function [node,elem,face]=surf2mesh(v,f,p0,p1,keepratio,maxvol,regions,holes,forcebox,method,cmdopt)
%
% [node,elem,face]=surf2mesh(v,f,p0,p1,keepratio,maxvol,regions,holes,forcebox)
%
% create quality volumetric mesh from isosurface patches
%
% author: Qianqian Fang, <q.fang at neu.edu>
% date: 2007/11/24
%
% input parameters:
% v: input, isosurface node list, dimension (nn,3)
% if v has 4 columns, the last column specifies mesh density near each node
% f: input, isosurface face element list, dimension (be,3)
% p0: input, coordinates of one corner of the bounding box, p0=[x0 y0 z0]
% p1: input, coordinates of the other corner of the bounding box, p1=[x1 y1 z1]
% keepratio: input, percentage of elements being kept after the simplification
% maxvol: input, maximum tetrahedra element volume
% regions: list of regions, specifying by an internal point for each region
% holes: list of holes, similar to regions
% forcebox: 1: add bounding box, 0: automatic
%
% outputs:
% node: output, node coordinates of the tetrahedral mesh
% elem: output, element list of the tetrahedral mesh
% face: output, mesh surface element list of the tetrahedral mesh
% the last column denotes the boundary ID
%
% -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
%
fprintf(1,'generating tetrahedral mesh from closed surfaces ...\n');
if(nargin<10)
method = 'tetgen';
end
exesuff=getexeext;
exesuff=fallbackexeext(exesuff,method);
if(keepratio>1 || keepratio<0)
warn(['The "keepratio" parameter is required to be between 0 and 1. '...
'Your input is out of this range. surf2mesh will not perform '...
'simplification. Please double check to correct this.']);
end
% first, resample the surface mesh with cgal
if(keepratio<1-1e-9 && ~iscell(f))
fprintf(1,'resampling surface mesh ...\n');
[no,el]=meshresample(v(:,1:3),f(:,1:3),keepratio);
el=unique(sort(el,2),'rows');
% then smooth the resampled surface mesh (Laplace smoothing)
%% edges=surfedge(el); % disable on 12/05/08, very slow on octave
%% mask=zeros(size(no,1),1);
%% mask(unique(edges(:)))=1; % =1 for edge nodes, =0 otherwise
%[conn,connnum,count]=meshconn(el,length(no));
%no=smoothsurf(no,mask,conn,2);
% remove end elements (all nodes are edge nodes)
%el=delendelem(el,mask);
else
no=v;
el=f;
end
if(nargin==6)
regions=[];
holes=[];
elseif(nargin==7)
holes=[];
end
if(size(regions,2)>=4 && ~isempty(maxvol))
warning('you specified both maxvol and the region based volume constraint,the maxvol setting will be ignored');
maxvol=[];
end
dobbx=0;
if(nargin>=9)
dobbx=forcebox;
end
% dump surface mesh to .poly file format
if(~iscell(el) && ~isempty(no) && ~isempty(el))
saveoff(no(:,1:3),el(:,1:3),mwpath('post_vmesh.off'));
end
deletemeshfile(mwpath('post_vmesh.mtr'));
savesurfpoly(no,el,holes,regions,p0,p1,mwpath('post_vmesh.poly'),dobbx);
moreopt='';
if(size(no,2)==4)
moreopt=[moreopt ' -m '];
end
% call tetgen to create volumetric mesh
deletemeshfile(mwpath('post_vmesh.1.*'));
fprintf(1,'creating volumetric mesh from a surface mesh ...\n');
if(nargin<11)
try
cmdopt=evalin('caller','ISO2MESH_TETGENOPT');
catch
try
cmdopt=evalin('base','ISO2MESH_TETGENOPT');
catch
cmdopt='';
end
end
end
if(isempty(cmdopt))
[status, cmdout]=system([' "' mcpath(method,exesuff) '" -A -q1.414a' num2str(maxvol) ' ' moreopt ' "' mwpath('post_vmesh.poly') '"']);
else
[status, cmdout]=system([' "' mcpath(method,exesuff) '" ' cmdopt ' "' mwpath('post_vmesh.poly') '"']);
end
if(status~=0)
error(sprintf('Tetgen command failed'));
end
% read in the generated mesh
[node,elem,face]=readtetgen(mwpath('post_vmesh.1'));
fprintf(1,'volume mesh generation is complete\n');