Constrained illustrative volume deformation

Interactive volume deformation has received a lot of attention recently thanks to the advances of graphics processing units. The ability to transform volumetric objects constitutes an essential tool for generating illustrative visualizations. Previous approaches to this problem have adapted techniques used for surface meshes and applied it to an embedding mesh. This method, however, often results in low quality due to the resolution of the mesh. Other alternatives consider the volume as a homogeneous collection of points, and therefore, cannot simulate physical laws that govern the deformation of different materials. In this paper, we aim at obtaining high-quality illustrations of deformable volumes that mimic physically inspired constraints. For example, although skin and muscle can be illustrated as deforming elastically, bone tissue should move rigidly. Here, we show that we can obtain constrained illustrative deformations with algebraic operations on displacement maps. Through a number of examples, we show that this is a faster alternative to costly physical simulations, with wide applications in computer-aided medical illustration, interactive volume manipulation and data exploration. & 2010 Elsevier Ltd. All rights reserved.