UBC Theses and Dissertations
Ribbon drawing in VR : brushes and applications Rosales Ruiz, Enrique Alberto
Virtual reality drawing applications let users draw 3D shapes using brushes that form ribbon-shaped, or ruled-surface, strokes. Each ribbon is uniquely defined by its user-specified ruling length, path, and the ruling directions at each point along this path. A collection of these virtual ribbons with proper normal orientations can communicate complex surfaces; thus, artists frequently describe their envisioned 3D surfaces by drawing dense brush strokes that cover the surface of the intended shapes. In this thesis, we analyze these ribbon brushes, and propose ways to expand the scope of their applications and improve their usability. Currently, the practical use of these drawings is limited since most geometry processing algorithms and downstream applications such as 3D printing require manifold meshes. Furthermore, existing brushes use the trajectory of a handheld controller in 3D space as the ribbon path, and compute the ruling directions using a fixed mapping from a specific controller coordinate-frame axis. This fixed mapping requires users to rotate the controller and thus their wrists to change ribbon normal or ruling directions, which requires substantial physical effort to draw even medium complexity ribbons. As people have limited ability to rotate their wrists continuously, the range of ribbon geometries they can comfortably draw with these brushes is limited. We solve these problems by first developing SurfaceBrush, a surfacing method that converts such VR drawings into user-intended manifold free-form 3D surfaces. We then present AdaptiBrush, a ribbon brush system that dramatically extends the space of ribbon geometries users can comfortably draw while enabling them to accurately predict the ribbon shape that a given hand motion produces. Our work expands the range of applications of VR drawing and makes VR drawing a viable alternative to 3D modeling for inexperienced users.
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Attribution-NonCommercial-NoDerivatives 4.0 International