Update app.py

app.py

@@ -327,7 +327,7 @@ def get_mesh(image, depth, blur_data, loadall):
     ply_file = tempfile.NamedTemporaryFile(suffix='.ply', delete=False)
     o3d.io.write_point_cloud(ply_file.name, pcd)
     print('file - ok')
-    return ply_file.name, ply_file.name, ",".join(mesh_n)
+    return "./tetrahedron.ply", ply_file.name, ",".join(mesh_n)
 
 def blur_image(image, depth, blur_data):
     blur_a = blur_data.split()
@@ -555,7 +555,7 @@ async(c, o, b, p, d, n)=>{
   var intv = setInterval(function(){
     if (document.getElementById("iframe3D")===null || typeof document.getElementById("iframe3D")==="undefined") {
       try {
-      if (BABYLON && BABYLON.Engine && BABYLON.Engine.LastCreatedScene) {
+      if (typeof BABYLON !== "undefined" && BABYLON.Engine && BABYLON.Engine.LastCreatedScene) {
         BABYLON.Engine.LastCreatedScene.onAfterRenderObservable.add(function() { //onDataLoadedObservable
 
           var then = new Date().getTime();