A plain-language guide to the QGIS plugin: what the buttons do, how to load excavation points, and how to export a true-scale figure. Button names match the English screen.
Not the same text as ARSYSplotLite’s i help. Both tools share the same reading ideas (plan + sections, Stretch Z, density, paper 1∶N), but this page describes the plugin workspace. The Lite i modal describes the browser app.
ARSYSplotQGIS helps you read excavation XYZ points in space: where finds sit in plan, and how they stack in depth — inside QGIS, without drawing on the main map.
On one workspace you see three linked drawings:
Plan — looking down (left–right = X, up–down = Y)
Longitudinal — vertical cut along X, with height Z
Transversal — vertical cut along Y, with height Z
You can colour by material or level, hide groups, keep only a depth slice, exaggerate Z on sections (Stretch Z), show kernel density, search a record, open a large Zoom window or a simple 3D scatter, and export a paper figure at a real scale (for example 1∶50 with a 50 cm scale bar).
The plugin opens its own window. Nothing is added to the QGIS map canvas or layer legend. Your project layers are never modified when you “Use selected layer” (a private copy is made).
Everyday tip
Load the sample, turn Cross-view On, hover a flint in plan, and watch the blue mark appear on both sections. That is the same find in three projections.
Dark / Light — workspace chrome only. Paper export stays on a white sheet.
? — this help.
Load Data — Import CSV, Load sample, or Use selected layer.
Group — which field colours the points, chips to show/hide values, Load style… / Clear.
Options — tabs General, Density, Find, Profile. Footer: Reset, To QGIS layer, Open 3D view.
Right side
Three drawing panes (Plan / Long / Trans) with Zoom, Fit and Export on each.
Resources — Filter (X/Y/Z dual ranges), Stretch Z, Cross-view, Density scale when density is on, and Profile export (CSV / To QGIS) when a profile is active.
Moving around a drawing
Mouse wheel = zoom; drag = pan; Fit recentres on the data frame.
Zoom opens a large floating window of that pane (Esc closes).
With Point info on, rest on a point to see its attributes.
Quick start
1. Press Load sample. 2. Toggle a few Group chips. 3. Under Resources, narrow Z a little. 4. Optional: open Options → Density (or Profile). 5. Export Plan at 1∶50 when you like what you see.
Import — first choose File type (CSV or Spreadsheet), then Choose file…. For Excel/ODS pick the Sheet, then map P1/P2/P3/Group. Spreadsheets use QGIS GDAL/OGR (no extra packages).
Load sample — bundled sample.csv (~2 500 points) to try the tool.
Use selected layer — copies the current QGIS point layer into the private workspace.
After data are loaded, Options footer → To QGIS layer sends the full table (all attributes; plugin filters ignored) to the project as a memory point layer for Processing / GRASS. Save it yourself (GeoPackage…) if you want it after closing QGIS. Not under Load Data — that row only brings data in.
What every row needs
To draw a point you need position in space. In ArcheSystem language:
p1x — left–right (X)
p1y — forward–back (Y)
p1z — height / depth (Z); if missing, treated as 0 so the point can still appear in plan
Optional: P2 and P3 for an orientation axis. After import, drawing always uses P1 as the point and P2→P3 as the vector:
P1 only — point; no vector.
P1 + P2, no P3 — file stored P1→P2; the plugin stores P1 as the midpoint and the axis as P2→P3.
P1 + P2 + P3 — unchanged.
Extra CSV columns stay as attributes (useful for Group and Find).
Sample file
Default Group after Load sample is material. P2/P3 are filled mainly for nivell = 1. Set Draw → Vectors or Both, then filter that level if you want to see orientation axes.
Field — which attribute colours markers (material, level, taxon…).
Coloured chips — click to hide or show a value. Empty values appear as (empty).
All / None — show everything or clear the view quickly.
Load style… — optional UTF-8 text file: colour and Point model shape per value (see sample_style.txt). Clear removes it.
Style format: a bare line starts a field section; then value;colour or value;colour;shape. A flat list before any section applies to the active Group field.
Three dual sliders keep only points inside X, Y and Z ranges. Reset under Filter restores full X/Y/Z only — it does not change Point size, Draw, groups, Density or Stretch Z.
Stretch Z
Off by default. Vertical exaggeration on Longitudinal and Transversal only. Plan stays true scale.
On + Factor — 1 = true; 5 = height drawn five times taller than X/Y.
Tick labels stay in real metres; the axis title shows e.g. Z ×5 (m).
Applies to screen, Zoom windows, density on sections, and paper export of those panes.
The paper scale bar uses the horizontal axis only (true map metres).
Reset sets Factor back to 1.
When to use Stretch Z
A 15 cm occupation layer looks flat on a long trench. ×5 opens the layer vertically while X (or Y) stays readable in metres.
