Product conceptualization through a 3D natural interface considering in real-time spatial and ergonomic restrictions

Currently, the conceptualization of products whose shape and configuration depends on the context is a highly time-consuming process since it has to be achieved asynchronously between the real environment of the product’s usage and the design office -- In general, the designer manually maps the context in order to create a 3D model of it and then to start the product design process -- The literature presents some proposals to digitalize the context without the need of a manual mapping -- However, these approaches are mainly computer-centric tools where the designer is desk-bound and (s)he does not have a clear spatial perception since the interactions with the 3D models are usually based on 2D interfaces -- On this research we aimed to prove that conceptualization of context-dependent products directly over its real environment through gesture-based modeling tools, allows the designer to consider spatial and ergonomic restrictions that the context imposes to the product, through the real-time analysis of the interaction user-context -- In order to prove that, we developed a tool called Äir-Modeling, in which the designer is able to create virtual conceptual products quickly and efficiently, taking advantage of hand gestures meanwhile (s)he is interacting directly with the real scenario in an Augmented Reality (AR) environment -- Air-Modeling also allows a continuous evaluation of the user postures involved in the product usage and assembly in order to analyze ergonomic risks, and perform the necessary changes in the product shape or configuration from early stages of the design process -- A test was carried out to prove the effects of the use of the proposed tool in the design process in comparison with the traditional way through traditional CAD packages -- We found that the real context can be used as an information input in real-time during product conceptualization -- Beside this, we could notice that virtual parts creation is more efficient from a 3D input than a 2D interface such as a mouse or a keyboard -- This was reflected in the experiment carried out in which 21 users conceptualized a bookcase for a given context using both Air-Modeling and a commercial CAD tool -- It was obtained a reduction in the modeling time using our tool on 76% of the cases with a final average reduction of 44%. Finally, we concluded that 3D modeling in AR environments using the hands as interface and the context as an information input in realtime, allows the designer to conceptualize potential solutions in quick and efficient manner, exploiting as much as possible, inspirational instants -- On the other hand, modeling in a natural scale directly over the real scene prevents the designer to draw his/her attention on dimensional details but allows him/her to focus on the product itself and its relation with the environment -- Besides, developing 3D models in natural scale allows analyzing the interaction between the user, the context and the virtual model for determining ergonomic issues related with the product usage or assembly process -- We believe that this kind of technologies makes the development of customized products more efficient by adding spatial and ergonomic restrictions to the conceptualization process in real-time -- This facilitates the convergence to the design solution, possibly avoiding some iteration in the design proces