An Intelligent Virtual Environment for Designers with Reduced Motor Abilities

Conventional CAD modelling software demands substantial utilisation of input modalities like the keyboard and mouse for creating 3-dimensional (3D) models. The dexterity measures involved in controlling input modalities could pose challenges to users with motor disabilities - including the inability to move their limbs, particularly their upper and lower arms, and fingers, due to traumatic damage or congenital problems. In order to meet these challenges, this paper proposes a virtual reality (VR)-based medium to help users with motor disabilities build simple 3D models for architectural design. The concept of operating buttons using head-gaze in the VR environment has been utilised to perform scaling - a 3D object manipulation method - to create simplified building models. Moreover, navigation in the VR space using tilting of the head has been employed with the user seated on a revolving chair, thus eliminating the need for any limbic movement. Unity game engine was used to develop two variations of the VR model with a different button layout for creating simple cuboidal volumes mimicking buildings in the virtual environment. Both variations have been tested with 32 individuals against a specific performance indicator (i.e., task completion time) and self-reported metrics, such as the perception of effort applied and degree of visual clutter, followed by retrospective participant feedback sessions. One of the VR application's variants (i.e., variant 1) produced promising results regarding overall usability and effort demand. This paper also proposes a methodological framework for an AI-based, intelligent, and adaptive VR application interface that caters to the user's abilities and pain points in real-time. In the future, this framework could be instrumental in creating a comprehensive gaze-based VR tool for 3D modelling having multiple functions to help users with motor disabilities.