Procedural authoring of solid models

This thesis investigates the creation, representation, and manipulation of volumetric geometry suitable for computer graphics applications. In order to capture and reproduce the appearance and behavior of many objects, it is necessary to model the internal structures and materials, and how they change over time. However, producing real-world effects with standard surface modeling techniques can be extremely challenging. My key contribution is a concise procedural approach for authoring layered, solid models. Using a simple scripting language, a complete volumetric representation of an object, including its internal structure, can be created from one or more input surfaces, such as scanned polygonal meshes, CAD models or implicit surfaces. Furthermore, the resulting model can be easily modified using sculpting and simulation tools, such as the Finite Element Method or particle systems, which are embedded as operators in the language. Simulation is treated as a modeling tool rather than merely a device for animation, which provides a novel level of abstraction for interacting with simulation environments. I present an implementation of the language using a flexible tetrahedral representation, which I chose because of its advantages for simulation tasks. The language and implementation are demonstrated on a variety of complex examples that were inspired by real-world objects. Thesis Supervisor: Julie Dorsey Title: Professor of Computer Science, Yale University Thesis Supervisor: Leonard McMillan Title: Professor of Computer Science, University of North Carolina, Chapel Hill