Résumé : Ambient occlusion is used widely for improving the realism of real-time lighting simulations. We present a new, simple method for storing ambient occlusion values, that is very easy to implement and uses very little CPU and GPU resources. This method can be used to store and retrieve the percentage of occlusion, either alone or in combination with the average occluded direction. The former is cheaper in memory costs, while being slightly less accurate. The latter is slightly more expensive in memory, but gives more accurate results, especially when combining several occluders. The speed of our algorithm is independent of the complexity of either the occluder or the receiving scene. This makes the algorithm highly suitable for games and other real-time applications.