France: 0.5 meter DSM - Institut national de l'information géographique et forestière (IGN)

You can use the Plex-Earth features to create terrain models from free, quality data you can find online.

About the Data

Data Provider: IGN - Institut national de l'information géographique et forestière (France)

Link: https://geoservices.ign.fr/modeles-numeriques-de-surfaces-correles

Data Type: DSM (Digital Surface Model)

Resolution: Sampling Interval 0.5 m

License/Terms: IGN Open Licence (reuse allowed with attribution)

Documentation:https://geoservices.ign.fr/documentation/donnees/alti/modeles-numeriques-de-surfaces-correles

Data Download

1. Visit the data URL: https://geoservices.ign.fr/modeles-numeriques-de-surfaces-correles

   

   
   When you scroll down, you will see multiple download links for your data, per France's district departments. Scroll until you find the district of interest and click on the respective link(s) for the download to start. Files are large, so the download might take some time.

   Map of France's departments

   

2. Right-click the downloaded zip folder and extract all the folders.

3. Select the proper GeoTIFF for your area: Open the folder, and then navigate to the first file

   

   
   You will see a list of multiple TIFFs, so you need to select the proper one for your area. To do so, we need to break down the parameters of the name of each file. To understand this, check the following example: 
   75-2024-0659-6860-LA93-0M50.tif

   Segment	Meaning
   75	Department number (75 = Paris)
   2024	The year of production or dataset version
   0659	X index in Lambert 93 1km grid → corresponds to 659,000 m
   6860	Y index in Lambert 93 1km grid → corresponds to 6,860,000 m
   LA93	Lambert 93 projection
   0M50	0.5 meter resolution

   The next step would be to find the right tile by converting your area's lat, long coordinates to X, Y of Lambert 93 Projection: 
   a. Locate your area in Google Earth or Google Maps and note its Lat/Long coordinates

   

   
   For our example: Lat: 48.818520°, Long: 2.346542°
   b) Convert Lat/Long to X, Y of Lambert 93 Projection.  Use any converter, such as EPSG.io.

   

   For input, use Lat/Long, and use projection Lambert 93 for output, then Transform.

   Then, take the output coordinates.

   X: 652018.8479442275

   Y: 6857804.591243857

   Since the grid is by 1 km, divide the values by 1000, and the result will be the following:

   X: 0652

   Y: 6858
    

   Round off to the proper digit!

   With the above calculations, the correct folder for our area would be:

   75-2024-0652-6858-LA93-0M50.tif

Use Data for Terrain Model creation

After downloading the data, you can now proceed with creating a terrain model in CAD.

1. In AutoCAD or BricsCAD, go to the Plex-Earth ribbon → click on the Create Terrain dropdown box → Terrain from GeoTIFF → load the GeoTIFF downloaded.

2. In the Import GeoTIFF palette, specify the area by clicking on the Select Area button, then use your mouse cursor to draw a rectangle, and select the desired resolution using the slider.

3. Click on the Import Terrain button

4. Select the Surface Type from the options available:

   • Contour Polylines

   • Points

   • TIN Mesh

   • Civil 3D Surface

   • Create Terrain Model

For the first four options, CAD objects are directly imported, ready to be used in CAD or other software.

The last option creates a Plex-Earth terrain model, which can be saved in your DWG, and with the help of Plex-Earth, customize the terrain further and also insert the data as CAD objects later on.

Check out the full guide here: Create Terrain from GeoTIFF

Here is the result!