Update app.py

app.py

@@ -376,15 +376,17 @@ with gr.Blocks(css=css) as demo:
               } 
               var cntxt = document.getElementsByClassName(\"model3D\")[0].getElementsByTagName(\"canvas\")[0].getContext(\"webgl2\");
               this.innerText = cntxt;
-
-BABYLON.Engine.LastCreatedScene.getEngine().onEndFrameObservable.add(function() {
-  if (BABYLON.Engine.LastCreatedScene.activeCamera.metadata.screenshot === true) {
-    BABYLON.Engine.LastCreatedScene.activeCamera.metadata.screenshot = false;
-    try {
-      BABYLON.Tools.CreateScreenshotUsingRenderTarget(BABYLON.Engine.LastCreatedScene.getEngine(), BABYLON.Engine.LastCreatedScene.activeCamera, { width: 310 }, (durl) => { document.getElementById(\"img_out\").src = durl; });
-    } catch(e) { alert(e); }
-  }
-});
+              BABYLON.Engine.LastCreatedScene.activeCamera.metadata.screenshot = true;
+
+              BABYLON.Engine.LastCreatedScene.getEngine().onEndFrameObservable.add(function() {
+                if (BABYLON.Engine.LastCreatedScene.activeCamera.metadata.screenshot === true) {
+                  BABYLON.Engine.LastCreatedScene.activeCamera.metadata.screenshot = false;
+                  try {
+                    BABYLON.Tools.CreateScreenshotUsingRenderTarget(BABYLON.Engine.LastCreatedScene.getEngine(), BABYLON.Engine.LastCreatedScene.activeCamera, { width: 310 }, (durl) => { document.getElementById(\"img_out\").src = durl; });
+                  } catch(e) { alert(e); }
+                  // https://forum.babylonjs.com/t/best-way-to-save-to-jpeg-snapshots-of-scene/17663/11
+                }
+              });
             '/>webgl2</a><br/><img src='' id='img_out'/>""")
             render = gr.Button("Render")