1. A method of real-time 3-D visualization and navigation for interventional procedures, comprising the steps of: determining a position at which data will be acquired; acquiring data at the position; extracting features from the acquired data; building or updating a model described by the extracted features, wherein updating the model includes calculating at least one acquisition parameter of a set of acquisition parameters; displaying 3-D scenes showing the interior or exterior of one or more organs using the model or data extracted from the model; and determining a region for updating.