Vector3.unproject(): Avoid computing inverse

Author: WestLangley

src/math/Vector3.js

@@ -1,5 +1,4 @@
 import { _Math } from './Math.js';
-import { Matrix4 } from './Matrix4.js';
 import { Quaternion } from './Quaternion.js';
 
 /**
@@ -320,15 +319,9 @@ Object.assign( Vector3.prototype, {
 
 	unproject: function () {
 
-		var matrix = new Matrix4();
+		return this.applyMatrix4( camera.projectionMatrixInverse ).applyMatrix4( camera.matrixWorld );
 
-		return function unproject( camera ) {
-
-			return this.applyMatrix4( matrix.getInverse( camera.projectionMatrix ) ).applyMatrix4( camera.matrixWorld );
-
-		};
-
-	}(),
+	},
 
 	transformDirection: function ( m ) {