TIN Generator
Upload point data to generate a Triangulated Irregular Network (TIN) using Delaunay triangulation. Optionally assign a Z value for elevation. Download as GeoJSON, DXF, or Shapefile.
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GeoJSON, KML, GPX — point features only
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What is a TIN?
A Triangulated Irregular Network (TIN) is a vector representation of a surface made up of non-overlapping triangles. Each triangle connects three data points, and together the triangles cover the entire area defined by the input points. TINs are the standard data structure for terrain modelling in engineering and GIS.
This tool uses Delaunay triangulation — an algorithm that connects points into triangles while maximising the minimum angle of each triangle. This avoids sliver triangles and produces a surface that interpolates smoothly between data points, making it ideal for elevation modelling, geotechnical analysis, and point cloud visualisation.
Common use cases
Terrain modelling
Build a triangulated surface from survey elevation points or LiDAR-derived ground points for slope, aspect, and volume analysis.
Geotechnical analysis
Triangulate borehole or CPT test point locations to model subsurface conditions across a site.
Point cloud visualisation
Convert a sparse point cloud to a mesh of triangles for 3D rendering in GIS or CAD software.
Contour generation
Use the triangulated surface as the basis for generating elevation contour lines in QGIS or similar tools.
Frequently asked questions
What is the Delaunay property and why does it matter?
The Delaunay triangulation maximises the minimum angle of all triangles — it avoids thin, elongated ("sliver") triangles that produce poor surface models. This makes Delaunay TINs the standard choice for terrain modelling because they interpolate elevation smoothly across the surface.
Do I need elevation (Z) values in my point data?
No — the triangulation is computed from the X/Y positions regardless of whether Z values are present. If your points have an elevation attribute or Z coordinate, those values are included in the output triangles, enabling 3D surface analysis.
What is the difference between a TIN and a raster DEM?
A TIN represents terrain as a network of triangles with vertices at the original data points, preserving all input locations exactly. A raster DEM interpolates elevation to a regular grid of cells. TINs are more accurate at data points but harder to process in raster analysis pipelines.
What output formats are supported?
The TIN Generator outputs GeoJSON (triangle polygons), DXF (for CAD software), and Shapefile (ZIP). DXF is useful for importing the triangulation into AutoCAD or Civil 3D for engineering workflows.