Prepare Mountain Terrain imports a fixed public USGS elevation set covering Palisades and Alpine. It creates a 20-meter regional heightfield, a 1-meter Siberia ridge crop with a 350-meter scenery margin, and a route descriptor.

Use the node Run button or the workflow run API. Both dispatch preparation to the durable worker. Preparation runs on bounded GDAL compute and charges no user credits. It requires an explicit run. Game playback and downstream manifest refresh reuse the cached results.

The optional preset text input or config accepts palisades-alpine-siberia-v1. Other values are refused. Arbitrary source URLs and shell commands are not accepted.

Wire terrain_coarse, terrain_detail and terrain_route into matching Game input ports. Each output is a URL with type: "data"; the game receives its bytes through wf.onAssetData. No terrain network access is granted to the game frame.

The course uses the approximately 502-meter OpenStreetMap Siberia ridge slice ending at the Mainline junction. It is a geographic reference, with approximate winter corridor and resort naming. Source elevations describe bare earth, not snow depth. The route carries USGS provenance, input SHA256 values and OpenStreetMap attribution.

Outputs are immutable and content-addressed. Source ETags, byte sizes, coordinates and the processor version determine their identity. A manifest becomes available only after every asset upload succeeds. Retrying a completed preparation recovers that manifest.