Blended Physical-Digital Kinesthetic Feedback for Mixed Reality-Based Conceptual Design-In-Context

In this paper, we investigate blended physical-digital kinesthetic feedback (or blended haptics in short) as a means for controlled three-dimensional design ideation in mixed reality (MR) environments. We define blended haptics as a spatial interaction wherein a physical object (e.g. a 3D printed human head) provides a specific design context for a user to generate ideas through physical manipulation of and on the object (e.g. drawing a digital sketch of a helmet) in the virtual environment. Using 3D wire-frame modeling as a concrete digital prototyping context, we investigate this idea of blended haptics in terms of how it supports design cognition specifically in spatial user interfaces. For this, we implemented a modeling tool as an experimental setup that allows a user to directly create curve-networks (wire-frame models) on a physical object (i.e. a contextual proxy) with one hand while simultaneously controlling the object with the other hand using a tracked turn-table. The key idea is that the user can simultaneously experience kinesthetic feedback from both the physical objects as well as the digital wire-frame models. To systematically investigate our approach, we conducted a comparative user evaluation of conceptual design tasks performed by two groups of users, one with the blended haptics (e.g. physical head and digital helmet) and the other with purely digital haptic feedback (e.g. digital head and digital helmet). Our study shows that blended haptics required less physical effort in the design task and resulted in concepts with higher novelty score as compared to using purely digital haptic feedback.