Updated builds.

build/three.js

@@ -9264,6 +9264,7 @@
 	 */
 
 	var _vector$3 = new Vector3();
+	var _vector2$1 = new Vector2();
 
 	function BufferAttribute( array, itemSize, normalized ) {
 
@@ -9454,15 +9455,27 @@
 
 		applyMatrix3: function ( m ) {
 
-			for ( var i = 0, l = this.count; i < l; i ++ ) {
+			if ( this.itemSize === 2 ) {
 
-				_vector$3.x = this.getX( i );
-				_vector$3.y = this.getY( i );
-				_vector$3.z = this.getZ( i );
+				for ( var i = 0, l = this.count; i < l; i ++ ) {
 
-				_vector$3.applyMatrix3( m );
+					_vector2$1.fromBufferAttribute( this, i );
+					_vector2$1.applyMatrix3( m );
 
-				this.setXYZ( i, _vector$3.x, _vector$3.y, _vector$3.z );
+					this.setXY( i, _vector2$1.x, _vector2$1.y );
+
+				}
+
+			} else if ( this.itemSize === 3 ) {
+
+				for ( var i$1 = 0, l$1 = this.count; i$1 < l$1; i$1 ++ ) {
+
+					_vector$3.fromBufferAttribute( this, i$1 );
+					_vector$3.applyMatrix3( m );
+
+					this.setXYZ( i$1, _vector$3.x, _vector$3.y, _vector$3.z );
+
+				}
 
 			}
 

build/three.module.js

@@ -9258,6 +9258,7 @@ MeshBasicMaterial.prototype.copy = function ( source ) {
  */
 
 const _vector$3 = new Vector3();
+const _vector2$1 = new Vector2();
 
 function BufferAttribute( array, itemSize, normalized ) {
 
@@ -9448,15 +9449,27 @@ Object.assign( BufferAttribute.prototype, {
 
 	applyMatrix3: function ( m ) {
 
-		for ( let i = 0, l = this.count; i < l; i ++ ) {
+		if ( this.itemSize === 2 ) {
 
-			_vector$3.x = this.getX( i );
-			_vector$3.y = this.getY( i );
-			_vector$3.z = this.getZ( i );
+			for ( let i = 0, l = this.count; i < l; i ++ ) {
 
-			_vector$3.applyMatrix3( m );
+				_vector2$1.fromBufferAttribute( this, i );
+				_vector2$1.applyMatrix3( m );
 
-			this.setXYZ( i, _vector$3.x, _vector$3.y, _vector$3.z );
+				this.setXY( i, _vector2$1.x, _vector2$1.y, );
+
+			}
+
+		} else if ( this.itemSize === 3 ) {
+
+			for ( let i = 0, l = this.count; i < l; i ++ ) {
+
+				_vector$3.fromBufferAttribute( this, i );
+				_vector$3.applyMatrix3( m );
+
+				this.setXYZ( i, _vector$3.x, _vector$3.y, _vector$3.z );
+
+			}
 
 		}