随机生长模型，用以模拟多孔介质的孔隙结构，根据不同参数，主要是孔隙率的改变，生成不同孔结构-porous medium simulation

随机四参数构建多孔介质的三维模型，参数可灵活设置，程序算法精简-Construction of three-dimensional model of porous media random four parameters, the parameters can be flexibly set, streamlined program algorithm