The Effectiveness of Three Dimensional Interaction by James Boritz B. Math. Honours Co-op Computer Science, University of Waterloo, 1988 M. Math. Computer Science, University of Waterloo, 1990 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctor of Philosophy in THE FACULTY OF GRADUATE STUDIES (Department of Computer Science) we accept this thesis as conforming to the required standard The University of British Columbia October 1998 c James Boritz, 1998 Abstract Most interaction with computers today takes place in a two dimensional environ- ment. Even when using three dimensional graphics applications, input is often still restricted to two dimensions. Many believe that the use of three dimensional input devices will alle- viate this restriction and allow for a much more natural human-machine dialog. This thesis seeks to establish how factors dealing with visual feedback and task struc- ture affect the ability to perform interactive tasks in a three dimensional virtual environment. The factors investigated were stereoscopic vision, motion parallax, stimulus arrangement and stimulus complexity. Four tasks were studied. These tasks were: point location, dock- ing, line tracing and curve tracing. All the tasks used a six degree of freedom input device to control a pointer in a three dimensional virtual environment. Four experiments corresponding to the four tasks were conducted to investigate these factors. Among other things the results showed the following. Stereoscopic vision provided a strong bene®t to positioning-based tasks, but this bene®t was weakened in the case of trac- ing tasks. Motion parallax via head-tracking often had no effect upon task performance and where an effect was found it was often detrimental. The position of stimuli in¯uenced per- formance across all of the tasks. The orientation of stimuli in¯uenced performance in the task in which it was varied. ii Contents Abstract ii Contents iii List of Tables ix List of Figures xvii Acknowledgements xxi Dedication xxiii 1 Introduction 1 1.1 Historical Perspective . 2 1.2 Three Dimensional Interaction Terminology . 5 1.2.1 Location . 5 1.2.2 Coordinates . 6 1.2.3 Input and Output Devices . 7 1.2.4 Viewing . 11 1.3 Research Questions . 15 1.4 Effectiveness . 16 iii 1.4.1 Tradeoffs Among Measures . 17 1.5 Motivation . 19 1.5.1 Cognitive . 19 1.5.2 Perceptual . 20 1.5.3 Biomechanical . 22 1.5.4 Technological . 23 1.6 Research Goals . 23 2 Prior Work 26 2.1 Input Device Taxonomies . 28 2.2 Three Dimensions from Two Dimensions . 35 2.2.1 Cross Product of the Input Space . 36 2.2.2 Partitioning the Input Space . 36 2.2.3 Discarding Range Degrees of Freedom . 38 2.2.4 Overloading the Input Mapping . 39 2.3 Three Dimensional Input . 39 2.3.1 Traditional Input Tasks . 40 2.3.2 Virtual Reality Tasks . 41 2.4 Dif®culty of Three Dimensional Interaction . 47 2.4.1 Physical Constraints . 47 2.4.2 Dimensional Integrability . 48 2.4.3 Visual and Geometric Constraints . 49 2.4.4 Dimensional Bias . 50 2.4.5 Directional Bias . 51 2.4.6 Synopsis . 52 iv 3 Experimental Overview 54 3.1 Hypotheses . 54 3.2 Participants . 59 3.3 Equipment . 62 3.3.1 Hardware . 62 3.3.2 Software . 66 3.4 Procedure . 70 3.5 Design . 74 3.6 Training . 75 3.7 Results . 77 3.8 Discussion . 78 3.9 Conclusion . 79 4 Experiment 1: Point Location 80 4.1 Hypotheses . 80 4.2 Participants . 81 4.3 Equipment . 81 4.4 Procedure . 82 4.5 Design . 83 4.6 Training . 84 4.7 Results . 86 4.8 Discussion . 104 4.8.1 Speed . 104 4.8.2 Accuracy . 105 4.8.3 Conciseness . 111 4.8.4 Felicity . 112 v 4.9 Conclusions . 113 5 Experiment 2: Docking 123 5.1 Hypotheses . 123 5.2 Participants . 125 5.3 Equipment . 125 5.4 Procedure . 126 5.5 Design . 127 5.6 Training . 128 5.7 Results . 130 5.8 Discussion . 151 5.8.1 Speed . 151 5.8.2 Accuracy . 155 5.8.3 Conciseness . 160 5.8.4 Felicity . 161 5.9 Conclusions . 162 6 Experiment 3: Line Tracing 169 6.1 Hypotheses . 169 6.2 Participants . 170 6.3 Equipment . 170 6.4 Procedure . 171 6.5 Design . 173 6.6 Training . 174 6.7 Results . 176 6.8 Discussion . 189 vi 6.8.1 Speed . 191 6.8.2 Accuracy . 191 6.8.3 Conciseness . 193 6.8.4 Felicity . 194 6.9 Conclusion . 194 7 Experiment 4: Curve Tracing 204 7.1 Hypotheses . 204 7.2 Participants . 205 7.3 Equipment . 205 7.4 Procedure . 206 7.5 Design . 209 7.6 Training . 210 7.7 Results . 212 7.8 Discussion . 227 7.8.1 Speed . 227 7.8.2 Accuracy . 229 7.8.3 Conciseness . 230 7.8.4 Felicity . 231 7.9 Conclusions . ..