Developing a Tangible User Interface for Parametric and BIM Applications Using Physical Computing Systems. Emad Al-Qattan 1 , Philip Galanter 2 , Wei Yan 3 1,2,3 Texas A&M University 1,2,3 {emadkkqattan|galanter|wyan}@tamu.edu This paper discusses the development of an interactive and a responsive Tangible User-Interface (TUI) for parametric and Building Information Modeling (BIM) applications. The prototypes presented in this paper utilizes physical computing systems to establish a flexible and intuitive method to engage digital design processes.The prototypes are hybrid UIs that consist of a digital modeling tool and an artifact. The artifact consists of a control system (sensors, actuators, and microcontrollers) and physical objects (architectural elements). The link between both environments associates physical objects with their digital design information to assist users in the digital design process. The integration of physical computing systems will enable the objects to physically respond to analog input and provide real-time feedback to users. The research aims to foster tangible computing methods to extend the capabilities of digital design tools. The prototypes demonstrate a method that allows architects to simultaneously interact with complex architectural systems digitally and physically. Keywords: Physical Computing, Parametric Design, BIM, Tangible UI INTRODUCTION Today, architects and designers use different meth- ods to physically interact with digital models, which are mostly based on GUIs. Some of the tools in use may present more elaborate means of interaction than others, such as in the case of immersive environ- ments, e.g. virtual reality. Yet they remain as graphi- cal representations of physical objects, in return they lack to convey many of the physical qualities asso- ciated with such forms. Additionally, graphic-based methods do not offer the user the same means of in- teraction that naturally occurs in the physical envi- ronment. GUIs in the current practice of design limits - to some extent - the user from exploring and expe- riencing the physical qualities of digitally conceived designs As commonly known, GUIs were developed in the 1970s as new means of interaction that surpassed CUIs (Ishii 2008). However, current practices in digital design utilizing advanced modeling methods such as geometric relationships and design information may suggest the need for an alternative form of interac- tion to manage and comprehend the complexity as- sociated with digital models. Physical design objects are an extraordinary medium for interaction and feedback, and are of great value to the iterative design process as earlier research suggests (Globa et al. 2010). Nevertheless BIM | Concepts - Volume 2 - eCAADe 34 | 621