Fixed a normalization issue for the PlayBook platform.

src/renderers/WebGLShaders.js

@@ -1283,7 +1283,7 @@ THREE.ShaderLib = {
 			"void main() {",
 
 				"vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );",
-				"vNormal = normalize( normalMatrix * normal );",
+				"vNormal = normalMatrix * normal;",
 
 				"gl_Position = projectionMatrix * mvPosition;",