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Lilien Auger

Co-founder

Dev & AI Engineer

Work

Lilien co-founded TerraLab and codes on all of it: the three QGIS plugins, the AI models behind them, and the servers those models run on. He also runs marketing and operations, answers the mail users send and takes the calls they book.

Background

42 Paris alumnus. He was an AI engineer at Publicis before TerraLab. His open-source work has passed 500 GitHub stars.

Elsewhere

Meet the rest of the team

Posts by Lilien Auger

A dark card titled Claude for QGIS, three routes compared. Route 1, chat window: Claude writes PyQGIS, you paste it into the Python console, nothing to install. Route 2, QGIS MCP: Claude Desktop or Claude Code runs QGIS tools itself, plugin plus uv plus a config entry. Route 3, in green, agent in QGIS: a chat panel inside QGIS reads the project and does the steps, one plugin.

AI AgentQGISGuide

Claude for QGIS: 3 Ways to Use It, Compared

Three ways to use Claude with QGIS: PyQGIS from a chat, Claude Desktop or Claude Code through QGIS MCP, or an agent inside QGIS. Setup, limits, which to pick.

Grid of 28 AI plugin names for QGIS: 18 with a green tick, listed for QGIS 4, SamGeo with a dashed outline, and 9 in grey, among them Mapflow and Deepness. Source plugins.qgis.org, 2026-11-11.

QGIS 4 AI Plugins: 18 of 28 Listed as Compatible

On 11 November 2026, 18 of 28 AI plugins for QGIS are listed as compatible with QGIS 4. Mapflow and Deepness are not. The table, read from plugins.qgis.org.

Nolli's 1748 plan of Rome, buildings hatched dark and public space, streets and church interiors left white.

AI EditQGISTutorial

Figure Ground Map: What It Is and How to Make One

A figure ground map shows buildings in black and the rest in white. How to make one in QGIS from open footprints, or from an aerial image without them.

Central Angers on the IGN orthophoto, with the cadastral parcels outlined in purple and numbered, loaded in QGIS from the Geoplateforme WMS.

AI AgentQGISTutorial

IGN WMS and WMTS in QGIS: Geoplateforme URLs, Layers, Fixes

The IGN Geoplateforme URLs that answer on 19 October 2026, the exact layer names, WMS vs WMTS measured in QGIS, and why a French layer stays blank.

New infill housing on Kay Street, a row of houses built on a gap in an existing terrace.

AI EditQGISGuide

Urban Infill: What It Is, and Three Scenarios on One Lot

Urban infill means building on vacant or underused land inside a city. The five kinds of lot, how to find them in QGIS, and one lot rendered three ways.

Aerial image of Glenwood High School in Chatham, Illinois. A black ring marks the official school point on the building, an orange Nominatim point sits 17 m away, and a pink Census point sits 184 m south on Plummer Boulevard.

AI AgentQGISTutorial

Geocoding in QGIS: 5 Free Ways Compared on Real Addresses

How to geocode addresses in QGIS for free with Nominatim, MMQGIS, the US Census and the French BAN, with match rates and errors measured on 200 real schools.

A finished A4 map titled Paris: population density by arrondissement. The 20 arrondissements are shaded from pale pink to dark red, the 11th darkest, with a legend in people per km², a 0 to 4 km scale bar, a north arrow and a data source line.

AI AgentQGISTutorial

How to Make a Map in QGIS: Step by Step, Then With AI

Make a map in QGIS 3.44 from open data: style it, label it, build a print layout with legend, scale bar and north arrow, export it. Then the same map by AI.

A 3D view of Paris blocks around the Batignolles, each building raised to its measured height and coloured from pale yellow to dark red, beside the figure 3.07 m, the median height per story measured on 243,603 buildings.

Open DataQGISGuide

How Tall Is a Story? 10 Feet, Measured on 307,225 Buildings

One story is 3.07 m (10.1 ft) floor to floor at the median. Heights for 1 to 12 stories: a 5-story building stands 16.2 m (53 ft), a 10-story one 27 m (89 ft).

