Spatial navigation in immersive virtual environments

Pedestrian movement studies in real environments have shown consistent statistical relationships between ‘configurational’ properties of spatial layouts and movement flows, facilitating prediction of movement from designs. However, these studies are at an aggregate level and say nothing about how individuals make the micro-scale decisions producing these emergent regularities. They do not therefore ‘explain’ movement. Progress on this is difficult since decision-making mechanisms are hard to observe in the real world and the ‘experimenter effect’ is ever-present.

Could the study of movement in immersive virtual environments help? If it could be shown that movement in virtual environments was analogous to movement in real environments then micro behaviour data (head movement, direction of gaze, visual search behaviours) could be obtained through virtual experiments. The aim of this thesis is to explore this possibility by constructing experimental worlds with spatial properties varied to reflect those known to relate to movement in the real world, and asking individuals navigate through them immersively.

Powerful analogies are initially demonstrated between virtual and real behaviour. Two types of micro-scale analysis are then performed: linear analysis, examining how routes are formed and how far linearity is conserved, using measurements of cumulative angular deviation along a path, string-matching algorithms to determine average routes, and analysis of isovist attributes along routes; and positional analysis, focussing upon pausing behaviour, including examining where subjects pause along routes, what choices are made at junctions, how isovist properties of pause-locations compare with an environment’s overall isovist attribute distribution, and correlating pause-point and isovist data. In each analysis, ‘subjective’ movement behaviour is related to ‘objective’ properties of environments.

The experiments show results strongly suggesting how noted aggregate regularities are produced: linearity is strongly conserved, usually following long sight-lines, with pauses in configurationally ‘integrated’ locations offering strategic visual properties, long lines of sight, and large isovist areas.