Modeling Method Research Of Ficus Microcarpa Based On Parametric L-system

Tree model is an integral part of a virtual scene, in current field of specific tree modeling, the more modeling research are about economic crops, and less to ornamental plants. Ficus microcarpa tree is a common species in south China, is widely cultivated in many places such as cityscape and landscape scenes. So we choose this kind of tree which has many common characteristic of other species in south China as the modeling object, and research what methods and techniques are needed in the process of modeling. Therefore, a Ficus microcarpa tree model with strong sense of reality can be used in virtual scene of southern Chinese city and park planning. On the other hand, the modeling methods also have reference values for other species tree modeling.According to the existing theories and tools in current field, combined with the requirements of tree modeling, an improved parametric L-system is used to build Banyan model with good appearance.The process of modeling is divided into three steps in this paper. Firstly, to extract the feature data of Ficus microcarpa, then add the data to improved parametric L-system for getting the last string. Secondly, to calculate model coordinates according to the meaning of each character in string. Lastly, rendering the whole model by OpenGL graphics library. First and second step is the main part of modeling process, during the process of constructing production rules of Ficus microcarpa, a method about modular replacement rules is proposed, in this way, partial model changes and substitutions of branch can be achieved. In the step of calculating branch model coordination, Quadratic B-spline interpolation function is introduced to calculate coordination of the branch model which has curved features, in order to achieve smooth transition of branch model. Aerial roots is an important feature of Ficus microcarpa, for modeling this part, we use three different order of Bezier curves combination to simulate aerial roots. In order to optimize the storage structure of data points, a new structure relation to record coupling is proposed, then the amount of data can be reduced.Experiment shows that the Ficus microcarpa model has a small amount of data, and a strong sense of reality. So available tree models can be provided for virtual scene of southern city, also the methods and techniques can be recommendations to other species tree modeling.