Travel time over real terrain, solved on click
A real-time isochrone over Estenstadmarka / Jonsvatnet outside Trondheim. A WebGPU compute shader solves the anisotropic eikonal equation on a 455k-cell DEM, giving hiking time from any point, with cost from Tobler's hiking function. The full relaxation converges in a single GPU submit per click, so the isochrone snaps in instantly. Real Kartverket-derived elevation; the backend is static files.
WebGPU not available in this browser
The eikonal solver needs a WebGPU-capable browser (Chrome/Edge 113+, or Safari 18+).
The WGSL source ships in the bundle either way, so open src/hiking.ts to read it.
Plate 05 · eikonal solver · WGSL compute Click or drag the terrain to move the trailhead · right-drag to orbit · scroll to zoom · Terrarium z13 DEM · 3.5× vertical and 5× slope exaggeration for legibility
Happy to walk through any of it.
Also built: embedded systems, moving-map engines, production Rust against Norwegian national geodata, and a live product of my own at solrapport.no.
bjreppen@gmail.com