The Design And Implementation Of 3D Three Simulate System Based On L-System

Trees are an important part of the natural scene, and the simulation algorithm of tree is always a hot research issue. The shape of a tree is the interaction consequence of tree's physiology discipline and the environment. To simulate a lifelike tree, not only the shape of the tree should be accurately modeling and rendering, but also the influence of the environment to the tree characteristics should be regarded. It has important practical significance and broad application prospect, that description the shape of a tree quantitatively and visually by using the technology and method of computer graphics and virtual reality, developing the corresponding software and interactive platform, and simulating a more lifelike 3D tree through the method of visual experience and human-machine interaction.Recently, the simulation of 3D trees gets many notable achievements. But as the trees'complex shape and great varieties, it is difficult to modeling, memory and rendering of them. The existing simulation methods are lack of universality and interactivity, can't meet to the require of the diverse of trees, and the lifelike of trees remains should be strengthened; on the other hand, the over ground parts and the underground parts of trees are not as a whole in the existing method.L system is a classical method of simulate plants, and the basic algorithm of L system is mainly introduced in this paper. Through researching and analysis the existing algorithm of simulate trees, an improved algorithm based on 3D branching model is proposed, in which algorithm, firstly, the structure of trees is divided into four levels including leaf, leaf arrangement, trunk and root, and building the level model of tree according to the self similar principle of trees, secondly, the influence of gravity to the shape of trees is regarded in the modeling, and according to the material principle, the simulation of the bending branch is realized, that each branch is divided into few segments, and each segment is seen as a cantilever beam. The random parameter L system is used in the tree modeling in this paper, which solves the problem of universality of algorithm and the diversity of the trees shape. In order to make the 3D tree simulate system owning greater flexibility, the related attributes which influence the shape of trees are extracted to corresponding parameters in the improved algorithm. To freely modify and simulate the shape of tree, users only need to set corresponding parameters when using the system, which realize the function of that the shape of the trees can be optionally controlled by the requirement of users. As programming is cockamamie, the execute efficiency is low, and the interactive is poor when realizing trees by using the traditional L system, Java combine with the virtual reality modeling language(X3D) is choose as the programming language to realize the algorithm of the interactive L system. On the other hand, in order to facilitate the users and share the system better, Struts2 framework is choose to implement the interface of the system in this paper, and the default values of the parameters of the common trees is stetted.The simulate result shows that, with constructing trees model by using the improved algorithm, the over ground parts and underground parts of trees can be well combine, the space characteristics, phototaxis and geotropism of trees can be well performance, and the shape of trees is more lifelike. With this system, the requirement of the tree diverse is meted, and making it possible that users interact with the system freely.