Volume haptic rendering with dynamically extracted isosurface

Haptic interfaces offer an intuitive way to interact with and manipulate 3D data, and may simplify the interpretation of visual information. This work proposes an algorithm to provide haptic feedback directly from volumetric data sets, as an aid to regular visualization. The haptic rendering algorithm lets the user perceive isosurfaces in the volumetric data, and it relies on several design features that ensure a robust and efficient rendering. Robustness is derived from existing proxy-based methods. The presented algorithm adds a novel continuous collision detection based on dynamic extraction of isosurfaces in tetrahedral meshes in order to avoid fall-through of surfaces. The isosurface is extracted dynamically in a local manner, hence there is no need to construct and store the full isosurface, thereby reducing both computational cost and storage at the same time. Isosurfaces are defined by interpolating a density field on tetrahedral meshes. The use of tetrahedral meshes guarantees continuity and watertightness of the isosurface, and it also enables smooth transitions between isosurface values.