DWG Comparison Tool
Two progress drawings, overlaid. Removals and additions are found and coloured automatically, and the net quantity for the period is calculated.
General
- Platform
- Civil 3D
01Drawings
Pick a period
02Two drawings
03Net quantitiesPU-07 → PU-08
| Item | PU-07 | PU-08 | Added | Removed | Net this period |
|---|---|---|---|---|---|
| Asphalt wearing coursePRG-ASPHALT | 3,960.00 m² | 6,987.00 m² | +3,027.00 m² | 0 | +3,027.00 m² |
| KerbsPRG-KERB | 1,010.00 lm | 1,530.46 lm | +560.46 lm | −40.00 lm | +520.46 lm |
| Storm drain pipePRG-STORM-PIPE | 360.00 lm | 400.00 lm | +40.00 lm | 0 | +40.00 lm |
| ManholesPRG-STORM-MH | 10 nr | 11 nr | +1 nr | 0 | +1 nr |
| Street lightsPRG-LIGHTING | 6 nr | 9 nr | +4 nr | −1 nr | +3 nr |
The idea
Every progress update starts with the same question: what changed since the last one?
Done by hand, that means opening two drawings side by side and hunting for the differences: which kerbs are new, which asphalt areas were extended, and whether anything that was reported last time has since been taken out or redrawn. It is slow, and a single missed object makes the progress quantities wrong.
The DWG Comparison Tool, part of my custom Civil 3D tools, does it the other way round. It lays the previous and the current progress drawings on top of each other and compares every object. Whatever is only in the previous drawing was taken out (red). Whatever is only in the current drawing was added (green). Everything else is unchanged. The net quantity for the period follows directly, and goes into the report.
How it works
- Previous progress drawing (DWG)
- Current progress drawing (DWG)
- Overlay: both drawings in the same coordinates
- Every object compared: taken out, added or unchanged
- Net quantity per item = added − removed
- Progress report
Why it helps with periodic updates
- No searching by eye. The differences are found for you, however large the drawing.
- Removals count too. Work that was redrawn, corrected or taken out comes off the quantity instead of hiding in the total.
- It always adds up. Previous quantity + net for the period = current quantity, for every item, every update.
About the demonstration
The demonstration above runs entirely in your browser. It uses four synthetic progress drawings of a simplified road scheme, two weeks apart, including a kerb that was drawn before it was built and a bus bay that replaced a straight kerb. In the demonstration, objects are matched by layer and geometry.