3D-environment generation using volume-based techniques

Abstract

Land maps is a major contributor towards the perception of virtual environments. Many procedural terrain generation techniques employ height maps (stored as 2D images) in order to generate land surface, however these limit the features which can be generated. This project addresses the limitations imposed by height maps, and allows for the generation of features consisting of overlapping land features, including caves, arches and subterranean areas. A volumetric data structure, termed as the voxel space, is used to represent the generated terrain. A voxel space can be easily visualized as a cubic space partitioned into smaller, equal-sized cubes ( voxels), which define an environment. We propose a number of sculpting techniques which operate on this space, carving and modeling it, to form terrains and landscapes with unique features. Specifically, we propose two classes of sculpting techniques: a class based on regular expressions and another based on three-dimensional surface modeling functions. Both technique classes are highly parameterizable. In the first case, a specific alphabet and a set of syntactic structures are used to construct regular expressions, which once evaluated, generate a string whose characters represent some operation on the voxel space. Surface modeling functions define a partitioning surface on the voxel space; one of the resultant half-spaces is used to perform boolean subtraction on the voxel space. This technique allows for substantial customization through input arguments. Sculpting techniques operate in a pipeline fashion on the voxel space to generate the final result. Several case studies have demonstrated that the best results are obtained when ever both sculpting techniques are used together. Using only one technique has proven difficult to generate certain features. The surface modelling functions are best used to generate base surface features, while regular expressions are best used to drill areas, such as caves or tunnels, inside a landmass.