Fallback levels

Level 0   3D Tiles + Arrow style + shader color
Level 1   3D Tiles original material (no style)
Level 2   PMTiles footprint extrusion with style color
Level 3   PMTiles flat plates
off       render nothing

Set the policy on <Plateau fallback="...">:

policy	behavior
'auto' (default)	pick the highest-quality level the data supports
'force-3dtiles'	prefer 3D Tiles; degrades 0 → 1 if feature ids missing
'force-footprint'	always render PMTiles fallback
'off'	render nothing

The runtime resolves to a concrete FallbackMode automatically. Mount <FallbackExtrusionLayer> inside <Plateau> to have the PMTiles path auto-mount when the mode is level-2-pmtiles-extruded or level-3-pmtiles-flat.

import { Plateau, FallbackExtrusionLayer } from '@yodolabs/plateau-r3f';

<Plateau city="..." fallback="auto">
  <FallbackExtrusionLayer />
</Plateau>

Triggers

The runtime drops to a lower level when:

• manifest.artifacts.tiles_available === false
• manifest.artifacts.style_available === false
• any tile geometry has no _FEATURE_ID_0 / _BATCHID attribute
• a style/*.arrow request fails

You're notified via onError; the lifecycle state for that tile becomes featureIdMissing.