Virtual trees are an essential component of many computer generated outdoor scenes. Creation of digital tree models is a difficult and time consuming process requiring specially trained artists and therefore trees are often selected from a library of models. These pregenerated models are expensive, of limited quality and do not suffice when a particular artistic design is required. Moreover, when multiple tree models are combined into scenes, they lack important characteristics of trees that were grown together. My thesis focuses on the development of algorithms and modelling software capable of generating diverse tree forms that are botanically plausible yet easily controlled to meet artistic requirements. I propose a new model of tree growth which enhances the directability and diversity of previous algorithms. A novel multi-touch tablet interface is presented which allows for the free form creation of trees through brushing, pruning and bending of branches into the desired form. Furthermore, I present an algorithm and interface for interactively designing an entire landscape of trees. Neighboring trees exhibit characteristics of being grown together yet they are simulated independently, taking advantage of parallel computing techniques. This ability to easily generate realistic trees and landscapes has applications in the fields of computer graphics and animation, digital landscape design in architectural visualization and computer games.
Steven Longay. Interactive Procedural Modelling of Trees and Landscapes. Ph.D. thesis, University of Calgary, September 2014.
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