A study of techniques for selecting and positioning objects in immersive VEs: effects of distance, size, and visual feedback

We present results of a formal evaluation of three direct manipulation interaction techniques for picking and posi- tioning objects in VEs: the "classical" virtual hand, ray- casting, and the Go-Go techniques. Our goal was to assess and compare the two most basic metaphors for selection and manipulation in VEs: virtual pointer and virtual hand. The main variables of interest were distance to and size of objects, interaction technique, and visual feedback. The results of the studies suggest that within the user-centered coordinate system, virtual pointing is an essentially two- dimensional metaphor, while the virtual hand is a three- dimensional metaphor. We also found that for some appli- cations the "classical" virtual hand technique appears to be obsolete and may be replaced by the ray or Go-Go tech- niques without a reduction in user performance. The paper reports these and other experimental results and discusses their implications for the design of VEs.