MeshStandardMaterial: Changed roughness and metalness default values.

src/materials/MeshStandardMaterial.js

@@ -64,8 +64,8 @@ function MeshStandardMaterial( parameters ) {
 	this.type = 'MeshStandardMaterial';
 
 	this.color = new Color( 0xffffff ); // diffuse
-	this.roughness = 0.5;
-	this.metalness = 0.5;
+	this.roughness = 1.0;
+	this.metalness = 0.0;
 
 	this.map = null;