In this article, we study the interaction between two nanoscopic growth mechanisms during physical vapor deposition, namely, biased diffusion and atomic level shadowing by defects such as islands and ledges, by molecular dynamics simulations. The material system described here is homoepitaxy of Cu on Cu(111). We find that the phenomenon of biased diffusion has a strong effect on the details of the shadowing process at the atomic scale. In the particular case of deposition by high energy particles at off-normal angles, biased diffusion suppresses the shadowing effect that dominates at low energy and off-normal angles. This can be understood from an analysis of the potential energy landscape as seen by the arriving adatom. (C) 2005 American Vacuum Society.