In Proc. TEI'19. Full Paper 

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Several systems have illustrated the concept of interactive fabrication, i.e. rather than working through a digital editor, users make edits directly on the physical workpiece. However, so far the interaction has been limited to turn-taking, i.e., users first perform a command and then the system responds with physical feedback. In this paper, we present a first step towards interactive fabrication that changes the workpiece while the user is manipulating it.

FormFab reshapes the workpiece while users are moving their hands. This enables users to interactively explore different sizes of a shape with a single interaction.

To achieve this, our system FormFab does not add or subtract material but instead reshapes it (formativefabrication). A heat gun attached to a robotic arm warms up a thermoplastic sheet until it becomes compliant; users then control a pneumatic system that applies either pressure or vacuum thereby pushing the material outwards or pulling it inwards.

To track the user interaction, FormFab users wear a motion capture marker and a pressure sensor on their index finger. The marker is detected by a motion capture system (OptiTrack) and used to determine where the user is interacting on the workpiece. In addition, the pressure sensor is used to determine the beginning and end of the interaction.

CONCLUSION

In this paper, we showed a first prototype implementation of an interactive fabrication system that provides the user with physical feedback while the user is interacting. While the first step of selecting the area still followed the turntaking model, the second step of defining the size of the shape provided the user with simultaneous physical feedback, thereby bringing the principles of direct manipulation to the editing of physical objects.