3-dof Haptic Rendering

1. Introduction Haptic rendering enables a user to touch, feel, and manipulate virtual objects through a haptic interface (see Figure 1). The field has shown a significant expansion during the last decade. Since the publication of earlier review papers (Salisbury and Srinivasan, 1997; Srinivasan and Basdogan, 1997), new rendering techniques and several new applications have emerged (see the more recent reviews in Basdogan and Srinivasan, 2002, Salisbury et al, 2004, and Laycock and Day, 2007). The applications now cover a wide range of fields including medicine (surgical simulation, tele-medicine, haptic user interfaces for blind persons, rehabilitation for patients with neurological disorders, dental medicine) art and entertainment (3D painting, character animation, digital sculpting, virtual museums), computer-aided product design (free-form modeling, assembly and disassembly including insertion and removal of parts), scientific visualization (geophysical data analysis, molecular simulation, flow visualization), and robotics (path planning, micro/nano tele-manipulation). This chapter will primarily focus on the fundamental concepts of haptic rendering with some discussion of implementation details. In particular, we will focus on the haptic interactions of a single point (i.e. Haptic Interface Point-HIP-in Figure 1) with a 3D object in virtual environments. This corresponds to feeling and exploring the same object through a stylus in real world. This chapter is entitled 3-dof haptic rendering to differentiate it from 6-dof rendering which involves object-object interaction and is covered in the other parts of this book.