Compare two drawings
File ▸ Compare… (command COMPARE) shows what changed between an original drawing and a revised one. The result opens in a new tab, so neither source drawing is touched.
Run a compare
- Choose File ▸ Compare…, or type COMPARE.
- In the Compare drawings dialog, pick Original (A) and Revised (B). Each can be an open tab, or press File… beside the list to load a drawing from disk. The two must be different drawings.
- Choose how to Align A to B: Automatic, None (compare where they are), or Pick points (you click a base point, and optionally a second point, in A and then in B).
- Adjust Tolerance and Group distance if needed (both are in drawing units; the defaults suit the units of B). Use Ignore layers… to leave out layers of B, such as a revision table.
- Press Compare. A progress message appears with a Cancel button.
Note
If B has no units set, the program asks what one drawing unit means before comparing, because the tolerance and group distance depend on it. See Open files and units.
Reading the result
| Colour | Meaning |
|---|---|
| Grey | Unchanged |
| Green | Added (only in B) |
| Red | Removed (only in A) |
| Amber | Changed in shape or position |
Each group of nearby changes is framed by a dotted rectangle. Revision clouds are deliberately not used, so the sheet stays readable.
The Compare panel
The side panel (In the app: Help ▸ Show me) lists the counts and the change groups.
- Previous and Next zoom to each change in turn.
- View switches between Differences, Overlay, A only and B only.
- Show property-only changes draws objects that differ only in colour, linetype, lineweight or layer, as faint dashed grey on layer COMPARE-PROPS.
- Legend on sheet draws the legend below the drawing so it appears on the plot.
- Copy list and Export CSV… save the change list (group, change, layer, object type, X, Y, details).
- Plot to PDF… opens the Plot dialog for the compare drawing.
Tip
The result is an ordinary drawing in its own tab. See Layers and Tabs and sessions.
Note
While a compare is running, the tabs of A and B cannot be closed, and a second compare cannot start. Wait for it to finish or cancel it.