Interactions between polluted atmosphere and materials lead to an early aging of numerous buildings and
monuments. This weathering process leads to important changes in appearance, from color blackening to smallscale
geometric alterations: a black crust grows onto parts of affected surfaces, depending on the geometry of the
object as well as on its environment. In this paper, we present a method to simulate this very important
weathering process. Our method is physically inspired and provides full control to designers, keeping plausible
results. First, specific polluted zones are detected according to their real physical classification. Then, the
modifications of aspect of each zone are computed. Our results demonstrate that our model matches well the
observed behavior of real-world monuments and buildings affected by atmospheric pollution
