outersurf

 outface=outersurf(node,face)

 extract the out-most shell of a complex surface mesh

 author: Qianqian Fang, <q.fang at neu.edu>

 input:
    node:  node coordinates
    face:  surface triangle list

 output:
    outface: the out-most shell of the surface mesh

 -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)

0001 function outface=outersurf(node,face)
0002 %
0003 % outface=outersurf(node,face)
0004 %
0005 % extract the out-most shell of a complex surface mesh
0006 %
0007 % author: Qianqian Fang, <q.fang at neu.edu>
0008 %
0009 % input:
0010 %    node:  node coordinates
0011 %    face:  surface triangle list
0012 %
0013 % output:
0014 %    outface: the out-most shell of the surface mesh
0015 %
0016 % -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
0017 %
0018 
0019 face=face(:,1:3);
0020 
0021 ed=surfedge(face);
0022 if(~isempty(ed))
0023    error('open surface is detected, you have to close it first, consider meshcheckrepair() with meshfix option');
0024 end
0025 
0026 [no,el]=fillsurf(node,face);
0027 
0028 outface=volface(el);
0029 
0030 [no,outface]=removeisolatednode(no,outface);
0031 maxfacenode=max(outface(:));
0032 
0033 [I,J]=ismember(round(no(1:maxfacenode,:)*1e10),round(node*1e10),'rows');
0034 
0035 % if(sum(I)~=maxfacenode)
0036 %     error('mesh tessellation failed');
0037 % end
0038 outface=J(outface);
0039 [ii,jj]=find(outface==0);
0040 outface(ii,:)=[];