Dynamic layering system for real-time interaction between entities and terrain

Abstract

This thesis describes a method which deals with terrain deformation and excavation in a virtual environment. Research into the subject has generally focussed on representation of the surface of the terrain, with methods based on triangle meshes with level of detail to voxel based surfaces, sometimes with deformation rules based on physics. However, most do not take sub-surface areas of terrain into account, nor do they consider multi-user interaction. The method we present deals with terrain deformation as manipulation of volumetric data, with emphasis on retaining data describing the subsurface parts of the terrain. Manipulation of the data is caused by interactions between multiple entities and the terrain, where each entity is directed by a user within a multiuser network environment. Experiments which were run to measure the performance of our methodology have shown that it is able to handle interactions at a lower than real-time rate, with its data structure best suited for scenarios which cause contiguous changes, such as a ball rolling through snow, as opposed to interactions causing highly random changes, which cause the data structure to grow rapidly. Experiments have also shown that client-side calculation of changes is possible, but it remains unclear if this is preferable to server-side calculation in terms of absolute calculation time.