meshreorient

 [newelem, evol]=meshreorient(node,elem)

 reorder nodes in a surface or tetrahedral mesh to ensure all
 elements are oriented consistently

 author: Qianqian Fang, <q.fang at neu.edu>
 date: 2010/05/05

 input:
    node: list of nodes
    elem: list of elements (each row are indices of nodes of each element)

 output:
    newelem: the element list with consistent ordering
    evol: the signed element volume before reorientation

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

0001 function [newelem, evol]=meshreorient(node,elem)
0002 %
0003 % [newelem, evol]=meshreorient(node,elem)
0004 %
0005 % reorder nodes in a surface or tetrahedral mesh to ensure all
0006 % elements are oriented consistently
0007 %
0008 % author: Qianqian Fang, <q.fang at neu.edu>
0009 % date: 2010/05/05
0010 %
0011 % input:
0012 %    node: list of nodes
0013 %    elem: list of elements (each row are indices of nodes of each element)
0014 %
0015 % output:
0016 %    newelem: the element list with consistent ordering
0017 %    evol: the signed element volume before reorientation
0018 %
0019 % -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
0020 %
0021 
0022 % calculate the canonical volume of the element (can be a 2D or 3D)
0023 evol=elemvolume(node,elem,'signed');
0024 
0025 % make sure all elements are positive in volume
0026 idx=find(evol<0);
0027 elem(idx,[end-1,end])=elem(idx,[end,end-1]);
0028 newelem=elem;