export interface AtlasPlacement {
    offset: [number, number, number];
}
export interface AtlasLayout {
    /** Dimensions of the 3D atlas texture. */
    size: [number, number, number];
    /** One placement per input size, in input order. */
    placements: AtlasPlacement[];
}
/**
 * Packs model boxes into a single 3D atlas using a shelf algorithm:
 * boxes fill a row along x, rows stack along y into a layer, layers
 * stack along z. Placements are returned in input order so they can be
 * indexed by model index.
 */
export declare function packAtlas(sizes: [number, number, number][], maxSize: number): AtlasLayout;
