/**
 * `grass_field` studio: a GPU grass patch authored as a box volume — its XZ footprint is the grass
 * area, its top the ground height. Pure config here (blade/wind/color params + a footprint resolver);
 * the instanced vertex-wind grass mesh lives in the `shell` renderer, which drives the existing
 * `GrassField`. An engine environment kind (like water/scatter) so grass wind and colours are
 * slider-authorable in the editor and persisted in `editor.scene.json` — the #813 grass studio.
 *
 * @capability grass-field editor-authorable GPU grass patch
 */
import { type ParamSchema, type SceneKindObject } from "../scene/sceneKinds.js";
/** The editor volume kind marking a box as a GPU grass patch. */
export declare const GRASS_FIELD_KIND = "grass_field";
/** Fully-defaulted grass params parsed from a volume's `meta`. */
export interface GrassRules {
    /** Blades per square meter (the shell caps by an instance budget). */
    density: number;
    /** Blade height in meters. */
    bladeHeight: number;
    /** Blade-width range in metres; endpoints are normalized on read. */
    bladeWidthMin: number;
    bladeWidthMax: number;
    /** Bend range, 0..1. */
    bladeBendMin: number;
    bladeBendMax: number;
    /** Spread of blades around each tuft root, in metres. */
    tuftRadius: number;
    /** Normal lift toward the sky, 0..1; controls the card lighting response. */
    normalLift: number;
    /** Base (root) color, hex. */
    colorBase: string;
    /** Tip color, hex. */
    colorTip: string;
    /** Per-blade color jitter, 0..1. */
    colorVariation: number;
    /** Vertex-wind sway strength, 0..1. */
    windStrength: number;
    /** Wind animation speed. */
    windSpeed: number;
    /** Gust patch scale (spatial frequency of gusts). */
    windGust: number;
    /** Blade material roughness, 0..1. */
    roughness: number;
    /**
     * Ground-cover mat strength, 0..1: the patch paints a turf surface over its footprint instead of
     * leaving the ground beneath the blades bare. 0 keeps blades only.
     */
    groundCover: number;
    /** Seed string; same seed reproduces the same blade layout. */
    seed: string;
}
/** Grass defaults: a lush, lightly-swaying meadow. */
export declare const GRASS_DEFAULTS: GrassRules;
/** The grass parameter schema — drives the inspector and `meta` parse via the studio seam. */
export declare const GRASS_SCHEMA: ParamSchema;
/** Parse a volume's `meta` into fully-defaulted grass rules. @internal */
export declare function readGrassRules(meta: Record<string, unknown> | undefined): GrassRules;
/** A resolved grass patch: world-space area center at ground height, footprint size (XZ), and rules. */
export interface ResolvedGrass {
    center: readonly [number, number, number];
    size: readonly [number, number];
    rules: GrassRules;
}
/** Resolve a grass volume into an area footprint (from box half-extents / radius) at the box base. @internal */
export declare function resolveGrassObject(object: SceneKindObject): ResolvedGrass | null;
/** Registers the `grass_field` scene kind (schema + resolver). Called by {@link registerBuiltinSceneKinds}. @internal */
export declare function registerGrassKind(): void;