Step 7: Measurements and Analysis¶
Purpose¶
This step turns the traced rib curves from Step 6 into a structured measurement dataset. It works in two linked sub-stages: first you organise and label the ribs, bosses, and pairings that define how the vault should be interpreted; then you review the calculated geometric values that will feed the final analytical summary in Step 8.
Where Step 6 establishes the geometry of the intrados lines, Step 7 establishes their meaning: which traces belong together, which bosses they connect to, which ribs should be treated as symmetrical pairs, and which measurements can therefore be compared.
Sub-stages¶
Step 7 is divided into two sequential sub-stages, labelled 7A–7B in the interface:
| Sub-stage | Name | Key action |
|---|---|---|
| 7A | Labelling | Name ribs and boss stones, organise rib groups, define pairings, and set the impost line |
| 7B | Data | Review the calculated rib and boss measurements, inspect diagnostics, and export the results |
The workflow is intentionally ordered: configuration in 7A unlocks interpretation in 7B. You cannot move to the data review tab until the labelling stage has been completed.
Key concepts¶
Trace source : The rib curves used by Step 7. These come from Step 6 and can be taken from the automatic traces, imported manual traces, or both.
Rib group : A single rib or a set of trace segments treated as one structural rib for naming and measurement.
Boss stone : A named rib junction or keystone marker used to identify rib ends and to support apex calculations.
Rib pairing : A user-defined or automatically suggested pairing of two symmetrical ribs or rib groups. Pairings are used to estimate apex heights.
Impost line : The springing reference height against which apex height and impost distance are measured.
What happens in this step¶
Step 7 combines several calculations behind the scenes:
- It loads the selected trace source from Step 6 and the boss markers already associated with the project.
- It estimates rib groups and allows you to refine them manually.
- It fits circular arcs to the rib traces and derives lengths, radii, springing data, and fit errors.
- It calculates impost-based heights and span values once the rib naming and pairing logic is defined.
- It saves a Step 7B summary snapshot for Step 8 when you continue to the next workflow step.
Expected result¶
Before moving on to Step 8 you should have:
- a reviewed set of rib names and boss-stone names
- any necessary rib groups and symmetric pairings defined
- an impost line mode that gives plausible height values
- a checked measurement summary for ribs and bosses
- exported CSV files if you need an external record of the results