Terrain skyline 地形天際線 3D panorama

The 360° skyline around any coordinate, from real elevation data — then the white-tiger check (白虎抬头, Δ > 10°) computed by the same kernel as our API. Drag the panorama to look around; change the sitting direction and the verdict re-runs in your browser.

How it works

• Sampling: 360 azimuths × 2 distances (700 m, 2500 m) via opentopodata / SRTM 30 m; skyline elevation angle = max_d atan2(h − h₀, d). Results are cached per ~1 km grid cell.
• Verdict: right sector = sitting + 90° ± 45° (white tiger), left = sitting − 90° ± 45° (blue dragon). Δ = right_max − left_max; Δ > 10° ⇒ 白虎抬头. The threshold is an estimate from 04 §3.3 awaiting advisor calibration — it is printed with the verdict, not hidden.
• Same kernel: terrain_white_tiger_json is the identical WASM function served by the public API (POST /v1/bridge/terrain_white_tiger) and MCP tool terrain_white_tiger.

Honest boundaries

• DTM, not DSM: elevation models exclude buildings — mountain/skyline form is in scope; urban 天斩煞 / gap effects need a DSM and are not computed here.
• No orientation from photos or satellites: the sitting direction is your input (measure it with a compass or solar compass); the page never infers it.
• Cultural and educational use only — a geometric marker, not a prediction.