Simulation Of Natural Scene With Fractal Geometry

Simulation of natural scene has been a hotspot in the field of computer graphics. With so many scenes included, nature often shows its self-similarity in common. An important mathematical implement, fractal geometry, characterizes this kind of feature perfectly. Fractal method has versatile representations. Choices between these forms should be according as practical need.Modeling and visualization of plants, which is one offset of simulation of natural scene, took the first place in the research about this paper. Representative researches achievements about this field were introduced briefly and respectively. They may be classified into two algorithmic models: morphogenesis model and visualization model, for the sake of facility of comprehension. The former is responsible for generating a plant's topology. The latter, for visualization of those such as branch bending in flexibility, plant organs such as flower and fruit, plants cluster, phototropism, variability by seasons.Simulating broadleaf, as the research background of this paper, related to many key techniques included custom-made L-system, branches bending and ramifications, mighty limbs, leaves distribution. They are also being key techniques in computer simulation of other plants. First, L-system was used as a plant topology generator, and it had been proved to having the fractal feature. This L-system has many features: brief definition, high efficiency, rationality and definite randomicity. Second, the result string of L-system was translated by means of tree-type data structure for the good of showing branch thickness. Each node of this kind of data structure described a segment from the base of the tree or an arbitrary joint to a tree top. And it was extracted from the result string of L-system strictly. This kind of data structure coincides with status space tree searched in blindness. The only difference between them is the strategies they took. Had no use for searching, data structure in this article was used to analyze the existing string only. Third, multi-splines and their connections were also used in simulating branches bending and ramifications. Bezier curves were selected to take on this task in this research. They joined with 0-rank continuum and their angles at these ramifications must be restricted within reasonablevalues. Finally, leaves must be distributed along the branches in certain probabilities conformed to some orders of nature in simulating leaves. Two Simple and optional leaves forms were presented in this paper.This paper made plant simulation as emphasis, and it gave attention to both modeling many other natural scenes. The graphics library Direct3D is used in simulation and realization.