Abstract: We present a novel aging technique that simulates the deformation of an object caused by repetitive impacts over long periods of time. Our semi-automatic system deteriorates the surface of an object by hitting it with another object. An empirical simulation modifies the object surface to represent the small depressions caused by each impact. This is done by updating the vertices of an adaptively refined object mesh. The simulation is efficient, applying hundreds of impacts in a few seconds. The user controls the simulation through intuitive parameters. Because the simulation is rapid, the user can easily adjust the parameters and see the effect of impacts interactively. The models processed by our system exhibit the cumulative aging effects of repetitive impacts, significantly increasing their realism.