freesurfer_surf_separate

 freesurfer_surf_separate - separate left and right hemi-surfaces

 [LH,RH] = freesurfer_surf_separate(FV, NfacesLH, NvertLH, NfacesRH, NvertRH)
 
 It is assumed that FV input is a struct:
 FV.vertices = Nx3, comprising NvertLH followed by NvertRH
 FV.faces = Nx3, comprising NfacesLH followed by NfacesRH

 If NfacesRH and NvertRH are missing, they are assumed to be the remainder
 of FV after extracting the LH.  This assumes that the RH surface was
 concatenated into FV *after* the LH.

 After separating surfaces, try:
 patch('vertices',LH.vertices,'faces',LH.faces,..
       'facecolor',[1 0 0],'edgecolor','none'); light
 
 See also freesurfer_read_surf, freesurfer_surf_combine

0001 function [LH,RH] = freesurfer_surf_separate(FV, NfacesLH, NvertLH, NfacesRH, NvertRH)
0002 
0003 % freesurfer_surf_separate - separate left and right hemi-surfaces
0004 %
0005 % [LH,RH] = freesurfer_surf_separate(FV, NfacesLH, NvertLH, NfacesRH, NvertRH)
0006 %
0007 % It is assumed that FV input is a struct:
0008 % FV.vertices = Nx3, comprising NvertLH followed by NvertRH
0009 % FV.faces = Nx3, comprising NfacesLH followed by NfacesRH
0010 %
0011 % If NfacesRH and NvertRH are missing, they are assumed to be the remainder
0012 % of FV after extracting the LH.  This assumes that the RH surface was
0013 % concatenated into FV *after* the LH.
0014 %
0015 % After separating surfaces, try:
0016 % patch('vertices',LH.vertices,'faces',LH.faces,..
0017 %       'facecolor',[1 0 0],'edgecolor','none'); light
0018 %
0019 % See also freesurfer_read_surf, freesurfer_surf_combine
0020 %
0021 
0022 
0023 % $Revision: 1.1 $ $Date: 2005/08/14 21:24:19 $
0024 
0025 % Copyright (C) 2005  Darren L. Weber
0026 %
0027 % This program is free software; you can redistribute it and/or
0028 % modify it under the terms of the GNU General Public License
0029 % as published by the Free Software Foundation; either version 2
0030 % of the License, or (at your option) any later version.
0031 %
0032 % This program is distributed in the hope that it will be useful,
0033 % but WITHOUT ANY WARRANTY; without even the implied warranty of
0034 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0035 % GNU General Public License for more details.
0036 %
0037 % You should have received a copy of the GNU General Public License
0038 % along with this program; if not, write to the Free Software
0039 % Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
0040 % USA.
0041 
0042 % History:  05/2005, Darren.Weber_at_radiology.ucsf.edu
0043 %
0044 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0045 
0046 ver = '$Revision: 1.1 $ $Date: 2005/08/14 21:24:19 $';
0047 fprintf('FREESURFER_SURF_SEPARATE [v %s]\n\n',ver(11:15));
0048 
0049 if ~exist('FV','var'), 
0050     error('FV undefined');
0051 end
0052 if isempty(FV),
0053     error('FV undefined');
0054 end
0055 
0056 if ~exist('NfacesLH','var'), 
0057     error('NfacesLH undefined');
0058 end
0059 if isempty(NfacesLH),
0060     error('NfacesLH undefined');
0061 end
0062 
0063 if ~exist('NfacesRH','var'),
0064     NfacesRH = length(FV.faces) - NfacesLH
0065 end
0066 if isempty(NfacesRH),
0067     NfacesRH = length(FV.faces) - NfacesLH
0068 end
0069 
0070 if ~exist('NvertLH','var'), 
0071     error('NvertLH undefined');
0072 end
0073 if isempty(NvertLH),
0074     error('NvertLH undefined');
0075 end
0076 
0077 if ~exist('NvertRH','var'),
0078     NvertRH = length(FV.vertices) - NvertLH
0079 end
0080 if isempty(NvertRH),
0081     NvertRH = length(FV.vertices) - NvertLH
0082 end
0083 
0084 if (NvertLH+NvertRH) ~= length(FV.vertices),
0085     error('(NvertLH+NvertRH) ~= length(FV.vertices)');
0086 end
0087 if (NfacesLH+NfacesRH) ~= length(FV.faces),
0088     error('(NfacesLH+NfacesRH) ~= length(FV.faces)');
0089 end
0090 
0091 % separate the vertices
0092 LvertIndex = 1:NvertLH;
0093 RvertIndex = NvertLH+1:NvertLH+NvertRH;
0094 
0095 LH.vertices = FV.vertices(LvertIndex,:);
0096 RH.vertices = FV.vertices(RvertIndex,:);
0097 
0098 % separate the faces
0099 LfaceIndex = 1:NfacesLH;
0100 RfaceIndex = NfacesLH+1:NfacesLH+NfacesRH;
0101 
0102 LH.faces = FV.faces(LfaceIndex,:);
0103 RH.faces = FV.faces(RfaceIndex,:) - length(LH.vertices);
0104 
0105 return