Analysis of Performance in Precise 3D Curve Input Tasks in Virtual Reality

Predictive models for human performance, such as Fitts’ Law [2] and the Steering Law [1], are useful tools for developers of interactive applications because they help guide us toward effective and efficient interface designs. In this poster, we present a mathematical model in this style that is meant to characterize performance in precise, continuous 3D input tasks, such as making an exact tracing of a 3D curve presented in virtual reality (VR). This continuous, sweeping style of 3D input has important implications for interactive visualizations. We utilize within our group, direct input of curved 3D paths in several visualization contexts, for example, free-form modeling for designing scientific visualizations and creating 3D illustrations [3] and selecting streamlines and regions of interest in interactive 3D fluid flow visualizations. [5] In addition, a current project seeks to utilize haptic-guided input of 3D curved paths for querying 3D datasets and selecting fine detail within dense visualizations of neural fiber tracts in the brain. Increased knowledge of our ability to control precise 3D input is likely lead to improved interaction and more productive user experiences in these interactive visualizations. One of the challenges in working with this style of input is that it can be difficult to control with precision. In a precursor to this work, we developed two new interaction techniques, a two-handed 3D tape drawing interface and a one-handed 3D drag drawing interface. Each significantly improves the precision of continuous 3D input as compared to standard modes of tracking a moving prop through the air. Full details of these interfaces and of the tracing experiment described briefly below have been presented elsewhere. [4] The novel contribution of the work presented here (and adapted from Daniel Keefe’s dissertation [3]) is the derivation of a performance model for this style of input from theory in related disciplines and the verification of this model using experimental data from the tracing experiment.