import { BaseViewerType } from '../../viewers/_Base';
import { PolyScene } from '../../scene/PolyScene';
export declare class ViewersRegister {
    protected scene: PolyScene;
    private _viewers_by_id;
    constructor(scene: PolyScene);
    registerViewer(viewer: BaseViewerType): void;
    unregisterViewer(viewer: BaseViewerType): void;
    traverseViewers(callback: (viewer: BaseViewerType) => void): void;
}