PLLENTAB-bgol (Calculate Length by Layer)

Command Type: AutoLISP routine (works in AutoCAD, BricsCAD, ZWCAD and most AutoLISP-compatible CAD platforms)
Developed by: BGol Community, bgol.in

Inspired by the general concept of per-layer length summary utilities used in CAD/survey drafting. This is an original, independently written routine, new file name, new command name, new source code, created so the CAD community has a free, editable, open-source alternative.

Overview

PLEN selects a batch of lines/polylines, sums their length grouped by layer, and writes a simple text summary table into the drawing, replacing a slow, manual, layer-by-layer length tally.

How to Use

1. Load PLLENTAB-bgol.lsp into your CAD session (drag-and-drop the file onto the drawing window, or use the APPLOAD command).
2. Type PLEN at the command line and press Enter.
3. Select the LINE and/or LWPOLYLINE entities you want totaled.
4. Press Enter to finish the selection.
5. Pick a point in the drawing for the results table.
6. A text summary listing each layer name with its cumulative length, plus a grand total, is placed on layer BGOL-PLEN.

Why Use It

• Time savings, automates a manual, layer-by-layer length tally.
• Accuracy, removes human error from manual length summation.
• Quantity takeoffs, per-layer totals are directly usable for material estimates, bill-of-quantities, or reporting.

Where to Use It

• Producing quantity summaries for infrastructure networks (water pipe, drainage line, road length per category).
• Bill-of-quantities preparation where linear measurements need to be totaled and reported by feature type.
• Any CAD workflow needing a quick layer-grouped length summary instead of checking each entity individually.

Notes

• Works on LINE and LWPOLYLINE entities; other entity types are ignored by the selection filter.
• Lengths are summed using each entity's true curve length (via vlax-curve-getDistAtParam), so arc segments within a polyline are measured correctly, not approximated as straight chords.
• The summary is written as plain TEXT rows for maximum compatibility; edit BGOL:PLEN-MakeText if you prefer a native TABLE entity instead.
• Source code is fully open, feel free to study, modify, and redistribute it under the same open, free-for-all spirit.

Credits

Developed and shared for the CAD community by BGol Community. Website: https://bgol.in/ Free and open-source, use it, modify it, share it, for personal or commercial work alike.