import { ContextManager, Observable, ConstructorProps } from '@zcomponent/core';
import { Group } from '../Group';
declare enum BillboardMode {
    LookAt = "Look-At",
    YBillboard = "Y-Billboard"
}
/**
 * Billboard acts in the same way as Group except that each frame it rotates so that it faces the camera.
 *
 * Root element: [THREE.Group](https://threejs.org/docs/index.html?q=Grou#api/en/objects/Group)
 *
 * @zcomponent
 * @ztag three/Object3D/Group/Billboard
 * @zparents three/Object3D/Group/**
 * @zgroup Transforms
 * @zicon transform
 */
export declare class Billboard extends Group {
    /**
     * Creates a Billboard component.
     * @param mgr - The context manager.
     * @param props - The constructor properties.
     */
    constructor(mgr: ContextManager, props: ConstructorProps);
    private _update;
    private onPropChange;
    /**
     * The axis to lock the billboard to.
     * @zprop
     * @zdefault Y-Billboard
     * @zgroup Billboard
     * @zgrouppriority 20
     */
    lock: Observable<BillboardMode, never>;
    /**
     * Whether the billboard is enabled.
     * @zprop
     * @zdefault true
     * @zgroup Billboard
     * @zgrouppriority 21
     */
    enabled: Observable<boolean, never>;
}
export {};