings calendar reopens after EM 1.5 LTS: EM Hour on the 11th (community happy hour) and Dev Meeting on the 23rd (public coordination). Both on Teams in the browser — no Microsoft account needed; please use your real name when joining.
EM 1.5 ships with Landscape mode, CronoFilter, the new TSU vocabulary, an LTS commitment, and a refreshed EM Tools manual — the result of two years of work and the launchpad for the StratiGraph 1.6 cycle.
EM is now a building block of the StratiGraph European project — funded by the European Commission and contributing to the European Collaborative Cloud for Cultural Heritage (ECCCH).
The EM Framework is split into focused components — yEd palette, s3dgraphy, EM Tools, 3DSC, Heriverse — each with its own repository, documentation and release cycle. You pick what you need. The shared graph format keeps every piece in sync.
Bringing EM into another platform — Revit, 3ds Max, Unity, Unreal,
a CLI batch job — is a pip install s3dgraphy away. The
data model is the same everywhere, including its CIDOC-CRM mapping.
Extended Matrix is part of the European research infrastructure for cultural heritage. It is committed to long-term standardisation, formal mapping to community ontologies, and integration with the emerging European Collaborative Cloud.
EM 1.6 ships an alignment to the ISO CIDOC-CRM ontology — stable from the StratiGraph release cycle — together with a dedicated EM extension to CIDOC-CRM for archaeology-specific concepts. EM 1.6 also aligns to the Heritage Digital Twin Ontology (HDTO) developed in ECHOES for the ECCCH ecosystem. Your data plugs into the broader cultural-heritage standards layer.
From version 1.4, the formal language follows a long-term support cycle: a stable release is maintained for years so research projects — which often span multiple years — can build on a fixed target without churn. Backward compatibility is structural to EM: at any point you can move forward to the latest version and gain new language features and tooling without losing your work.
Extended Matrix is being matured (2025–2029) within the StratiGraph project, funded under the European Collaborative Cloud for Cultural Heritage (ECCCH). StratiGraph hardens EM as shared infrastructure: governance, versioning, validation suite, CIDOC-CRM/HDTO mapping, reference triplestore export. The outcome reaches users through first-class EM Tools and Heriverse connectors to the federated ECCCH nodes.
Extended Matrix grows version after version. The 2015 foundation paper is always cited; each release additionally contributes a flag paper you cite when you used features it introduced. The How to cite EM page assembles the full list per version, with ready-made BibTeX, and links to the canonical References and Glossary pages of the language documentation.
How to cite EM →Reference datasets, training material and case-study GraphML can be deposited on the Extended Matrix Zenodo community — every deposit gets a DOI and is preserved for the long term. The first fully downloadable case study (the Great Temple of Sarmizegetusa) is being prepared, alongside a dedicated deposit protocol.
Coming soon: each released case study will be published as a versioned dataset on Zenodo and cited by an accompanying data paper in Heritage (MDPI), so the underlying evidence stays as citable as the reconstruction itself.
Browse the EM Zenodo community →EM is adopted, funded and co-developed by —
See the full list on the about page.
