Parameters influencing the perception of geometrical deviations in a virtual environment

On car exteriors, geometrical variation, stemming from the manufacturing process, can distort the visible relationships between parts, i.e. the split-lines. In the automotive industry, non-nominal visualization is often implemented as a part of early concept reviews. Visualizing the results from a Computer-Aided Tolerancing analysis in a virtual environment allows to evaluate what deviations will be visible to customers and whether they can have a negative influence on the perceived product quality. The geometry, colors and materials of parts make some split-lines more visually sensitive than others because on them, potential deviations are especially disturbing to the onlooker. Moreover, the visual sensitivity is influenced by the context of product interaction in terms of illumination, reflections and the observer's viewing angle. These factors need to be taken into account when determining tolerance levels to ensure that an industrial design concept will look good on ce produced. This paper presents a study of the influence split-line geometry and several visualization parameters have on the ability of test persons to identify geometrical deviations in a number of computer generated images. Additionally, eye-tracking was performed to identify what areas of the split-lines the test persons looked at while performing the task. The results confirm that the included splitlines are not equally sensitive to variation. Further, it is shown that the visualization settings indeed have an influence on the ability to detect variation but that the most sensitive settings differ between combinations of deviations and split-lines.