function hm=plottetra(node,elem,varargin)
%
% hm=plottetra(node,elem,opt)
%
% plot 3D surface meshes
%
% author: Qianqian Fang <q.fang at neu.edu>
%
% input:
% node: a node coordinate list, 3 columns for x/y/z; if node has a
% 4th column, it will be used to set the color at each node.
% elem: a tetrahedral element list; if elem has a 5th column,
% and the 5th column are all integers, it will be treated
% as labels of sub-domains and display them in different colors.
% if the 5th column contains non-integer values, it will be
% used to map to the color of triangles.
% opt: additional options for a patch object, see plotmesh
%
% output:
% hm: handle or handles (vector) to the plotted surfaces
%
% example:
%
% h=plottetra(node,elem);
% h=plottetra(node,elem,'facealpha',0.5);
%
% -- this function is part of iso2mesh toolbox (http://iso2mesh.sf.net)
%
rngstate = rand ('state');
randseed=hex2dec('623F9A9E'); % "U+623F U+9A9E"
if(isoctavemesh) randseed=randseed+3; end
if(~isempty(getvarfrom({'caller','base'},'ISO2MESH_RANDSEED')))
randseed=getvarfrom({'caller','base'},'ISO2MESH_RANDSEED');
end
rand('state',randseed);
if(~iscell(elem))
if(size(elem,2)>4)
tag=elem(:,5);
types=unique(tag);
hold on;
h=[];
if(all(isinteger(tag)))
for i=1:length(types)
idx=find(tag==types(i));
face=volface(elem(idx,1:4));
if(size(node,2)==3)
h=[h plotsurf(node,face,'facecolor',rand(3,1),varargin{:})];
else
h=[h plotsurf(node,face,varargin{:})];
end
end
else
[face,eid]=volface(elem(:,1:4));
if(size(elem,2)>=5)
h=[h plotsurf(node,face,'FaceVertexCData',tag(eid), varargin{:})];
else
h=[h plotsurf(node,face,varargin{:})];
end
end
else
face=volface(elem(:,1:4));
h=plotsurf(node,face,varargin{:});
end
end
if(~isempty(h))
axis equal;
end
if(~isempty(h) && nargout>=1)
hm=h;
end
rand ('state',rngstate);
