Linking EM to Your 2D and 3D Documentation

An EM graph becomes useful only when its nodes are tied to the things they describe — drawings, photographs, photogrammetric models, sections. This tutorial shows how to wire those connections so that, in Blender, every stratigraphic unit can be inspected spatially and the inverse — selecting an object on screen surfaces its graph entry.

It also explains the difference between document references (Document nodes, used for any source) and 3D documents (handled by the Document Manager), which add spatial-temporal placement.

Learning objectives

By the end you will be able to:

  • attach 2D drawings (sections, plans, orthophotos) to the units they document, with the right source metadata;

  • bind a 3D mesh — proxy or high-resolution — to a stratigraphic unit so that selection works in both directions (graph ↔ viewport);

  • place a 3D document in the scene (a camera + image plane) so that historic photographs sit in the same coordinate system as the reconstruction;

  • decide when to use a Document node, when to use a 3D document, and when to use both.

Prerequisites

  • Building an Extended Matrix Manually, Unit by Unit — the small graph you authored there is the starting point of this tutorial.

  • A scene with at least one mesh (proxy or photogrammetric) loaded into Blender.

  • One section drawing in PNG/SVG and one historic photograph (any format Blender can import as image plane).

Dataset

We extend the Casa di Esempio / Trench A example: section drawing of the east face, an orthophoto of the floor, two historic photographs, and a small photogrammetric mesh of one wall.

Todo

Companion files in preparation. Use your own equivalent dataset in the meantime — the structure of the steps does not change.

The walk-through

Step 1 — Document references for the 2D drawings

Data

Panel

Action

Output

section drawing PNG; metadata

yEd

Add a Document node, fill id, title, year, file_path (relative to DosCo); link to the units it documents.

The section is now reachable from every unit it shows.

Step 2 — Bind proxies to units

Data

Panel

Action

Output

the mesh; the active US

Proxy Box Creator

7-point pick on the mesh, name = US human ID.

Proxy aligned to the mesh, named to match the graph node.

all proxies

EM Data Tree

Reload.

Selecting the proxy highlights the US in the Stratigraphy Manager and vice versa.

Step 3 — 3D documents (camera + image plane)

For documents that have a position in space and time — historic photographs, archival drawings with a known viewpoint — use the Document Manager.

Data

Panel

Action

Output

photograph + capture date + estimated viewpoint

Document Manager

Create a 3D document; align the camera; set image plane.

The photograph appears in the scene from the right angle and is bound to its temporal anchor.

Step 4 — Cross-walk: from graph to viewport and back

Data

Panel

Action

Output

any unit selected in the graph

Stratigraphy Manager

Click the focus button on the row.

Camera flies to the proxy; related sources highlight.

any proxy selected in 3D

Paradata Manager

Enable Filter Paradata.

Properties / extractors / documents filter to the selected unit.

Self-check

  1. Selecting any of the eight units from Step 1 of Building an Extended Matrix Manually, Unit by Unit reveals the linked drawings or the 3D document, as appropriate.

  2. Two-way selection (graph ↔ viewport) works on every unit that has a proxy.

  3. The historic photograph appears in the scene at its correct location, oriented as it was taken.

Common pitfalls

  • file_path on Document nodes is relative to DosCo, not absolute. Absolute paths break as soon as the project moves machines.

  • A proxy that does not exactly match the US human ID will not link automatically — name them identically (case-sensitive).

  • 3D documents need a date or epoch reference, otherwise they cannot participate in epoch filtering.

Where to go next