Examples of feature requirements for VR tasks.

Left column names example tasks, middle column lists features which need to be implemented to run the given task, right column names software components which can fulfil the respective requirement. Trap-lining refers to a type of route optimisation task where navigators have to find and collect resources distributed around an environment [34, 35]. Eye tracking refers to the inclusion of 3D gaze recording in other virtual spatial tasks, see also section “Example of interface driven design” for a discussion on implementing gaze-based ray-casting within the VNT. VNT modules are designed to be highly modular and re-usable, which is shown by the fact that the same modules can fulfil requirements across different experiments. Note for example that while data logging is provided by the UXF for our showcase triangle completion study, we also provide our own data logging functionalities in the Util module of the VNT and use it for data handling in an ongoing eye tracking study.