Shapecad: An accessible 3D modelling workflow for the blind and visually-impaired VIa 2.5D shape displays

Abstract

Affordable rapid 3D printing technologies have become key enablers of the Maker Movement by giving individuals the ability to create physical finished products. However, existing computer-aided design (CAD) tools that allow authoring and editing of 3D models are mostly visually reliant and limit access to people with blindness and visual impairment (BVI). Through a series of co-design sessions with three blind users of mixed programming ability, we identify accessibility challenges in existing 3D modelling scripting tools and design interactions to support dynamic feedback of scripts using a 2.5D tactile shape display. With these insights, we implement shapeCAD. Interacting with shapeCAD BVI users are able to leverage the low resolution output from a 2.5D shape display to complement programming of 3D models. shapeCAD allows users to haptically explore and modify existing models, and to author new models. We further validate usability and user experience through an evaluation with five BVI programmers. In a short period of time, novices were able to design a range of new objects. BVI users can bring a valuable perspective to design and it is imperative to increase accessibility in tools that enable this community to also participate as designers.