SPOTPLOT-bgol (Plot Colour-Banded Spot Levels)

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 color-coded spot-level plotting tools used in survey/earthwork workflows (traditionally distributed as spreadsheet macros requiring an Excel-to-CAD clipboard round-trip). This is an original, independently written, entirely AutoLISP-native routine, new file name, new command name, new source code, created so the CAD community has a free, editable, in-drawing alternative that needs no Excel step at all.

Overview

PSLV reads a CSV of survey spot levels (X,Y,Z per row) directly inside your CAD session, automatically buckets each point's elevation into a colour band, plots the elevation value as TEXT at its true coordinate in the matching colour, and draws a simple colour-coded legend, revealing terrain highs and lows across a site at a glance, without ever leaving CAD or pasting data in from Excel.

How to Use

1. Load SPOTPLOT-bgol.lsp into your CAD session (drag-and-drop the file onto the drawing window, or use the APPLOAD command).
2. Type PSLV at the command line and press Enter.
3. Select your source CSV/TXT file. Each line must contain three comma-separated values in order: X,Y,Z (Easting, Northing, Elevation).
4. Enter the number of colour bands when prompted (defaults to 5).
5. Enter the text height for the plotted elevation labels (defaults to 2.5).
6. Pick the legend insertion point in the drawing.
7. Elevation text is plotted at each point's coordinate, coloured according to which band its elevation falls into, all on layer BGOL-PSLV. A stacked colour-coded legend (band range + swatch) is drawn starting at the picked point.

Why Use It

• No Excel round-trip, the original workflow this is inspired by requires opening Excel, running a macro, and pasting into CAD; PSLV does the entire job with one in-drawing command.
• Visual terrain analysis, immediately reveals high and low areas across a survey site by colour, without reading every individual elevation value.
• Automatic banding, colour bands are computed automatically from your data's actual minimum/maximum elevation, with a legend generated to match.

Where to Use It

• Visualizing spot-level (point elevation) survey data across a site to identify low-lying/drainage-prone areas versus high ground.
• Presenting elevation data with an intuitive colour-coded legend for client or stakeholder review.
• Any earthwork, drainage, or topographic analysis task benefiting from an at-a-glance visual elevation range map plotted directly at each survey point's true coordinate.

Notes

• Colour bands are evenly spaced between the data's actual minimum and maximum elevation, using AutoCAD colour indices 1-9 (cycling if more than 9 bands are requested).
• The legend is drawn as a column of coloured swatches (small filled rectangles) each labeled with its elevation range, stacked upward from the picked insertion point.
• This is a from-scratch, AutoLISP-native re-implementation of the underlying idea, it does not use or require the original Excel/VBA macro file.
• 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.