Finger-based multitouch interface for performing 3D CAD operations

The area of multitouch interaction research is at its infancy. The commercial sector has seen an exponential growth in this area with ubiquitous products like Apple i-Phone, i-Pad, and Microsoft surface table. In spite of their popularity, developers are still finding it difficult to extend this novel interface to engineering applications such as computer aided design (CAD), due to insufficient understanding of the factors that affect the multitouch interface interaction when applied to CAD operations. The objective of this research is to (1) outline the key elements of the multitouch interface for CAD, (2) identify the factors affecting the performance of a multitouch enabled CAD modeling environment, and (3) lay a foundation for future research and highlight the directions for extending the multitouch interface for CAD and other engineering applications. To demonstrate specific results we have conducted mouse emulation experiments. We compared the performance of two finger touch-based interaction techniques (drag state finger touch and track state finger touch) and a standard mouse device for 3D CAD modeling operations. The results indicated that both the task completion time and error rates are statistically the same for both the finger touch-based techniques. However, the error concentration observed from the experiments revealed that for the edge selection tasks, the track state technique is more suited than the drag state technique. Both the finger touch-based techniques suffered from precise dimension control while executing the tasks. The inclusion of a grid on the design space for modeling purpose reduced user errors. The mouse device outperformed both the finger touch-based techniques and yielded statistically better results in terms of task completion time and error rates.