Sander E. M. Jansen

Effects of field-of-view restrictions on speed and accuracy of manoeuvring

Effects of field-of-view restrictions on the speed and accuracy of participants performing a real-world manoeuvring task through an obstacled environment were investigated. Although field-of-view restrictions are known to affect human behaviour and to degrade performance for a range of different tasks, the relationship between human manoeuvring performance and field-of-view size is not known. This knowledge is essential to evaluate a trade-off between human performance, cost, and ergonomic aspects of field-of-view limiting devises like head-mounted displays and night vision goggles which are frequently deployed for tasks involving human motion through environments with obstacles. In this study the speed and accuracy of movement were measured in 15 participants (8 men, 7 women, 22.9 ± 2.8 yr. of age) traversing a course formed by three wall segments for different field-of-view restrictions. Analysis showed speed decreased linearly with decreasing field-of-view extent, while accuracy was consistently reduced for all restricted field-of-view conditions. Present results may be used to evaluate cost and performance trade-offs for field-of-view restricting devices deployed to perform time-limited human-locomotion tasks in complex structured environments, such as night-vision goggles and head-mounted displays.

Exploiting Motion Capture to Enhance Avoidance Behaviour in Games

Realistic simulation of interacting virtual characters is essential in computer games, training and simulation applications. The problem is very challenging since people are accustomed to real-world situations and thus, they can easily detect inconsistencies and artifacts in the simulations. Over the past twenty years several models have been proposed for simulating individuals, groups and crowds of characters. However, little effort has been made to actually understand how humans solve interactions and avoid inter-collisions in real-life. In this paper, we exploit motion capture data to gain more insights into human-human interactions. We propose four measures to describe the collision-avoidance behavior. Based on these measures, we extract simple rules that can be applied on top of existing agent and force based approaches, increasing the realism of the resulting simulations.

Restricting the vertical and horizontal extent of the Field-of-View: Effects on manoeuvring performance

It is known that Field-of-view restrictions affect distance estimation, postural equilibrium, and the ability to control heading. These are all important factors when manoeuvring on foot through complex structured environments. Although considerable research has been devoted to the horizontal angular extent of the Field-of-View (FoV), rather less attention has been paid to the vertical angle. The present study investigated the effects of both vertical and horizontal FoV restriction on manoeuvring performance and head movement while traversing an obstacle course consisting of three different types of obstacles. A restriction of both the horizontal and vertical angle of the visual field resulted in increased time needed to traverse the course. In addition, the extent of head movement during traversal was affected by vertical, but not horizontal viewing restriction. Furthermore, it was investigated if performance could be improved by altering the orientation of the visual field instead of its dimensions. The results do not indicate this. The findings of this study can be used to formulate requirements for the selection and development of field-of-view limiting devices, such as head-mounted displays and night-vision goggles.

Effects of field-of-view restriction on manoeuvring in a 3-D environment

Field-of-view (FOV) restrictions are known to affect human behaviour and to degrade performance for a range of different tasks. However, the relationship between human locomotion performance in complex environments and FOV size is currently not fully known. This paper examined the effects of FOV restrictions on the performance of participants manoeuvring through an obstacle course with horizontal and vertical barriers. All FOV restrictions tested (the horizontal FOV was either 30°, 75° or 120°, while the vertical FOV was always 48°) significantly reduced performance compared to the unrestricted condition. Both the time and the number of footsteps needed to traverse the entire obstacle course increased with a decreasing FOV size. The relationship between FOV restriction and manoeuvring performance that was determined can be used to formulate requirements for FOV restricting devices that are deployed to perform time-limited human locomotion tasks in complex structured environments, such as night-vision goggles and head-mounted displays used in training and entertainment systems.

Obstacle Crossing With Lower Visual Field Restriction: Shifts in Strategy

ABSTRACT In this study, the authors investigated how restriction of the vertical viewing angle influences obstacle-crossing behavior. Twelve participants stepped over obstacles of different dimensions while wearing visual-field-restricting goggles. Using full-body motion capture, several kinematic measures were extracted and analyzed. Results indicate that both a 40° and 90° vertical viewing angle yielded increased step length and toe clearance as compared to an unrestricted view (i.e., 135°), whereas speed remained unaltered. A further decrease (to 25°) caused participants to slow down in addition to a further increase of step length and toe clearance. These results are discussed in terms of a change in priorities, from conservation of energy and time to safety.

Effects of horizontal field-of-view restriction on manoeuvring performance through complex structured environments

Field-of-view (FOV) restrictions are known to affect human behaviour and to degrade performance for a range of different tasks. A proposed cause for this performance impairment is the predominant activation of the ventral cortical stream as compared to the dorsal stream. This may compromise the ability to control heading as well as degrade the processing of spatial information [Patterson et al. 2006]. Furthermore, the peripheral visual field is important in maintaining postural equilibrium [Turano et al. 1993]. These are all significant factors when manoeuvring through complex structured environments. We discuss here two experiments investigating the influence of horizontal FOV-restriction on manoeuvring performance through real-world structured environments. The results can help determine requirements for the selection and development of FOV limiting devices such as Head-Mounted Displays (HMDs).