The main objective of the module is to experiment the complex 3D modelling process of design products from the geometrical and representation point of view. Starting from the sketch of the project, the idea is refined through increasingly detailed drawings, up to the technical executive representation. This defines the main communication tool of the project between the designer and his producer, so it requires a formal and regulatory correctness. But this structured drawing also represents the starting point for the construction of 3D models with increasing geometric complexity, up to the definition of reality-based 3D models, from which realistic, immersive or functional images, 3D prints and Augmented Reality visualization can be extracted. Inversely to this process, always structured within the design workflow, there is the process of reverse modeling, understood as the translation of an existing product in its digital copy, starting for the design intervention on the existing. The drawing becomes the means of creation of the design product, while the representation assumes the dual role of prefiguration of the idea and virtual window of reality. During the course students will learn how to manage the models listed above, acquiring the ability to control the dual path of design, from real to virtual and back. In this context, the differences between the representations for the project and for the survey, the scales of representation and the levels of accuracy in the representation and modeling will be investigated