/** One placed transform along a path: grounded position, facing yaw, and its ordinal + arc distance. */
export interface PathInstance {
    index: number;
    /** Arc-length distance from the path start, meters. */
    distance: number;
    position: readonly [number, number, number];
    /** Yaw (radians) facing along the direction of travel. */
    yaw: number;
}
/** Options for {@link placeAlongPath}. */
export interface PlaceAlongPathOptions {
    /** Target meters between instances. The run is divided into equal spans nearest this spacing. */
    spacing: number;
    /** Ground each instance to this height sampler (else y = 0). */
    sampleHeight?: (x: number, z: number) => number;
    /** Force at least this many instances regardless of length. Default 1 (endpoints only when short). */
    minCount?: number;
}
/**
 * Evenly place transforms along `points` (XZ polyline). The run length is divided into the whole
 * number of equal spans closest to `spacing`, so instances always land on both endpoints and stay
 * evenly distributed. Returns `spans + 1` instances. Empty for fewer than 2 points.
 */
export declare function placeAlongPath(points: readonly {
    x: number;
    z: number;
}[], options: PlaceAlongPathOptions): PathInstance[];