Research On Automatic Generation Of Tree Based On L System

L system is a theory to simulate the biomorphic structure which proposed by an biologist named Aristid Lindenmayer. It is a kind of basic theory in the field of modeling virtual plant. Trees are indispensable landscape composition in computer simulation of virtual scene. There are many Chinese and foreign scholars are studying on the algorithms to simulate trees efficiently, L system is one of the most famous algorithms. Plant morphology has self-similar rules, which means each independent subsystem of the female system is a miniature of the female system. L system represents the geometry topology structure of plant by string iteration, but the process is very complex and difficult to understand.Usually, if people use L system to construction tree models, firstly they should design corresponding string rules. Due to the different trees graphics corresponding to the different string rules, if people want to obtain ideal trees graphics, they must master L system principle and compile corresponding string rules, which greatly restrict the applications of L system. L system is a bottom-up modeling method to describe the process of plant growth, so the final tree graphic is unpredictable and lack of realism.The study found that, usually the form of main branches is the most important factor to affect the shape of a tree. Therefore this paper proposed a kind of intelligent identification algorithms with reverse thinking. Users don't need to write character rules, just need to sketch a 2d linear sketch which describe the shape of the tree, and fine-tuning some parameters, then the software automatically identify applicable string rules and draw the complex trees graphics quickly. The method is implemented in VC++ environment, the software with some real-time and human-computer interaction.