The same dense block of Dandora, Nairobi, on April 2026 drone imagery, cut into four vertical strips, each carrying one dataset's building outlines: orange Microsoft rectangles, yellow Google rectangles, magenta Overture outlines and blue OpenStreetMap outlines that follow the roofs.

Open DataQGISGuide

Microsoft Building Footprints vs Google vs Overture, Tested

Microsoft matched 25% of a French town's cadastre buildings, OpenStreetMap 83%. Then Nairobi: five free sources, timed downloads, checked on drone imagery.

Hillshaded relief of a forested slope and the valley floor at Bagnères-de-Luchon, France, split in two: blurred on the left from the 30 m Copernicus DEM, sharp on the right from IGN's 1 m LiDAR HD model, with roads and a river visible, under the title Free DEM in QGIS.

Open DataQGISTutorial

Free DEM Download: SRTM, Copernicus and LiDAR in QGIS

Over one Pyrenean valley, four free 30 m DEMs sat 12 to 18 m above the LiDAR ground under forest. Where to get each DEM free, and how to load it in QGIS.

The same view of central Paris cut in three vertical strips: 6,041 bike crashes as red dots on a grey street map, the same crashes as a yellow to red heat map with a red cross at Châtelet, and as orange hexagons coloured by crash count, under the title Heat maps in QGIS.

How to Make a Heat Map in QGIS (and With One Prompt)

6,041 bike crashes in Paris mapped three ways in QGIS: Heatmap renderer, kernel density raster and hexagons, then one sentence to an AI agent: 2 min 34 s.

Aerial photo of the old town of Nice with the Parc du Château polygon in yellow and other city parks in pale green, beside the KML text of that park's placemark: its name, its HTML description, its style and its longitude, latitude and altitude coordinates.

What Is a KML File? How to Open, Edit and Convert It Free

KML is map data written as XML; a KMZ is the zipped form. Open it in Google Earth or QGIS, find attributes hidden in HTML, convert to Shapefile, CSV or GeoJSON.

Sentinel-2 true colour image near Querência, Mato Grosso, Brazil: dense Amazon forest on the right, green and pale crop fields, bare pink fields and a wetland river on the left.

NDVI vs EVI, SAVI, NDRE and NDWI: Formulas for QGIS

NDVI flattens out over dense canopy. EVI, SAVI, NDRE, NDWI and NDMI each fix a blind spot. Raster Calculator formulas and a measured test in Brazil.

The same block of houses with swimming pools in Tournefeuille, France, in three vertical strips: sharp at 20 cm, blocky at 3 m and an unreadable mosaic of 10 m Sentinel-2 pixels.

AI SegmentationQGISGuide

Satellite Image Resolution Compared: 30 m to 30 cm, Free vs Paid

8 sources from Landsat to Pléiades Neo, with price and revisit. On one suburb, 0.2% of buildings cover 16 pixels at 10 m and 96% at 50 cm, of 20,911 counted.

The same fields and industrial estate west of Rennes, France, on 29 July 2026: sharp at 10 m from Sentinel-2 on the left, blocky at 30 m from Landsat 9 on the right.

Sentinel-2 vs Landsat 8 and 9: Bands, Resolution, Clear Days

10 m vs 30 m, 5-day vs 8-day revisit, 13 vs 11 bands. Over one year near Rennes, Sentinel-2 gave 53 clear days and Landsat 30, with waits up to 33 vs 79 days.

Map of France with communes coloured by LiDAR HD flight year, 2021 to 2026, grey where the cloud is not published.

Open DataQGISTutorial

LiDAR HD from IGN: download and open in QGIS

The classified LiDAR HD cloud covered 78.4% of France on 6 September 2026, 30,933 of 34,877 communes. Map per commune, products, clicks in QGIS.

A LiDAR HD point cloud from the French national survey, coloured by class, over the Bibliothèque nationale de France.

Photogrammetry vs LiDAR: Which One for Which Job

Photogrammetry rebuilds a surface from overlapping photos. LiDAR measures it with a laser. One gives colour and a cheap flight, the other sees under the trees.

A Sentinel-2 false colour image of the Ravenna floods of May 2023, vegetation in red and flood water in dark blue.

