三维地形生成

Posted 2021-02-03 wylwyl

三维地形生成的相关代码matlab

 1 function terrain()
 2 n=9;%递归次数
 3 H=2;%设置初始正方形四顶点值
 4 t=0.2;%控制地貌形态
 5 delta=0.01;%初始随机位移偏移量，控制地貌形态
 6 size=2^n+1;
 7 S=zeros(size,size);%设置size*size的初始方阵
 8 S(1,1)=H+sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;%赋初始高度值
 9 S(1,size)=H+sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
10 S(size,1)=H+sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
11 S(size,size)=H+sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
12 x1=1;
13 y1=1;
14 x2=size;
15 y2=size;
16 depth=0;
17 S=fractal(S,x1,y1,x2,y2,depth,t,delta);%调用子函数，传递参数
18 x=1:size;
19 y=1:size;
20 [X,Y]=meshgrid(x,y);
21 hidden off;
22 surf(X,Y,S);
23 Smin=min(min(S));
24 Smax=max(max(S));
25 axis([0 size 0 size Smin Smax]);
26 grid off;
27 %box off
28 colormap(gray);
29 shading interp;
30 %material default;
31 
32 
33 function S=fractal(S,x1,y1,x2,y2,depth,t,delta)%子函数调用，返回矩阵S
34 if round((x2+x1)/2)==(x2+x1)/2
35 S((x1+x2)/2,(y2+y1)/2)=(S(x1,y1)+S(x1,y2)+S(x2,y1)+S(x2,y2))/4+2^(-depth*t)*sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
36 S((x1+x2)/2,y1)=(S(x1,y1)+S(x1,y2))/2+2^(-depth*t)*sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
37 S(x1,(y2+y1)/2)=(S(x1,y1)+S(x2,y2))/2+2^(-depth*t)*sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
38 S((x1+x2)/2,y2)=(S(x2,y1)+S(x2,y2))/2+2^(-depth*t)*sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
39 S(x2,(y2+y1)/2)=(S(x1,y2)+S(x2,y1))/2+2^(-depth*t)*sqrt(1-2^(2*t-2))*normrnd(0,1)*delta;
40 depth=depth+1;
41 S=fractal(S,x1,y1,(x1+x2)/2,(y2+y1)/2,depth,t,delta);%连续四次递归，分别计算上下左右四个正方形的高度，至今还不是很明白它的详细计算过程和规律，如有高手，请赐教
42 S=fractal(S,(x1+x2)/2,y1,x2,(y2+y1)/2,depth,t,delta);
43 S=fractal(S,(x1+x2)/2,(y2+y1)/2,x2,y2,depth,t,delta);
44 S=fractal(S,x1,(y2+y1)/2,(x1+x2)/2,y2,depth,t,delta);
45 end