Updated builds.

build/three.js

@@ -16508,15 +16508,15 @@
 		};
 	}
 
-	function ArrayCamera(array = []) {
-		PerspectiveCamera.call(this);
-		this.cameras = array;
+	class ArrayCamera extends PerspectiveCamera {
+		constructor(array = []) {
+			super();
+			this.cameras = array;
+		}
+
 	}
 
-	ArrayCamera.prototype = Object.assign(Object.create(PerspectiveCamera.prototype), {
-		constructor: ArrayCamera,
-		isArrayCamera: true
-	});
+	ArrayCamera.prototype.isArrayCamera = true;
 
 	class Group extends Object3D {
 		constructor() {

build/three.module.js

@@ -21559,21 +21559,19 @@ function WebGLUtils( gl, extensions, capabilities ) {
 
 }
 
-function ArrayCamera( array = [] ) {
+class ArrayCamera extends PerspectiveCamera {
 
-	PerspectiveCamera.call( this );
+	constructor( array = [] ) {
 
-	this.cameras = array;
-
-}
+		super();
 
-ArrayCamera.prototype = Object.assign( Object.create( PerspectiveCamera.prototype ), {
+		this.cameras = array;
 
-	constructor: ArrayCamera,
+	}
 
-	isArrayCamera: true
+}
 
-} );
+ArrayCamera.prototype.isArrayCamera = true;
 
 class Group extends Object3D {