Explorative Study on Asymmetric Sketch Interactions for Object Retrieval in Virtual Reality

Drawing tools for Virtual Reality (VR) enable users to model 3D designs from within the virtual environment itself. These tools employ sketching and sculpting techniques known from desktop-based interfaces and apply them to hand-based controller interaction. While these techniques allow for mid-air sketching of basic shapes, it remains difficult for users to create detailed and comprehensive 3D models. Our work focuses on supporting the user in designing the virtual environment around them by enhancing sketch-based interfaces with a supporting system for interactive model retrieval. An immersed user can query a database containing detailed 3D models and replace them with the virtual environment through sketching. To understand supportive sketching within a virtual environment, we made an explorative comparison between asymmetric methods of sketch interaction, i.e., 3D mid-air sketching, 2D sketching on a virtual tablet, 2D sketching on a fixed virtual whiteboard, and 2D sketching on a real tablet. Our work shows that different patterns emerge when users interact with 3D sketches rather than 2D sketches to compensate for different results from the retrieval system. In particular, the user adopts strategies when drawing on canvas of different sizes or using a physical device instead of a virtual canvas. While we pose our work as a retrieval problem for 3D models of chairs, our results can be extrapolated to other sketching tasks for virtual environments.