A haptic interface for creating smooth 3D curves with varying line weight

We present a two-handed haptic interface for free-form 3D modeling in virtual reality that provides the artist with the ability to input controlled, smooth, 3D curves and to naturally vary line weight while drawing a 3D mark. As free-form modeling tools are used to tackle more and more complicated subjects, such as scientific illustrations [Keefe et al. 2005], artists are finding that they need more control over their modeling tools. This interface is an attempt to provide artists with more control in specifying both 3D form and style. The modeling medium we use for this project is something like virtual wire sculpture: 3D models made of thin ribbon-like curves. These curves are typically viewed with a stereo virtual reality display and they exist in a three-dimensional space, so they can be viewed from any direction (three views of an example model are shown in Figure 1).