把STL文件ACSII格式读入matlab

function [fout, vout, cout] = ReadSTLACSII(filename)


fid=fopen(filename, 'r');
if fid == -1 
    error('文件打开错误！.')
end


%读取文件头，STL文件第一行是文件名
File_name = sscanf(fgetl(fid), '%*s %s');  %CAD object name, if needed.


%定义变量
vnum=0;       %Vertex number counter.
report_num=0; %Report the status as we go.
STLvcolor = 0;
STLxyz=0;


%开始读整个文件，直到结束符为止
while feof(fid) == 0                    % test for end of file, if not then do stuff
    tline = fgetl(fid);                 % reads a line of data from file.
    fword = sscanf(tline, '%s');       % make the line a character string


%检查颜色
if strncmpi(fword, 'facet normal',12) == 1;    % Checking if a "C"olor line, as "C" is 1st char.
       STLvcolor = sscanf(tline, '%*s %f %f %f'); % & if a C, get the RGB color data of the face.   % we "*s" skip the name "color" and get the data.      
end                                            % Keep this color, until the next color is used.


%检查坐标
if strncmpi(fword, 'vertex',6) == 1;    % Checking if a "V"ertex line, as "V" is 1st char.
       STLxyz= sscanf(tline, '%*s %lf %lf %lf'); % & if a V, get the XYZ data of it.
          vnum = vnum + 1; 
end


%检查坐标是否增加
if  vnum~=report_num
     report_num=vnum;
       v(:,vnum)=STLxyz;
       c(:,vnum) = STLvcolor;              % A color for each vertex, which will color the 
       if mod(report_num,249)==0;
           disp(sprintf('Reading vertix num: %d.',vnum));
       end
end
                                                             
end


%关闭文件
fclose(fid);




%   Build face list; The vertices are in order, so just number them.
fnum = vnum/3;      %Number of faces, vnum is number of vertices.  STL is triangles.
flist = 1:vnum;     %Face list of vertices, all in order.
F = reshape(flist, 3,fnum); %Make a "3 by fnum" matrix of face list data.
%
%   Return the faces and vertexs.
%
fout = F';  %Orients the array for direct use in patch.
vout = v';  % "
cout = c';




end