Updated builds.

build/three.js

@@ -26495,6 +26495,8 @@
 
 	function InterleavedBufferAttribute( interleavedBuffer, itemSize, offset, normalized ) {
 
+		this.name = '';
+
 		this.data = interleavedBuffer;
 		this.itemSize = itemSize;
 		this.offset = offset;
@@ -26639,6 +26641,57 @@
 
 			return this;
 
+		},
+
+		clone: function () {
+
+			console.log( 'THREE.InterleavedBufferAttribute.clone(): Cloning an interlaved buffer attribute will deinterleave buffer data.' );
+
+			var array = [];
+
+			for ( var i = 0; i < this.count; i ++ ) {
+
+				var index = i * this.data.stride + this.offset;
+
+				for ( var j = 0; j < this.itemSize; j ++ ) {
+
+					array.push( this.data.array[ index + j ] );
+
+				}
+
+			}
+
+			return new BufferAttribute( new this.array.constructor( array ), this.itemSize, this.normalized );
+
+		},
+
+		toJSON: function () {
+
+			console.log( 'THREE.InterleavedBufferAttribute.toJSON(): Serializing an interlaved buffer attribute will deinterleave buffer data.' );
+
+			var array = [];
+
+			for ( var i = 0; i < this.count; i ++ ) {
+
+				var index = i * this.data.stride + this.offset;
+
+				for ( var j = 0; j < this.itemSize; j ++ ) {
+
+					array.push( this.data.array[ index + j ] );
+
+				}
+
+			}
+
+			// deinterleave data and save it as an ordinary buffer attribute for now
+
+			return {
+				itemSize: this.itemSize,
+				type: this.array.constructor.name,
+				array: array,
+				normalized: this.normalized
+			};
+
 		}
 
 	} );

build/three.module.js

@@ -26487,6 +26487,8 @@ var _vector$6 = new Vector3();
 
 function InterleavedBufferAttribute( interleavedBuffer, itemSize, offset, normalized ) {
 
+	this.name = '';
+
 	this.data = interleavedBuffer;
 	this.itemSize = itemSize;
 	this.offset = offset;
@@ -26631,6 +26633,57 @@ Object.assign( InterleavedBufferAttribute.prototype, {
 
 		return this;
 
+	},
+
+	clone: function () {
+
+		console.log( 'THREE.InterleavedBufferAttribute.clone(): Cloning an interlaved buffer attribute will deinterleave buffer data.' );
+
+		var array = [];
+
+		for ( var i = 0; i < this.count; i ++ ) {
+
+			var index = i * this.data.stride + this.offset;
+
+			for ( var j = 0; j < this.itemSize; j ++ ) {
+
+				array.push( this.data.array[ index + j ] );
+
+			}
+
+		}
+
+		return new BufferAttribute( new this.array.constructor( array ), this.itemSize, this.normalized );
+
+	},
+
+	toJSON: function () {
+
+		console.log( 'THREE.InterleavedBufferAttribute.toJSON(): Serializing an interlaved buffer attribute will deinterleave buffer data.' );
+
+		var array = [];
+
+		for ( var i = 0; i < this.count; i ++ ) {
+
+			var index = i * this.data.stride + this.offset;
+
+			for ( var j = 0; j < this.itemSize; j ++ ) {
+
+				array.push( this.data.array[ index + j ] );
+
+			}
+
+		}
+
+		// deinterleave data and save it as an ordinary buffer attribute for now
+
+		return {
+			itemSize: this.itemSize,
+			type: this.array.constructor.name,
+			array: array,
+			normalized: this.normalized
+		};
+
 	}
 
 } );