CoPadSAR: A Spatial Augmented Reality Interaction Approach for Collaborative Design via Pad‐Based Cross‐Device Interaction

Augmented reality (AR) is a technology that superimposes digital information onto the real world. As one of the three major forms of AR, spatial augmented reality (SAR) projects virtual content into public spaces, making it accessible to collaborators. Due to its shared large display area, SAR has significant potential for application in collaborative design. However, existing SAR interaction methods may suffer from inefficiencies and poor collaborative experiences. To address this issue, CoPadSAR, a Pad‐based cross‐device interaction method, is proposed. It can map 2D operations from each Pad onto 3D objects within the SAR environment, allowing users to collaborate using multiple Pads. Moreover, a prototype is presented that supports collaborative painting, annotation, and object creation. Furthermore, a comparative study involving 40 participants (20 pairs) is conducted. The results indicate CoPadSAR reveals better group performance than controller‐based, gesture, and tangible interactions. It has greater usability and provides a better collaborative experience. The interviews further confirm the user preference for it. This study contributes to expanding the application of SAR in collaborative design.