Volumetric ablation rendering

In this paper, we propose a physically-based method for simulating the process of ablation on volumetric models. We demonstrate the visual effect of ablative processes, such as a beam of heat emitted from a blow torch or a pencil of sand expelled from a sandblaster. Users are able to control ablative properties, such as energy propagation, absorption, and material evaporation, via a simple transfer function interface, while the effect of different beam shapes can be modeled by ways of weighting functions. Continuous evaporation of material to expose interior object features can eliminate smooth object boundary layers required for good gradient estimation. To prevent this adverse effect, our method leaves the original volume intact and instead operates on a smooth energy volume. The renderer then uses the energy volume to determine the current, smooth object boundaries, for the opacity and gradient calculations, while the original volume provides the visual material properties, such as color and shading coefficients.