Battlefield Overview.

A common operating picture on real ground — BLUEFOR and OPFOR maneuvering across the JMRC training area at Hohenfels, Germany. Real terrain, real roads, rendered entirely in the browser with nothing streamed.

Canvas 2D SRTM Terrain OpenStreetMap Offline Vanilla JS

Demo only, not final product

why it works

Marketing Slop.

100%

Offline

Terrain and roads are baked at build time into the page itself. No tile servers, no API keys, no network at runtime — it runs on an air-gapped laptop.

REAL

Ground Truth

Elevation from SRTM and the road network from OpenStreetMap — the actual Hohenfels terrain and trace, not a stylized stand-in.

Two Forces

BLUEFOR and OPFOR move as convoys along the road net, hold in assembly areas, and screen key terrain — the shape of a rotation at a glance.

Dependencies

Pure Canvas 2D. No Three.js, no map library, no framework — one file, a few hundred lines, drops into any page.

Oblique View

A slow drone-angle camera over slope-shaded terrain — the operational picture reads as ground, not a flat map.

∞

Any AO

Swap the bbox and re-bake — the same engine renders any training area or operating environment on Earth.

how it works

Nerd Out.

Offline data bake — a build step pulls AWS terrarium elevation tiles and the OSM road network for the Hohenfels box, samples a 96×96 heightfield, simplifies the roads, and inlines both as compact JSON. Nothing is fetched when the page runs.
Terrain — bilinear h(x,y) over the heightfield, exaggerated for relief, meshed into slope-shaded quads that are painter-sorted back-to-front each frame so ridgelines occlude correctly.
Camera — a single oblique projection (~35° from the deck) with a slow yaw drift; world points [x, elev, z] map straight to screen, so terrain, roads, and units all share one transform.
Roads → routes — every OSM polyline is converted to world space and given a cumulative arc-length table, so posAt(route, s) returns a position and heading anywhere along it.
Convoys — a leader advances its distance s along a route; followers sit at s − k·spacing, so the whole column tracks the road through every bend. Static elements hold in assembly areas keyed to real settlements.
Lineage — the renderer is lifted from earlier airfield sector sims (the same offline terrain + 3D-entity engine), repointed from Sierra Vista to a NATO training area to prove it travels.

lessons learned

The takeaway.

A rotation at the JMRC is thousands of moving parts across forty square kilometers of Bavarian hills. The picture that ties it together — who is where, moving which way — usually lives on a streamed tactical map that needs connectivity, licensing, and a server behind it.

This is the opposite bet: bake the ground truth once, ship it inside a single file, and let it run anywhere — a planning laptop, a kiosk, a briefing screen with no network at all. The engine started as an aircraft showcase; pointing it at Hohenfels showed the same offline-first approach scales straight from one airfield to a whole maneuver box.