Update app.py

app.py

@@ -703,7 +703,7 @@ async(c, o, p, d, n, m, s)=>{
         window.ctx = null;
         window.video = document.getElementById("depth_video").getElementsByTagName("video")[0];
         window.parallax = 0;
-        window.xdir = new BABYLON.Vector3(-1, 0, 0);
+        window.xdir = new BABYLON.Vector3(-1, -1, -1);
         window.rdir = new BABYLON.Vector3(0, 0, 0);
 
         document.getElementById("model3D").getElementsByTagName("canvas")[0].addEventListener('pointermove', function(evt) {