diff --git a/Isosurfacing_3/examples/Isosurfacing_3/contouring_discrete_data.cpp b/Isosurfacing_3/examples/Isosurfacing_3/contouring_discrete_data.cpp
index 7b35dd37d2d..af61c6a44c8 100644
--- a/Isosurfacing_3/examples/Isosurfacing_3/contouring_discrete_data.cpp
+++ b/Isosurfacing_3/examples/Isosurfacing_3/contouring_discrete_data.cpp
@@ -89,6 +89,11 @@ void run_dual_contouring(const Grid& grid,
     }
   }
 
+  // If the gradient was not known analytically, we could use:
+  // - Finite_difference_gradient_3 to use finite difference to compute it from values;
+  // - the function below to use finite difference _and_ store the values at the grid vertices
+  //     gradients.compute_discrete_gradients(values);
+
   Domain domain { grid, values, gradients };
 
   Point_range points;
diff --git a/Isosurfacing_3/include/CGAL/Isosurfacing_3/Interpolated_discrete_gradients_3.h b/Isosurfacing_3/include/CGAL/Isosurfacing_3/Interpolated_discrete_gradients_3.h
index 62b9da44e0b..f4c5dd9f8e5 100644
--- a/Isosurfacing_3/include/CGAL/Isosurfacing_3/Interpolated_discrete_gradients_3.h
+++ b/Isosurfacing_3/include/CGAL/Isosurfacing_3/Interpolated_discrete_gradients_3.h
@@ -62,9 +62,9 @@ public:
     m_gradients.resize(nv);
   }
 
-  // computes and stores gradients at the vertices of the grid
-  // \tparam ValueField must be a model of `IsosurfacingValueField_3`
-  // \param values a field of values whose gradient are being computed
+  /// computes (using finite difference) and stores gradients at the vertices of the grid.
+  /// \tparam ValueField must be a model of `IsosurfacingValueField_3`
+  /// \param values a field of values whose gradient are being computed
   template <typename ValueField>
   void compute_discrete_gradients(const ValueField& values)
   {