fixed reindex in render2d

tools/render2d.py

@@ -175,16 +175,29 @@ def process_frame(args) -> Tuple[int, np.ndarray, Optional[Path]]:
     lidar_data["normalized_range"] = 1 / np.sqrt(
         lidar_data["x"] ** 2 + lidar_data["y"] ** 2 + lidar_data["z"] ** 2
     )
+    # check for zero values in normalized_range and output the x y and z values for them
+    zero_range_indices = lidar_data[lidar_data["normalized_range"] == 0].index
+    if not zero_range_indices.empty:
+        print(
+            f"Warning: Found {len(zero_range_indices)} points with zero normalized range at indices: {zero_range_indices.tolist()}"
+        )
+        print(
+            "X, Y, Z values for these points:",
+            lidar_data.loc[zero_range_indices, ["x", "y", "z"]].to_numpy(),
+        )
+        # Set zero values to NaN to avoid issues with training
+        lidar_data.loc[zero_range_indices, "normalized_range"] = np.nan
+
     projection_data = lidar_data.pivot(
         index="vertical_position",
         columns="horizontal_position",
         values="normalized_range",
     )
     projection_data = projection_data.reindex(
-        columns=range(horizontal_resolution), fill_value=0
+        columns=range(horizontal_resolution), fill_value=np.nan
     )
     projection_data = projection_data.reindex(
-        index=range(vertical_resolution), fill_value=0
+        index=range(vertical_resolution), fill_value=np.nan
     )
     projection_data, output_horizontal_resolution = crop_projection_data_to_roi(
         projection_data, roi_angle_start, roi_angle_width, horizontal_resolution