Many technical domains, as mechanical part assembling, or architectural design, require 3D object handling and visualization that take into account real world parameters, hidden in the numerical world. For example, while designing a mechanical part with CAD software, an engineer would like to test an assembling task so as to avoid problems as relative positioning. New devices (spatial mice, data-gloves, etc.) are too generic and don’t provide the required feedback; Tangible User Interfaces (TUIs) are often based on complex techniques and require expensive and bulky hardware. Moreover, most of time they don’t permit to use other objects than those initially foreseen. In this paper, we present a TUI based platform that allows to use any everyday life real world object to handle and visualize any 3D numerical model. This platform is based on a video capture system: once a real world object, called interactor, has been acquired, it is possible to associate it with a 3D numerical model. Then, any operation (planar translation and rotation) performed with an interactor is reflected into the application. This solution is non intrusive and is based on interaction objects that are all the more in balance with the user task as they have been chosen by the application designer.Read less <