How to Compare Drawings in BricsCAD

Quick answer: DWGCOMPARE starts a comparison session between the current drawing and another one you select, colour-coding what’s missing, modified, or new. ENDCOMPARE finishes the session, and KEEPME merges the compared drawings visually. Comparison results also show up as their own node in the Structure panel for closer review.

The Three Comparison Commands

DWGCOMPARE: starts a comparison session between the current drawing and a drawing you select.
ENDCOMPARE: ends the comparison session.
KEEPME: merges the compared drawings visually, adding changed entities into the source drawing.

Comparison Settings

Variable	Controls	Default
`CMPCLRMISS`	Colour of missing entities	Red
`CMPCLRMOD1`	Colour of modified entities	Index colour 253
`CMPCLRMOD2`	Colour of modified entities in the second drawing	Yellow
`CMPCLRNEW`	Colour of new entities	Green
`CMPDIFFLIMIT`	Maximum entities to compare before the comparison aborts; accepts 1 to 10,000,000	10,000,000
`CMPFADECTL`	Fade level for unmodified entities	80
`CMPLOG`	Whether a log report gets created	Off

Running a Comparison

Run DWGCOMPARE. You’re prompted with the current comparison limit and asked to Select a file or set a new Limit.
Optionally choose Limit to change the entity comparison cap first.
Choose Select to open the file picker.
Choose the drawing to compare against and click Open (or double-click it). The Compare panel and Compare toolbar appear.
Click End compare in the Compare panel when you’re done.

Reviewing Results in the Structure Panel

While a comparison is running, load the Default.cst configuration in the Structure panel and expand the Comparison node. Four subnodes appear, each labelled with its entity count: Missing, Modified (Original), New, and Modified (Compared).

From there:

Click a subnode to select all its entities in the drawing.
Expand a subnode and click an individual entity to highlight just that one (hold Ctrl to select several).
Right-click and choose Zoom to zoom to whatever’s selected.

Frequently Asked Questions

What colour means what during a comparison? By default: red for missing entities, yellow for entities modified in the second drawing, green for new entities, and index colour 253 for entities modified overall.

Is there a limit to how many entities BricsCAD can compare? Yes, CMPDIFFLIMIT caps it, accepting values from 1 to 10,000,000, and the comparison aborts if that limit is reached.

How do I merge changes from the compared drawing back into my current one? Use the KEEPME command, which visually merges the two and adds changed entities into the source drawing.

Can I keep a record of what a comparison found? Yes, turn on CMPLOG (it’s off by default) to generate a log report of the comparison.