fix: Unavaialble field data for some surfaces.

doc/changelog.d/4345.fixed.md

@@ -0,0 +1 @@
+Unavaialble field data for some surfaces.

src/ansys/fluent/core/file_session.py

@@ -186,7 +186,20 @@ def get_field_data(
             | PathlinesFieldDataRequest
         ),
     ) -> Dict[int | str, Dict | np.array]:
-        """Get the surface, scalar, vector or path-lines field data on a surface."""
+        """Get the surface, scalar, vector or path-lines field data on a surface.
+
+        Returns
+        -------
+        Dict[int | str, Dict | np.array]
+            Field data for the requested surface. If field data is unavailable for the surface,
+            an empty array is returned and a warning is issued. Users should always check
+            the array size before using the data.
+
+            Example:
+                data = get_field_data(field_data_request)[surface_id]
+                if data.size == 0:
+                    # Handle missing data
+        """
         if isinstance(obj, SurfaceFieldDataRequest):
             return self._get_surface_data(**obj._asdict())
         elif isinstance(obj, ScalarFieldDataRequest):
@@ -973,7 +986,20 @@ def get_field_data(
             | PathlinesFieldDataRequest
         ),
     ) -> Dict[int | str, Dict | np.array]:
-        """Get the surface, scalar, vector or path-lines field data on a surface."""
+        """Get the surface, scalar, vector or path-lines field data on a surface.
+
+        Returns
+        -------
+        Dict[int | str, Dict | np.array]
+            Field data for the requested surface. If field data is unavailable for the surface,
+            an empty array is returned and a warning is issued. Users should always check
+            the array size before using the data.
+
+            Example:
+                data = get_field_data(field_data_request)[surface_id]
+                if data.size == 0:
+                    # Handle missing data
+        """
         if isinstance(obj, SurfaceFieldDataRequest):
             return self._get_surface_data(**obj._asdict())
         elif isinstance(obj, ScalarFieldDataRequest):

src/ansys/fluent/core/services/field_data.py

@@ -577,7 +577,20 @@ def get_field_data(
             | PathlinesFieldDataRequest
         ),
     ) -> Dict[int | str, Dict | np.array]:
-        """Get the surface, scalar, vector or path-lines field data on a surface."""
+        """Get the surface, scalar, vector or path-lines field data on a surface.
+
+        Returns
+        -------
+        Dict[int | str, Dict | np.array]
+            Field data for the requested surface. If field data is unavailable for the surface,
+            an empty array is returned and a warning is issued. Users should always check
+            the array size before using the data.
+
+            Example:
+                data = get_field_data(field_data_request)[surface_id]
+                if data.size == 0:
+                    # Handle missing data
+        """
         if isinstance(obj, SurfaceFieldDataRequest):
             return self._get_surface_data(**obj._asdict())
         elif isinstance(obj, ScalarFieldDataRequest):
@@ -1185,13 +1198,19 @@ def _extract_field(field_datatype, field_size, chunk_iterator):
                     payload_tag_id = None
             field = None
             if payload_tag_id is not None:
-                field = _extract_field(
-                    _FieldDataConstants.proto_field_type_to_np_data_type[
-                        payload_info.fieldType
-                    ],
-                    payload_info.fieldSize,
-                    chunk_iterator,
-                )
+                if payload_info.fieldSize > 0:
+                    field = _extract_field(
+                        _FieldDataConstants.proto_field_type_to_np_data_type[
+                            payload_info.fieldType
+                        ],
+                        payload_info.fieldSize,
+                        chunk_iterator,
+                    )
+                else:
+                    warnings.warn(
+                        f"Field data is not available for surface: {surface_id}"
+                    )
+                    field = np.array([])
 
             if self._callbacks_provider is not None:
                 for callback_data in self._callbacks_provider.callbacks():