Abstract: We present "contact levels of detail" (CLOD), a novel concept for multiresolution collision detection. Given a polyhedral model, our algorithm automatically builds a "dual hierarchy," both a multiresolution representation of the original model and its bounding volume hierarchy for accelerating collision queries.We have proposed various error metrics, including object-space errors, velocity dependent gap, screen-space errors and their combinations. At runtime, our algorithm uses these error metrics to select the appropriate levels of detail independently at each potential contact location. Compared to the existing exact collision detection algorithms, we observe significant performance improvement using CLODs on some benchmarks, with little degradation in the visual rendering of simulations.