turf.triangleGrid

What is turf.triangleGrid?

turf.triangleGrid covers a bounding box with a lattice of triangular polygons and returns them as a FeatureCollection<Polygon>. Each cellSide × cellSide square is filled with two triangles.

turf.triangleGrid(bbox, cellSide, options?) → FeatureCollection<Polygon>

Options include:

• units — units for cellSide (default 'kilometers')
• mask — a Polygon or MultiPolygon; cells whose centre lies outside the mask are dropped
• properties — properties attached to every cell

When would you use turf.triangleGrid?

Use turf.triangleGrid for scientific visualisation, finite-element-style simulations on a map, or when you need a ready-made triangulation to feed into shaders or custom interpolation. It is also a common aesthetic choice for stylised thematic maps.

For most spatial binning tasks, hex grids are preferable — triangular bins are less intuitive to read and their small area per cell can fragment data. Reach for triangleGrid when you specifically need triangles.

1const bbox = [-122.6, 37.6, -122.3, 37.9];
2const tris = turf.triangleGrid(bbox, 0.5, { units: 'kilometers' });

FAQs

How do I install Turf.js to use this function?

Install npm install @turf/triangle-grid and import import { triangleGrid } from '@turf/triangle-grid', or use turf.triangleGrid via @turf/turf.

How many triangles does one cellSide produce?

Two triangles per cellSide × cellSide square. So a grid covering a 10×10 cellSide bbox yields roughly 200 triangles.

Can I restrict the grid to an arbitrary polygon?

Yes, via options.mask. Triangles whose centroid lies outside the mask are omitted, which is faster than post-filtering the full grid.

Do triangles in triangleGrid form a TIN?

Not a Delaunay TIN — they form a regular lattice. If you need a triangulation over scattered points (with z-values), use turf.tin instead.