Several projects at Graphitech have made current use of multiple modalities thus maximising the support for the user, bringing a positive impact on how interaction is performed. In this context the idiom “modality” is used to refer to the syntactic and semantic properties of a signal; on the contrary the word “medium”, is adopted to focus on the production and transmission of signals...

One of the most significant advantages of adopting multiple modalities is in the broader perceptual and conceptual bandwidth available to the user to handle the data he is interacting with. Graphitech R&D activities have promoted the integration between user and computer through the development of interfaces that take advantage of the combined use of gesture, voice or gaze. The possibility to extract semantic information related to the interaction process has been also explored thus allowing the user to access more complex and compelling functions in an ease and natural manner. This approach, borrowed from computational linguistics, has been brought into the HCI domain to enhance the overall effectiveness of the system and to handle the properties embedded in the virtual scene in a more efficient way.{igallery 7}R&D activities have also brought to the development of adequate feedback systems necessary to complete the multiple-sensory channel interface by providing the user, through analogous means, with information related to the 3D-world he is manipulating.

The main objective of the research activities promoted by GraphiTech was to develop novel solutions that could fill this gap through an innovative design methodology specifically tailored for both stylists' and engineers' needs. In brief the following scientific areas have been subject of research within this application domain:

• User and cognitive task analysis of multimodal interfaces.
• Visual languages and multimodal input to describe model constraints.
• Extended virtual and augmented environments to support design.
• Efficient search algorithms to match sketches against multimedia databases.
• Intelligent user interfaces for product design.
• Interactive building of precise 3D models from sketches.
• Usability studies and empirical evaluation of multimodal interfaces.

Specifically, as far as design of free-form surfaces within immersive environments is concerned, we have been working on:

• Extended design environments ranging from personal design assistants, through desktop monitors, to the CAVE.
• Novel 3D interaction techniques to create and manipulate free-form surfaces in Virtual Environments in conjunction with different input and output devices.
• Mathematical models and representation schemes for free-form surfaces, together with the algorithms required for high-quality rendering of these surfaces.