Structural Tree Language (STL): L-System Plant Implementation with Structural Syntax

Abstract

This paper presents a new method for modeling plant forms. Built on L-systems, Structural Tree Language, or STL, is introduced to describe tree shapes in language-based graphics model. Besides traditional L-system primitives (namely Drawing Components in STL), we propose a novel Structural Syntax to enhance the ability of STL, which can be used to describe the outline shapes as well as the exact branching behaviors of trees. In STL, we provide two methods to describe a tree, namely Outline Description and Branch Expansion Description. Outline Description can represent the branch area of a tree in a higher-level mechanism, which specifies only simple rules and shape definitions for trees; whereas Branch Expansion Description provides a lower-lever mechanism, which describes the detailed branch behaviors of trees. We also developed two modules for the user to build his or her trees interactively using these two methods respectively.