[x,y,z]=sphere;
%matlab中sphere函数zd [X,Y,Z]=sphere(30)，其中参数30表示球面沿着经度、纬度方向被分成的面片数。
patches=surf2patch(x,y,z,z);%将曲面数据转化为块数据
Ssun=1;%太阳半径=1
Searth=0.3;%地球半径=0.3
Smoon=0.1;%月亮半径=0.1
Res=4;
Rme=1;
alpha=0; %α
beta=0; %β
theta=0; %θ
step_a=0.1; %a的步长
step_b=0.2; %b的步长
step_t=0.05; %c的步长
Csun=[0,0,0]; %太阳的坐标
h=figure; %窗口
set(h,‘toolbar’,‘none’,‘menubar’,‘none’,‘numbertitle’,‘off’) %创建窗口图
while 1==1 %旋转绕圈
clf %清除窗口图像
Cx=Rescos(alpha); %
Cy=Ressin(alpha); %
Cz=0;
Cearth=[Cx,Cy,Cz]; %地球运行轨迹
u=(Csun-Cearth)/norm(Csun-Cearth);
v=[0,0,1];
w=cross(u,v); %cross向量叉乘
T=inv([u(1),u(2),u(3),0;v(1),v(2),v(3),0;w(1),w(2),w(3),0;0,0,0,1][1,0,0,-Cx;0,1,0,-Cy;0,0,1,-Cz;0,0,0,1]); %inv矩阵求逆
Cmoon=T[Rmecos(beta);Rmesin(beta);0;1]; %月亮周期自转 41矩阵
%绘制太阳
patches_sun=patches; %patches给某个区域填充颜色
Rz=[cos(theta) -sin(theta) 0;sin(theta) cos(theta) 0;0 0 1]; %Rz矩阵为33
[len,t]=size(patches.vertices);
for i=1:len
P=Rz*[patches.vertices(i,1);patches.vertices(i,2);patches.vertices(i,3)];
patches_sun.vertices(i,1)=P(1);
patches_sun.vertices(i,2)=P(2);
patches_sun.vertices(i,3)=P(3);
end
patch(patches_sun),shading faceted,hold on %shading是用来处理色彩效果的 shading faceted是默认模式，hold on 你在当前图的轴（坐标系）中画了一幅图，再画另一幅图时，原来的图还在，与新图共存，都看得到
%绘制月亮
patches_moon=patches;
[len,t]=size(patches.vertices);
for i=1:len
P=Rz*[patches.vertices(i,1)*Smoon;patches.vertices(i,2)*Smoon;patches.vertices(i,3)Smoon]+[Cmoon(1);Cmoon(2);Cmoon(3)];
patches_moon.vertices(i,1)=P(1);
patches_moon.vertices(i,2)=P(2);
patches_moon.vertices(i,3)=P(3);
end
patch(patches_moon),shading faceted %shading是用来处理色彩效果的 shading faceted是默认模式
%绘制地球
patches_earth=patches;
[len,t]=size(patches.vertices);
for i=1:len
P=Rz[patches.vertices(i,1)*Searth;patches.vertices(i,2)*Searth;patches.vertices(i,3)*Searth]+[Cx;Cy;Cz];
patches_earth.vertices(i,1)=P(1);
patches_earth.vertices(i,2)=P(2);
patches_earth.vertices(i,3)=P(3);
end
patch(patches_earth),shading faceted %shading是用来处理色彩效果的 shading faceted是默认模式
daspect([1,1,1]); %设置坐标轴的长：宽：高 =1
campos([5,5,2]),camtarget([0,0,0]),camup([0,0,1]),camva(30),
axis off
pause(0.1) % pause(a)暂停a秒后再执行
beta=beta+step_b; %β=β+b步长alpha=alpha+step_a; %α=α+a步长theta=theta+step_t; % θ=θ+t步长
end
