Revision Delta Report
Compare two model revisions and see exactly what changed — like a diff command for buildings.
Revision Delta Report
When the structural model changes — a beam section swapped, a column removed, a connection redesigned — FrameAI shows you exactly what changed, and whether it is still structurally valid. Think of it as a diff command for buildings.
Before you start
| Item | Details |
|---|---|
| Prerequisites | Model must have at least 2 saved revisions |
| Comparison | Any two revisions can be compared |
| Time | ~20–40 seconds for analysis |
Step 1 — Open the Revisions panel
In Studio, open your model. Click the **clock icon** in the toolbar to open the Revisions panel.
Step 2 — Select two versions
The Revisions panel shows all saved model versions in reverse chronological order. Select:
1. **The older version** (your baseline)
2. **The current version** (or any other comparison point)
Step 3 — Generate Delta Report
Click **Generate Delta Report**. FrameAI runs a structural diff between the two versions.
Analysis takes 20–40 seconds depending on model size.
Step 4 — Review the changes
The Delta Report shows:
- **Change summary at the top** — X added, Y removed, Z modified
- **Scrollable list of all changes** below
| Change type | Colour | Meaning |
|---|---|---|
| Added | Green | New member added to the model |
| Removed | Red | Member deleted from the model |
| Modified | Yellow | Member property changed (section, material, orientation, etc.) |
Step 5 — Jump to changed elements
Click any change in the list to jump to that element in the 3D viewer. The viewer pans and zooms to centre the selected member, with the change highlighted in context.
What you should see
A Delta Report page with:
- **Header summary** — e.g., "5 added, 2 removed, 12 modified"
- **Colour-coded change list** — scrollable, filterable by type (added/removed/modified)
- **3D viewer jump** — click any change to navigate to the element in context
Common problems
**Only one version available**Delta reports need at least 2 saved revisions. Keep working on your model — every manual save creates a new revision point. Auto-saves also count.
**Changes not detected**Minor cosmetic changes (e.g., text labels, annotation notes, colour overrides) are ignored by the delta engine. Only structural geometry changes, material changes, and section property changes trigger a delta entry.
**Delta report is empty**If both versions are structurally identical, the report is blank. Also check that both versions are the same structure type — comparing a steel portal frame to a concrete frame gives a blank delta.
**Large model causes timeout**For models with more than 10,000 members, delta reports process in background chunks. If you see a timeout message, check back in 2–3 minutes — the report will be ready in Studio.
What's next?
Night Shift — schedule overnight re-checks after model changes
Run Eurocode Calculations — verify that changed members still pass