Quality control tools for interactive rendering of 3D triangle meshes

Abstract

In this dissertation we explore methods of quality control of untextured polygonal models. The tools presented build, evaluate and improve on the field of multiresolution analysis through decimation. We evaluate the quality of models generated through various simplification algorithms to develop efficient measures of image quality. We develop an application for selective, progressive and view-dependent refinement, suitable for browsing 3D models on the internet. Existing work in continuous level-of-detail is extended to allow for faster interpolation between LOD sequences and we present a new LOD control mechanism for maintaining a constant polygon count. We present a generic framework generates multiresolution models through simplification. This allows for the comparison of surface compression methods under the same conditions, and to determine the performance of surface quality measures based on these results. These measures of surface quality are evaluated with both image and model based criteria. We find that the declining volume of a simplified object is a good method of predicting view-independent image quality. Using our generic framework, we extend two applications which can be used to improve rendering performance in a virtual environment. We develop a new selective refinement application which refines only a desired region of the model, suitable for online model browsing. This method provides substantial space saving due to a more compact representation of the simplification hierarchy, and also provides optimisations for use with a client/server model. A novel method of defining smooth mappings between different resolution versions of a model (called continuous level-of-detail) is also defined. This technique greatly improves rendering performance of these models by employing commonly available programmable graphics hardware. We also present a method of controlling the number of polygons in large scenes, which is capable of predictively maintaining a constant frame rate by guaranteeing a polygon budget.