diff --git a/types/three/three-mtlloader.d.ts b/types/three/three-mtlloader.d.ts
index 33b4822432..c2dbd40c84 100644
--- a/types/three/three-mtlloader.d.ts
+++ b/types/three/three-mtlloader.d.ts
@@ -3,16 +3,48 @@
 
 import { Material } from "./three-core";
 import {LoadingManager} from "./three-core";
+import {Mapping} from "./three-core";
 import {EventDispatcher} from "./three-core";
 import {BufferGeometry} from "./three-core";
+import {Side} from "./three-core";
 import {Texture} from "./three-core";
+import {Vector2} from "./three-core";
+import {Wrapping} from "./three-core";
+
+export interface MaterialCreatorOptions {
+    /**
+     * side: Which side to apply the material
+     * THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
+     */
+    side?: Side;
+    /*
+     * wrap: What type of wrapping to apply for textures
+     * THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
+     */
+    wrap?: Wrapping;
+    /*
+     * normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
+     * Default: false, assumed to be already normalized
+     */
+    normalizeRGB?: boolean;
+    /*
+     * ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
+     * Default: false
+     */
+    ignoreZeroRGBs?: boolean;
+    /*
+     * invertTrProperty: Use values 1 of Tr field for fully opaque. This option is useful for obj
+     * exported from 3ds MAX, vcglib or meshlab.
+     * Default: false
+     */
+    invertTrProperty?: boolean;
+}
 
 export class MTLLoader extends EventDispatcher {
 
     constructor(manager?: LoadingManager);
     manager: LoadingManager;
-    materialOptions: {};
-    materials: Material[];
+    materialOptions: MaterialCreatorOptions;
     path: string;
     texturePath: string;
     crossOrigin: boolean;
@@ -23,32 +55,54 @@ export class MTLLoader extends EventDispatcher {
     setTexturePath(path: string) : void;
     setBaseUrl(path: string) : void;
     setCrossOrigin(value: boolean) : void;
-    setMaterialOptions(value: any) : void;
+    setMaterialOptions(value: MaterialCreatorOptions) : void;
+}
+
+export interface MaterialInfo {
+    ks?: number[];
+    kd?: number[];
+    ke?: number[];
+    map_kd?: string;
+    map_ks?: string;
+    map_ke?: string;
+    norm?: string;
+    map_bump?: string;
+    bump?: string;
+    map_d?: string;
+    ns?: number;
+    d?: number;
+    tr?: number;
+}
+
+export interface TexParams {
+    scale: Vector2;
+    offset: Vector2;
+    url: string;
 }
 
 export class MaterialCreator {
 
-    constructor(baseUrl?: string, options?: any);
+    constructor(baseUrl?: string, options?: MaterialCreatorOptions);
 
     baseUrl : string;
-    options : any;
-    materialsInfo : any;
-    materials : any;
-    materialsArray : Material[];
-    nameLookup : any;
-    side : number;
-    wrap : number;
+    options : MaterialCreatorOptions;
+    materialsInfo : {[key: string]: MaterialInfo};
+    materials : {[key: string]: Material};
+    private materialsArray : Material[];
+    nameLookup : {[key: string]: number};
+    side : Side;
+    wrap : Wrapping;
 
     setCrossOrigin( value: boolean ) : void;
-    setManager( value: any ) : void;
-    setMaterials( materialsInfo: any ) : void;
-    convert( materialsInfo: any ) : any;
+    setManager( value: LoadingManager ) : void;
+    setMaterials( materialsInfo: {[key: string]: MaterialInfo} ) : void;
+    convert( materialsInfo: {[key: string]: MaterialInfo} ) : {[key: string]: MaterialInfo};
     preload() : void;
     getIndex( materialName: string ) : Material;
     getAsArray() : Material[];
     create( materialName: string ) : Material;
     createMaterial_( materialName: string ) : Material;
-    getTextureParams( value: string, matParams: any ) : any;
-    loadTexture(url: string, mapping: any, onLoad: (bufferGeometry: BufferGeometry) => void, onProgress?: (event: ProgressEvent) => void, onError?: (event: ErrorEvent) => void): Texture;
+    getTextureParams( value: string, matParams: any ) : TexParams;
+    loadTexture(url: string, mapping?: Mapping, onLoad?: (bufferGeometry: BufferGeometry) => void, onProgress?: (event: ProgressEvent) => void, onError?: (event: ErrorEvent) => void): Texture;
 
 }