GPU Based Liquids and Surface Effects - Cauterization and blood flow for surgical simulation

Abstract

Virtual surgery is a didactic tool used in order to train surgeons without risk to people or animals. To achieve sufficient realism, these simulations require surface effects such as burn marks from cauterization and bleeding from damaged vessels. We propose efficient methods for generating such surface effects using the Graphics Processing Unit. For each of the two effects, multiple solutions are proposed and discussed. The chosen options are then motivated and explained in detail. Primary focus is placed on simulation of fluid dynamics using particle systems. In order to simulate cauterization, we propose a GPU-based method using floating-point textures to store temperature and tissue decay. These decay values are used to interpolate between textures which represent different degrees of tissue damage. Efficient approximation of the distance between surfaces and operating instruments is achieved using a three-dimensional distance-field. Blood flow is simulated on the GPU using a two-dimensional form of Smoothed Particle Hydrodynamics, projected into the texture-space of a mesh. Linked lists are used for efficient representation of hash buckets. We find that our GPU-based version performs significantly better than a CPU-based alternative. In the results section, interactive frame rates are achieved with over 100,000 particles in the system.