Skeleton And Cut-off Set Based Interactive Three-dimensional Fractal Tree Modeling

Fractal as a new interdisciplinary field, received wide range of academic attention from non-linear field. Fractal provides new concept and method for exploring the complexity of the fractal nature and its inherent objective law. In the field of natural landscap simulation especially the plant simulation, fractal has demonstrated its unique advantages and become one of the hot times.Actually simulating plant by fractal is generating fractal graphics by making use of fractal structure itself. At present, the main methods of simulating plant includes Iterated Function System, L-System, Diffusion Limited Aggregation model and particle system.Basicing the IFS and combining the skeleton-set modeling, this paper discussing the interactive three-dimensional fractal tree modeling techonology.This paper first introduces several expansion IFS such as with aggregation IFS, IFS with parameter, no compress IFS and recurrent IFS and IFS fractal tree modeling techonology based point and line.It provides basises for simulating plant by IFS.Then skeleton-set modeling in computer graphics 3D modeling is introduced which mainly includes the definition, basic principles and concrete function. It provides basises for instead of roundtable modeling with skeleton-set modeling in 3D fractal tree modeling.At last, the advantages and disadvantages of IFS recurrent algorithm based roundtable modeling are analysised. We improved it by using kinds of branch modeling based skeleton-set in order to combine IFS with skeleton-set modeling. And then IFS recurrent algorithm of 3D fractal tree based skeleton-set modeling is advanced and the 3D fractal tree effects generated with those two algorithms are compared. In programming realize part, the main contents contain the computation of 2D affine transformation, the getting way of 3D transformation, the generating of 2D branch modeling, the conversion from 2D branch modeling datas to 3D branch modeling datas and the recurrent generating of 3D fractal tree.This paper put forwards interactive IFS recurrent algorithm of 3D fractal tree based skeleton-set modeling basing of the roundtable modeling. The 3D fractal tree with natural connection and verisimilitude form, which is abtained basing 3D tree modeling with complexity and sense of reality generating from simple 2D hand-drawn graphics with feeling of unreality. The IFS recurrent algorithm of 3D fractal tree based skeleton-set modeling overcomes some disadvantages based roundtable modeling such as single and fixed type, modeling data with the same to affine transformation, the effect of stiffness etc. And it provides new method for 3D fractal tree modeling research and has significant application value in the field of natural scene simulating, animation, virtual reality etc.