Type Alias: SurfaceLook

type SurfaceLook = "terrain" | "bands" | "metallic";

Visual archetype for planetary bodies — drives the shader family + palette generator + atmosphere defaults. Independent from the body's physical type (a planet can read as 'metallic' regardless of its mass / composition; the caller picks the look that matches its game state).

• 'terrain' : rocky-like — low/high colour ramp, translucent atmo halo by default. Suits Earth-like, lunar, lava worlds, etc.
• 'bands' : gas-like — 4-stop band palette, opaque atmo by default (smooth sphere acts as the atmospheric silhouette).
• 'metallic' : 4-band metallic palette with a metalness sheen, no atmo halo by default.

Defaults to 'terrain' when omitted on a planetary BodyConfig. Stars ignore this field (their pipeline is fixed).