Investigating a Multi-touch User Interface for Three-dimensional 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 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 affecting the multitouch interface when applied to CAD operations. This problem is magnified when it comes to 3D CAD operations. The aim of this research is to (1) study the key elements of the multitouch interface, (2) identify the factors affecting the performance of a multitouch-enabled 3D modeling environment, and (3) lay a foundation for future research and highlight the direction for researchers and developers to extend the multitouch interface for CAD modeling operations and other engineering applications. We have conducted mouse emulation experiments in order to achieve the goal. We compare the standard mouse device with two finger-based touch interaction techniques (drag state finger touch and track state finger touch) for 3D CAD modeling operations. The mouse device outperformed the finger touch techniques and yielded statistically better performance results in terms of both task completion time and error rates. The paired t-test indicated that both the task completion time and error rates are statistically the same for the two finger touch techniques under investigation. However, the error concentration observed from the experiments revealed that the track state technique is more suited for edge selection tasks as compared to the drag state technique. Regardless, both the finger touch techniques suffered from lack of precise dimension control while executing the tasks. The presence of grid had a significant desirable effect on the error rate.