Logs / Route 003
Hachijō-jima at 1:1
How a Japanese elevation survey, OpenStreetMap and a lot of aerial photos turn into a drivable island. Also, the case of the harbour that had no quays.
Hachijō-jima is a real place. About 7,000 people live there, it has an airport, a handful of harbours and two volcanoes, and it sits in the Izu island chain about 290 km south of Tokyo. In Sandbox Drive it’s the whole map, and a kilometre in the game is a kilometre on the island.
None of the terrain is sculpted by hand. The real island is more interesting than anything anyone would invent, and it comes with roads that already make sense.
Starting from measurements
The ground comes from the elevation data published by Japan’s Geospatial Information Authority. The roads start from OpenStreetMap. That gives:
| World | 19.1 × 14.8 km |
| Land | 73.4 km² |
| Hachijō-Fuji | 854 m |
| Mihara | 701 m |
| Real roads | 166 km |
| Roads in the game | 233 km |
Most of that difference, about 64 km, is new road. The real road map is built for the people who live there, not for a lorry trying to reach a forest log landing, so the game adds farm lanes, site access roads and quay roads on top. Everything real stays.
The ground is a surface, not a picture
This one took a while to get right. The colour of the ground isn’t just decoration: it’s the surface the tyres are standing on. Asphalt, gravel, firm grass, loose volcanic scoria, mud. The physics reads it, so painting the ground is really setting the grip for the whole island.
That changes how it has to be painted. The first pass covered about 90% of the island in forest-floor litter. It looked like one enormous dirt patch, and any road car that slipped off the tarmac got stuck on the spot. Looking good and driving well turned out to pull in the same direction: the green is where a car can go. Now roughly two thirds of the land is firm, about 15% is soft, and the mud and loose scoria are there on purpose, for the vehicles built for them.
On top of the ground grows grass, drawn blade by blade on the graphics card, with the species picked by the ground it grows on. The local ones are in there, including ashitaba, which the island is famous for, and freesia, which it holds a festival for every spring.
Work sites, traced from the real ones
The economy needs places to load and unload: a fish landing, a quarry, a dairy, a sawmill, a flower farm. There are 46 sites planned so far. Wherever the real island has a matching facility within about a kilometre, the site is laid out from the real one, using aerial photos and map data. Where it doesn’t, a template based on a real Japanese example gets fitted onto the terrain.
Every site gets a sheet so it can be checked before it’s built. On the left, the plan drawn over the aerial photo. On the right, a bird’s-eye render of the game terrain with every building, loading bay and access ramp tagged. This is Kaminato, a port on the north coast:
The harbour that had no quays
The best bug from building the island, because nothing was technically wrong.
The elevation data masks out water. Sensible, until it turns out that to the dataset, a concrete quay built out into the sea counts as sea. So several harbours in the terrain simply had no quays. The aerial photo showed a pier, and the game showed open water where the pier should be.
The fix is a deck: a flat raised area put back where the quay should be, levelled to match its neighbours. The site tools now check every site for quays the terrain doesn’t have, so the next one gets caught before it’s built.
And the volcano
Hachijō-Fuji hasn’t erupted in over four hundred years. In the game it has a bit more going on: a lava lake in the crater with a cooling crust around its edge, steam vents on the rim, and a plume you can see from anywhere on the island, bent by the same wind that drives the weather. For now it’s scenery.
The site plans exist, but they’re not in the world yet. Placing them, with their buildings, markers and loading bays, comes next, along with the trailers the jobs need.
Elevation data and aerial imagery: Geospatial Information Authority of Japan (GSI), Public Data License 1.0. Map data © OpenStreetMap contributors, available under the Open Database License (ODbL).
Filed under hachijo-jima, world, behind-the-scenes