Merge pull request #15989 from Methuselah96/typescript-utils

Add TypeScript definitions for some utils

examples/jsm/utils/BufferGeometryUtils.d.ts

+import { BufferAttribute, BufferGeometry } from '../../../src/Three';
+
+export namespace BufferGeometryUtils {
+    export function mergeBufferGeometries(geometries: BufferGeometry[]): BufferGeometry;
+    export function computeTangents(geometry: BufferGeometry): null;
+    export function mergeBufferAttributes(attributes: BufferAttribute[]): BufferAttribute;
+}

examples/jsm/utils/GeometryUtils.d.ts

+/**
+ * @deprecated
+ */
+export namespace GeometryUtils {
+    /**
+     * @deprecated Use {@link Geometry#merge geometry.merge( geometry2, matrix, materialIndexOffset )} instead.
+     */
+    export function merge(geometry1: any, geometry2: any, materialIndexOffset?: any): any;
+    /**
+     * @deprecated Use {@link Geometry#center geometry.center()} instead.
+     */
+    export function center(geometry: any): any;
+}

examples/jsm/utils/SceneUtils.d.ts

+import { Geometry, Material, Object3D, Scene } from '../../../src/Three';
+
+export namespace SceneUtils {
+    export function createMultiMaterialObject(geometry: Geometry, materials: Material[]): Object3D;
+    export function detach(child: Object3D, parent: Object3D, scene: Scene): void;
+    export function attach(child: Object3D, scene: Scene, parent: Object3D): void;
+}