Compressed Multisampling For Efficient Hardware Edge Antialiasing

Today's hardware graphics accelerators incorporate techniques to antialias edges and minimize geometry-related sampling artifacts. Two such techniques, brute force supersampling and multisampling, increase the sampling rate by rasterizing the triangles in a larger antialiasing buffer that is then filtered down to the size of the framebuffer. The sampling rate is proportional to the number of subsamples in the antialiasing buffer and, when no compression is used, to the memory it occupies. In turn, a larger antialiasing buffer implies an increase in bandwidth, one of the limiting resources for today's applications. In this paper we propose a mechanism to compress the antialiasing buffer and limit the bandwidth requirements while maintaining higher sampling rates. The usual framebuffer-related functions of OpenGL are supported: alpha blending, stenciling, color operations, and color masking. The technique is scalable, allowing for user-specified maximal and minimal sampling rates. The compression scheme includes a mechanism to nicely degrade the quality when too much information would be required. A lower bound on the quality of the resulting image is also available since the sampling rate will never be less than the user-specified minimal rate. The compression scheme is simple enough to be incorporated into standard hardware graphics accelerators. Software simulations show that, for a given bandwidth, our technique offers improved visual results over multisampling schemes

Interactive Spaces Natural interfaces supporting gestures and manipulations in interactive spaces

This doctoral dissertation focuses on the development of interactive spaces through the use of natural interfaces based on gestures and manipulative actions. In the real world people use their senses to perceive the external environment and they use manipulations and gestures to explore the world around them, communicate and interact with other individuals. From this perspective the use of natural interfaces that exploit the human sensorial and explorative abilities helps filling the gap between physical and digital world. In the first part of this thesis we describe the work made for improving interfaces and devices for tangible, multi touch and free hand interactions. The idea is to design devices able to work also in uncontrolled environments, and in situations where control is mostly of the physical type where even the less experienced users can express their manipulative exploration and gesture communication abilities. We also analyze how it can be possible to mix these techniques to create an interactive space, specifically designed for teamwork where the natural interfaces are distributed in order to encourage collaboration. We then give some examples of how these interactive scenarios can host various types of applications facilitating, for instance, the exploration of 3D models, the enjoyment of multimedia contents and social interaction. Finally we discuss our results and put them in a wider context, focusing our attention particularly on how the proposed interfaces actually improve people’s lives and activities and the interactive spaces become a place of aggregation where we can pursue objectives that are both personal and shared with others

Interactive Spaces Natural interfaces supporting gestures and manipulations in interactive spaces

This doctoral dissertation focuses on the development of interactive spaces through the use of natural interfaces based on gestures and manipulative actions. In the real world people use their senses to perceive the external environment and they use manipulations and gestures to explore the world around them, communicate and interact with other individuals. From this perspective the use of natural interfaces that exploit the human sensorial and explorative abilities helps filling the gap between physical and digital world. In the first part of this thesis we describe the work made for improving interfaces and devices for tangible, multi touch and free hand interactions. The idea is to design devices able to work also in uncontrolled environments, and in situations where control is mostly of the physical type where even the less experienced users can express their manipulative exploration and gesture communication abilities. We also analyze how it can be possible to mix these techniques to create an interactive space, specifically designed for teamwork where the natural interfaces are distributed in order to encourage collaboration. We then give some examples of how these interactive scenarios can host various types of applications facilitating, for instance, the exploration of 3D models, the enjoyment of multimedia contents and social interaction. Finally we discuss our results and put them in a wider context, focusing our attention particularly on how the proposed interfaces actually improve people’s lives and activities and the interactive spaces become a place of aggregation where we can pursue objectives that are both personal and shared with others