DEM.Net.Core

DEM.Net.glTF

This library is licensed for personal use or for smal companies generating less than $100,000 annually, for any other cases, please get in touch with us.

DEM.Net

Digital Elevation Model library in C#

• Elevation queries (point, polylines, heightmap, GPX)
• 3D export (glTF, STL)
• Imagery (MapBox, OSM, Stamen) : textured 3D models and normal maps
• No setup
• Automatic DEM file download from openTopography.org
• Fast and optimized queries

See samples here

Supported by

Supported formats and datasets

Input

• GeoTIFF (JAXA AW3D, and any GeoTIFF)
• HGT (Nasa SRTM)
• netCDF

Output

• glTF
• STL

Current dev status

• All incoming features are listed in the project board here : https://dev.azure.com/dem-net/elevationapi/_workitems/recentlyupdated/.
• Feel free to suggest any idea you'd like to see covered here in the issues : https://github.com/dem-net/DEM.Net/issues.

SampleApp

(Work in progress) SampleApp is a Console App used for test purposes, full of samples. It's pretty messy and lacks documentation but names are self explanatory.

How do I use the API ?

Raster operations

• Use elevationService.DownloadMissingFiles(DEMDataSet.AW3D30, <bbox>) to download and generate metadata for a given dataset.
• Supported datasets : SRTM GL1 and GL3 (HGT files), AWD30 (GeoTIFF)
• Use new RasterService().GenerateReport(DEMDataSet.AW3D30, <bounding box>) to download only necessary tiles using remote VRT file.
• Use rasterService.GenerateFileMetadata(<path to file>, DEMFileFormat.GEOTIFF, false, false) to generate metada for an arbitrary file.
• Use RasterService.GenerateDirectoryMetadata(samplePath);to generate metadata files for your raster tiles. These metadata files will be used as an index when querying Digital Elevation Model data.

Elevation operations

• GetLineGeometryElevation
• GetPointElevation

glTF export

• glTFService can generate triangulated MeshPrimitives from height maps
• Export to .gtlf or .glb

Sample data

• Rasters from http://www.opentopography.org Dataset used is "ALOS World 3D - 30m" : http://opentopo.sdsc.edu/lidar?format=sd&platform=Satellite%20Data&collector=JAXA For development and tests, files covering France were used.
• Not used yet but worth mentionning : For sea bed elevation : ETOPO1 Global Relief Model https://www.ngdc.noaa.gov/mgg/global/global.html

Acknowledgements / Sources

• https://github.com/stefangordon/GeoTiffSharp from @stefangordon which provided a good starting point.
• Pedro Sousa : http://build-failed.blogspot.fr/2014/12/processing-geotiff-files-in-net-without.html for good explanations.
• Mathieu Leplatre for http://blog.mathieu-leplatre.info/drape-lines-on-a-dem-with-postgis.html
• Andy9FromSpace : HGT file reader in https://github.com/Andy9FromSpace/map-elevation

Third party code and librairies

• glTF : glTF2Loader and AssetGenerator : https://github.com/KhronosGroup/glTF
• Tiff support : https://github.com/BitMiracle/libtiff.net
• Serialization : https://github.com/neuecc/ZeroFormatter and https://github.com/JamesNK/Newtonsoft.Json
• System.Numerics.Vectors for Vector support
• GPX reader from dlg.krakow.pl