The Digital Sandbox: Integrating Design and Analysis in a New Digital Earth-Forming Tool

by Rob Harris

Chairperson of the Supervisory Committee:
Professor Iain Robertson

2001

The goal of this thesis is to provide better support for digital earth-forming by designing and building a computational tool – the Digital Sandbox. It is motivated by the assertion that, although the integration of design and analysis tasks is crucial to the success of earth-forming projects, the ability of designers to do so is limited by existing tools. To address this concern, the Digital Sandbox was designed as a proof-of-concept tool that integrates design and analysis into a single work environment. The system uses a gesture-based interface to enable a user to design a landform and simultaneously analyze patterns of stormwater flow over the landform. The Digital Sandbox was designed and implemented using an object-oriented approach. Software classes represent the objects used in traditional, physical sandboxes and encapsulate the attributes and behaviors of the real-world objects they imitate in order to compute a stormwater accumulation model. The resulting system enables a designer to sculpt a digital mesh, add trees and buildings to the mesh, and run a simple stormwater accumulation model to predict flow paths over the surface of the mesh – all using hand gestures in space. The system has a number of limitations. Full and unconstrained gesture is impossible, and the designer is limited to a predetermined number of gestures. As a result, the model-building process is not as sophisticated as it could be. The stormwater accumulation model is highly simplified, and its parameters and variables can not be specified by the user. Despite these limitations, the Digital Sandbox meets its goal of integrating design and analysis tasks in a single computational environment, while more closely approximating the methods used by designers when working in traditional, physical sandboxes.