Updated builds.

build/three.js

@@ -45229,6 +45229,13 @@
 
 	function GridHelper( size, divisions, color1, color2 ) {
 
+		this.parameters = {
+			size: size,
+			divisions: divisions,
+			color1: color1,
+			color2: color2
+		};
+
 		size = size || 10;
 		divisions = divisions || 10;
 		color1 = new Color( color1 !== undefined ? color1 : 0x444444 );
@@ -45264,8 +45271,29 @@
 
 	}
 
-	GridHelper.prototype = Object.create( LineSegments.prototype );
-	GridHelper.prototype.constructor = GridHelper;
+	GridHelper.prototype = Object.assign( Object.create( LineSegments.prototype ), {
+
+		constructor: GridHelper,
+
+		copy: function ( source ) {
+
+			LineSegments.prototype.copy.call( this, source );
+
+			Object.assign( this.parameters, source.parameters );
+
+			return this;
+
+		},
+
+		clone: function () {
+
+			var parameters = this.parameters;
+
+			return new this.constructor( parameters.size, parameters.divisions, parameters.color1, parameters.color2 );
+
+		}
+
+	} );
 
 	/**
 	 * @author mrdoob / http://mrdoob.com/

build/three.module.js

@@ -45223,6 +45223,13 @@ HemisphereLightHelper.prototype.update = function () {
 
 function GridHelper( size, divisions, color1, color2 ) {
 
+	this.parameters = {
+		size: size,
+		divisions: divisions,
+		color1: color1,
+		color2: color2
+	};
+
 	size = size || 10;
 	divisions = divisions || 10;
 	color1 = new Color( color1 !== undefined ? color1 : 0x444444 );
@@ -45258,8 +45265,29 @@ function GridHelper( size, divisions, color1, color2 ) {
 
 }
 
-GridHelper.prototype = Object.create( LineSegments.prototype );
-GridHelper.prototype.constructor = GridHelper;
+GridHelper.prototype = Object.assign( Object.create( LineSegments.prototype ), {
+
+	constructor: GridHelper,
+
+	copy: function ( source ) {
+
+		LineSegments.prototype.copy.call( this, source );
+
+		Object.assign( this.parameters, source.parameters );
+
+		return this;
+
+	},
+
+	clone: function () {
+
+		var parameters = this.parameters;
+
+		return new this.constructor( parameters.size, parameters.divisions, parameters.color1, parameters.color2 );
+
+	}
+
+} );
 
 /**
  * @author mrdoob / http://mrdoob.com/