meshComplement

 Reverse the normal of each face in the mesh.

   [V2, F2] = meshComplement(V, F)

   Example
     [v, f] = createOctahedron;
     meshVolume(v, f)
     ans =
         1.3333
     [v2, f2] = meshComplement(v, f);
     meshVolume(v2, f2)
     ans =
        -1.3333

   See also
     meshes3d, meshVolume

0001 function varargout = meshComplement(varargin)
0002 % Reverse the normal of each face in the mesh.
0003 %
0004 %   [V2, F2] = meshComplement(V, F)
0005 %
0006 %   Example
0007 %     [v, f] = createOctahedron;
0008 %     meshVolume(v, f)
0009 %     ans =
0010 %         1.3333
0011 %     [v2, f2] = meshComplement(v, f);
0012 %     meshVolume(v2, f2)
0013 %     ans =
0014 %        -1.3333
0015 %
0016 %   See also
0017 %     meshes3d, meshVolume
0018  
0019 % ------
0020 % Author: David Legland
0021 % e-mail: david.legland@inrae.fr
0022 % INRAE - BIA Research Unit - BIBS Platform (Nantes)
0023 % Created: 2020-01-22,    using Matlab 9.7.0.1247435 (R2019b) Update 2
0024 % Copyright 2020 INRAE.
0025 
0026 % extract mesh data
0027 mesh = parseMeshData(varargin{:});
0028 faces = mesh.faces;
0029 
0030 % iterate over faces to invert order of vertex indices
0031 if isnumeric(faces)
0032     for i = 1:size(faces, 1)
0033         faces(i,:) = faces(i, end:-1:1);
0034     end
0035 else
0036     for i = 1:size(faces, 1)
0037         faces{i} = faces{i}(end:-1:1);
0038     end
0039 end
0040 
0041 % create new mesh data
0042 varargout = formatMeshOutput(nargout, mesh.vertices, faces);