diff --git a/scripts/demo.js b/scripts/demo.js
index 56b3504..c444dd4 100644
--- a/scripts/demo.js
+++ b/scripts/demo.js
@@ -3,20 +3,20 @@
 function runDemo(canvasId) {
 	var canvas = document.getElementById(canvasId);
 	var engine = new BABYLON.Engine(canvas, true);
-	
+
 	// Cr�ation de la sc�ne
 	var scene = new BABYLON.Scene(engine);
     scene.gravity = new BABYLON.Vector3(0, -9.81, 0);
 	scene.collisionsEnabled = true;
-    
+
 	// Ajout d'une cam�ra et de son contr�leur
     var camera = new BABYLON.FreeCamera("MainCamera", new BABYLON.Vector3(0, 2.5, 5), scene);
     camera.applyGravity = true;
     camera.checkCollisions = true;
-	
+
 	camera.speed = 0.5;
 	camera.angularSensibility = 1000;
-	
+
 	camera.keysUp = [90]; // Touche Z
 	camera.keysDown = [83]; // Touche S
 	camera.keysLeft = [81]; // Touche Q
@@ -28,19 +28,19 @@ function runDemo(canvasId) {
 	}else if(camera.position.x<-2){
 		camera.position.x=-2;
 	}
-	
+
 	// Ajout d'une lumi�re
 	var light = new BABYLON.PointLight("DirLight", new BABYLON.Vector3(0, 10, 0), scene);
 	light.diffuse = new BABYLON.Color3(1, 1, 1);
 	light.specular = new BABYLON.Color3(0.6, 0.6, 0.6);
 	light.intensity = 1.5;
-	
+
 	// On ajoute une skybox
 	createSkybox(scene);
-	
+
 	// Enfin la sc�ne de d�mo
 	createDemoScene(scene);
-	
+
 	// Lancement de la boucle principale
 	engine.runRenderLoop(function() {
 		scene.render();
@@ -53,7 +53,7 @@ function createSkybox(scene) {
 	sMaterial.backFaceCulling = false;
 	sMaterial.reflectionTexture = new BABYLON.CubeTexture("images/skybox/skybox", scene);
 	sMaterial.reflectionTexture.coordinatesMode = BABYLON.Texture.SKYBOX_MODE;
-	
+
 	// Cr�ation d'un cube avec la material adapt�e
 	var skybox = BABYLON.Mesh.CreateBox("skybox", 250, scene);
 	skybox.material = sMaterial;
@@ -71,41 +71,45 @@ function createDemoScene(scene) {
 	mur1.rotation.y = Math.PI / 2;
 	mur1.position.y = 20;
 	mur1.position.x = 25;
+	mur1.visibility = 0;
 	mur1.checkCollisions = true;
 
 	var mur2 = BABYLON.Mesh.CreatePlane("mur2", 50, scene);
 	mur2.rotation.y = -(Math.PI / 2);
 	mur2.position.y = 20;
 	mur2.position.x = -25;
+	mur2.visibility = 0;
 	mur2.checkCollisions = true;
 
 	var mur3 = BABYLON.Mesh.CreatePlane("mur3", 50, scene);
 	mur3.rotation.z = Math.PI / 2;
 	mur3.position.z = 25;
+	mur3.visibility = 0;
 	mur3.checkCollisions = true;
 
 	var mur4 = BABYLON.Mesh.CreatePlane("mur4", 50, scene);
 	mur4.rotation.x = Math.PI;
 	mur4.position.z = -25;
+	mur4.visibility = 0;
 	mur4.checkCollisions = true;
-	
+
 	// Et quelques cubes...
 	var boxMaterial = new BABYLON.StandardMaterial("bMaterial", scene);
 	boxMaterial.diffuseTexture = new BABYLON.Texture("images/box.png", scene);
-	
+
 	var positions = [
 		{ x: -15, z: 15 },
 		{ x: -15, z: -15 },
 		{ x: 15, z: 15 },
 		{ x: 15, z: -15 }
 	];
-	
+
 	var cubeSize = 2.5;
-	
+
 	for (var i = 0; i < 4; i++) {
 		var box = BABYLON.Mesh.CreateBox("box1", cubeSize, scene);
 		box.position = new BABYLON.Vector3(positions[i].x, cubeSize / 2, positions[i].z);
 		box.material = boxMaterial;
 		box.checkCollisions = true;
 	}
-}
\ No newline at end of file
+}