Cross-view
Off by default. With On, the record under the mouse on one main pane is marked on the other two (shared real XYZ). Zoom windows are not driven by this.
Density scale
When Density is on, Resources shows the colour scale and Invert. When Profile is active, Resources also shows Profile export (CSV and To QGIS for LONG/TRANS).
Kernel density of the currently filtered points (QGIS Processing heatmap). It is an exploratory surface, not a publication statistic by itself. Open the Density tab to build the surface (no On switch). Density and Profile cannot show together — selecting Density parks the profile (A/B kept); selecting Profile restores it and hides density. Opening General leaves them alone; use Redraw on the General tab to park Density and Profile and show the loaded data.
Show — Heatmap, Isolines, or Both.
Fill — Bands (discrete classes) or Cloud (smooth). Same KDE underneath.
Colour — palette (Archeo, Viridis…). Invert is under Resources.
Min / Max + Auto — colour stretch. Auto ≈ 2% cut of positive plan cells / peak. Below Min is not painted.
Radius + Auto — how far each point “spreads”; Auto also suggests Cell.
Plan and sections do not share absolute KDE units. Sections shrink Radius/Cell so a circular kernel does not explode along short Z. Change Stretch Z with density on: the surface is rebuilt to stay aligned with the points.
Starting suggestion
Open Density → Auto (Radius/Cell) → Heatmap + Bands → try Both if you want isolines on top. Start with Quartic.
Options → Profile cuts a vertical prism through the cloud using a line on Plan.
Wide (cm) — horizontal width of the profile in XY (perpendicular to A→B). Default 10 cm, step 1 cm. Not a Z thickness.
Open the tab → blinking cue on the Plan title bar asks for A (red), then B (blue). Click Plan (or type X/Y). After B, LONG/TRANS update automatically.
Once placed, drag A or B on Plan (open-hand cursor) to move them; the profile follows live and sections rebuild when you release.
New Profile — clears A/B/overlay and starts Pick A again.
Records in the profile (Group ∩ Resources) fill LONG = dominant Plan axis × Z and TRANS = the other Plan axis × Z (same tick style as Plan — numbers on X, letters on Y; whole-metre frames). Thin levels auto-enable Stretch Z so the section is readable. Plan shows a green profile band; A (red) and B (blue) are labeled.
While Profile is active, Resources → Profile export:
Export CSV… — site points in the profile (attributes + X/Y/Z + dist. A→B + offset). Default name original_SelectedProfile_YYYYMMDD.csv.
To QGIS… — one point memory layer per chosen section (LONG and/or TRANS), same geometry as on screen. Does not export Plan XY or vectors. Save as GeoPackage to keep them.
Profile and Density are mutually exclusive on screen (selecting one tab hides the other). General → Redraw parks both and shows the loaded data. A/B/Wide are kept when you open Density or use Redraw, so returning to Profile restores the same cut. New Profile clears them.
Each pane (or its Zoom window) has Export. The dialog builds a true-scale paper figure of the data frame — not a casual screenshot. Title: Export · Plan (or Longitudinal / Transversal).
PNG or SVG; paper A5 / A4 / A3; portrait or landscape. Sheet always white.
Scale — Automatic (neat 1∶N that fits) or Custom 1∶N (default N = 20; any N allowed). Custom keeps N and shows the computed drawn size.
Frame — closed rectangle around the data footprint (not only L-axes).
Grid — metre / excavation-square lines a little thicker than the frame so cells stay readable.
Scale bar — prefers a fixed 50 cm black/white bar; at extreme 1∶N picks another readable length. 1∶N sits next to the bar.
Include legend (default on) — group colour + Point model glyph. Beside the frame when there is room, otherwise below in columns.
Optional title / subtitle; optional plot-area fill inside the axes only.
PNG resolution 96 / 150 / 300 / 600 dpi (also used for density sampling on paper).
Density on the figure matches the screen (Stretch Z, Min/Max, Invert…).
Example
Pin attention on Longitudinal, Stretch Z ×5, Density Both, then Export → A4 landscape → 1∶50 → PNG with legend. Drop the file into the report.
Does not paint layers on the QGIS map or replace full ARSYSplot.
3D is a lightweight Qt scatter — not the QGIS 3D engine.
No dedicated Arche10 mode (many Arche10 exports still open as CSV). Lite covers Arche10 / Excel units UI in the browser; the plugin uses OGR for xlsx/ods/xls.
Density is exploratory visualisation of the filtered sample — document which subset you used.
Needs QGIS 3.22+ (tested on 3.40 / 3.44), Processing Heatmap and Contour. Licence: GNU GPL-2.0-or-later. Suite: ArcheSystem · Analytics.