import { Nullable } from "@babylonjs/core/types";
import { Observable } from "@babylonjs/core/Misc/observable";
import { Material } from "@babylonjs/core/Materials/material";
import { TransformNode } from "@babylonjs/core/Meshes/transformNode";
import { Mesh } from "@babylonjs/core/Meshes/mesh";
import { INode, IMaterial } from "../glTFLoaderInterfaces";
import { IGLTFLoaderExtension } from "../glTFLoaderExtension";
import { GLTFLoader } from "../glTFLoader";
import { IProperty } from 'babylonjs-gltf2interface';
/**
 * [Specification](https://github.com/KhronosGroup/glTF/tree/master/extensions/2.0/Vendor/MSFT_lod)
 */
export declare class MSFT_lod implements IGLTFLoaderExtension {
    /** The name of this extension. */
    readonly name = "MSFT_lod";
    /** Defines whether this extension is enabled. */
    enabled: boolean;
    /**
     * Maximum number of LODs to load, starting from the lowest LOD.
     */
    maxLODsToLoad: number;
    /**
     * Observable raised when all node LODs of one level are loaded.
     * The event data is the index of the loaded LOD starting from zero.
     * Dispose the loader to cancel the loading of the next level of LODs.
     */
    onNodeLODsLoadedObservable: Observable<number>;
    /**
     * Observable raised when all material LODs of one level are loaded.
     * The event data is the index of the loaded LOD starting from zero.
     * Dispose the loader to cancel the loading of the next level of LODs.
     */
    onMaterialLODsLoadedObservable: Observable<number>;
    private _loader;
    private _nodeIndexLOD;
    private _nodeSignalLODs;
    private _nodePromiseLODs;
    private _materialIndexLOD;
    private _materialSignalLODs;
    private _materialPromiseLODs;
    /** @hidden */
    constructor(loader: GLTFLoader);
    /** @hidden */
    dispose(): void;
    /** @hidden */
    onReady(): void;
    /** @hidden */
    loadNodeAsync(context: string, node: INode, assign: (babylonTransformNode: TransformNode) => void): Nullable<Promise<TransformNode>>;
    /** @hidden */
    _loadMaterialAsync(context: string, material: IMaterial, babylonMesh: Mesh, babylonDrawMode: number, assign: (babylonMaterial: Material) => void): Nullable<Promise<Material>>;
    /** @hidden */
    _loadUriAsync(context: string, property: IProperty, uri: string): Nullable<Promise<ArrayBufferView>>;
    /**
     * Gets an array of LOD properties from lowest to highest.
     */
    private _getLODs;
    private _disposeUnusedMaterials;
}