Wrap generate in try-except to surface backend errors

app.py

@@ -136,31 +136,41 @@ def generate(files: Any):
         )
         return None, None, err_placeholder, status
 
-    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
-    model.to(device)
+    import traceback
+    try:
+        device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+        model.to(device)
 
-    gaussians = model(result.images)[0]
+        gaussians = model(result.images)[0]
 
-    video_path = tempfile.mktemp(suffix=".mp4")
-    ply_path = tempfile.mktemp(suffix=".ply")
+        video_path = tempfile.mktemp(suffix=".mp4")
+        ply_path = tempfile.mktemp(suffix=".ply")
 
-    viz.turntable(gaussians, video_path, sweep_deg=None)
-    gaussians.save_ply(ply_path)
+        viz.turntable(gaussians, video_path, sweep_deg=None)
+        gaussians.save_ply(ply_path)
 
-    center, radius = viz.scene_center_radius(gaussians)
-    cx, cy, cz = center.tolist()
+        center, radius = viz.scene_center_radius(gaussians)
+        cx, cy, cz = center.tolist()
 
-    viewer_html = build_viewer_iframe(ply_path, cx=cx, cy=cy, cz=cz, r=radius)
+        viewer_html = build_viewer_iframe(ply_path, cx=cx, cy=cy, cz=cz, r=radius)
 
-    status = (
-        f"Loaded {result.image_count} still image(s) and selected "
-        f"{result.selected_video_frames} of {result.decoded_video_frames} decoded video frame(s).\n"
-        f"Total ZipSplat views: {len(result.images)}."
-    )
-    if result.warnings:
-        status += "\n\nWarnings:\n" + "\n".join(result.warnings)
+        status = (
+            f"Loaded {result.image_count} still image(s) and selected "
+            f"{result.selected_video_frames} of {result.decoded_video_frames} decoded video frame(s).\n"
+            f"Total ZipSplat views: {len(result.images)}."
+        )
+        if result.warnings:
+            status += "\n\nWarnings:\n" + "\n".join(result.warnings)
 
-    return video_path, ply_path, viewer_html, status
+        return video_path, ply_path, viewer_html, status
+    except Exception as e:
+        err_msg = f"Backend Crash during generation:\n{traceback.format_exc()}"
+        err_html = (
+            f'<div style="height: 500px; padding: 20px; overflow-y: auto; '
+            f'background: #080b12; color: #f87171; border-radius: 12px; font-family: monospace;">'
+            f"{err_msg.replace(chr(10), '<br>')}</div>"
+        )
+        return None, None, err_html, err_msg
 
 
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