Multispectral vs Hyperspectral: Bands, Cost and Free Data

Multispectral records 4 to 13 wide bands, hyperspectral 100 to 300 narrow ones. A table of bands, free satellites, drone sensor cost and data size.

An architect's site plan of Bartow Station, drawn to scale with the building, the tracks and the property lines.

AI EditQGISGuide

Plot Plan vs Site Plan: The 8 Items 19 Permit Offices Check

A plot plan draws one lot, a site plan the whole project. The 8 items 19 US permit checklists ask for, who can draw a plot plan, and how to make one in QGIS.

Drone photograph looking straight down on the church and village centre of Ebing, Bavaria.

Orthophoto vs Orthomosaic: The Difference, and 7 Free for QGIS

An orthophoto is one corrected photo; an orthomosaic stitches many. How each is made, why one drew Berlin's TV tower 127 m off, and 7 free national services.

Building footprints of Shivajinagar, Bengaluru, each building its own polygon on a dense grid of streets.

AI SegmentationGeoAIGuide

Semantic vs Instance vs Panoptic Segmentation: The Difference

Semantic segmentation labels every pixel with a class: building or not. Instance segmentation draws every building as its own object.

The Gas Works Park site in Seattle in 1973, a former gasworks on the lake shore before it became a park.

AI EditQGISGuide

Greenfield vs Brownfield: Project, Software and Land Meaning

Greenfield starts from nothing, brownfield builds on what exists. What it means for a project, for IT and for land, with 314 real sites counted.

The QGIS interface with a choropleth map of median income in Houston, the layer panel on the left.

AI SegmentationQGISTutorial

How to Add a Basemap in QGIS: XYZ, WMS, QuickMapServices

Browser panel > XYZ Tiles > double-click OpenStreetMap. Then satellite tiles by URL, QuickMapServices, a national WMS, and the ground size of each zoom.

Coloured LiDAR hillshade of drumlins near Hood Canal, Washington, the bare ground with the forest removed.

DSM vs DTM vs DEM: The Difference, Measured, and Free Downloads

A DSM is the top of everything, a DTM bare ground, a DEM either. On one town tile the DSM made 41% of the ground steeper than 30°, the DTM 7%. 8 free sources.

A glossy colored site plan of Broadway Gardens, Letchworth: warm grey buildings with drop shadows, charcoal roads, green lawns and round tree canopies.

AI EditQGISTutorial

Colored site plan: the same block four ways

Flat, watercolor, pencil and glossy, all rendered from one aerial image of Letchworth Garden City. Every prompt in full, and where the model invented water.

A flat architectural site plan of Broadway Gardens, Letchworth, generated from satellite imagery: white building footprints, grey roads, green lawns and tree canopies.

AI EditQGISTutorial

Turn a Satellite Image into a Site Plan in QGIS

Load imagery in QGIS, draw a zone, and get a georeferenced four-class site plan back in under a minute. The manual route, the AI route, and where each breaks.

An aerial view of Besançon with the Doubs in flood, brown water covering the quays and the riverside park.

QGISGeoAIAI Edit

How to Simulate a Flood in QGIS: 5 Methods

From the official hazard map to a generated aerial view of the water. Which method gives a number, which gives a picture, why an elevation model changes both.

Aerial view of apartment blocks generated on former car parks, with the title Google Earth AI alternative.

QGISGeoAIAI Edit

Google Earth AI Alternative for QGIS

Google pulled image generation from Google Earth after one day. AI Edit runs the same Nano Banana model inside QGIS and returns a map layer, not a screenshot.

An aerial view of a commercial strip road rebuilt with cycle tracks, street trees and planted forecourts.

QGISGeoAIAI Edit

How to Redesign a Street in QGIS: 5 Methods

Five ways to show a street rebuilt, from hand-drawn vector layers to a generated aerial view. Only one gives back a picture that stays on the map.

AI Segmentation in QGIS: aerial imagery on the left, AI-detected building polygons on the right.

AI SegmentationQGISTutorial

AI Segmentation for QGIS: The Complete Guide

Draw a zone, name the object, get every polygon as a clean vector layer. The full run in QGIS, the three-step review in any order, and Semi-Auto mode.