The influence of olfaction on the perception of high-fidelity computer graphics

The computer graphics industry is constantly demanding more realistic images and animations. However, producing such high quality scenes can take a long time, even days, if rendering on a single PC. One of the approaches that can be used to speed up rendering times is Visual Perception, which exploits the limitations of the Human Visual System, since the viewers of the results will be humans. Although there is an increasing body of research into how haptics and sound may affect a viewer's perception in a virtual environment, the in uence of smell has been largely ignored. The aim of this thesis is to address this gap and make smell an integral part of multi-modal virtual environments. In this work, we have performed four major experiments, with a total of 840 participants. In the experiments we used still images and animations, related and unrelated smells and finally, a multi-modal environment was considered with smell, sound and temperature. Beside this, we also investigated how long it takes for an average person to adapt to smell and what affect there may be when performing a task in the presence of a smell. The results of this thesis clearly show that a smell present in the environment firstly affects the perception of object quality within a rendered image, and secondly, enables parts of the scene or the whole animation to be selectively rendered in high quality while the rest can be rendered in a lower quality without the viewer noticing the drop in quality. Such selective rendering in the presence of smell results in significant computational performance gains without any loss in the quality of the image or animations perceived by a viewer.