Interactive global and local deformations for virtual clay

Making virtual modeling as easy and intuitive as real-clay manipulation is still an unsolved problem. This paper takes a step in this direction: in addition to offering standard features such as addition and removal of material, it uses a new real-time plasticity model to let the user apply local and global deformations such as those made in real clay by pressing with a finger or bending a sculpture with one hands. Although not completely physically accurate, the model exhibits several important features of real clay, namely plasticity; mass conservation, and surface tension effects. These features make the model intuitive, since the user obtains the shapes he expects, as demonstrated by our results.