This paper describes an approach towards the interaction with 3D representations of large document collections. The goal was to provide the user with a highly dynamic environment in which even the very mapping strategy to position documents in space can be adjusted by the user depending on the specific task at hand, on his preferences, or on the context. A modification to the FDP algorithm is proposed, as well as a new gesture-based interaction paradigm in which the user can explore and search information in the collection just by simple hand movements. An experimental user evaluation was carried on to investigate the impact of the proposed approach on the precision of the mental model built by users through exploration, on the effectiveness in information search tasks, and on the general user satisfaction and perception of utility.