1## Copyright (C) 2021 David Legland
2## All rights reserved.
3##
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5## modification, are permitted provided that the following conditions are met:
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27
28function [refMesh, distListIters, refVerticesIters] = averageMesh(meshList, varargin)
29% Compute average mesh from a list of meshes.
30%
31%   AVG = averageMesh(MESHLIST)
32%
33%   Example
34%   averageMesh
35%
36%   See also
37%     meshes3d
38
39% ------
40% Author: David Legland
41% e-mail: david.legland@inrae.fr
42% INRAE - BIA Research Unit - BIBS Platform (Nantes)
43% Created: 2020-01-31,    using Matlab 9.7.0.1247435 (R2019b) Update 2
44% Copyright 2020 INRAE.
45
46
47%% Parse input values
48
49% default values
50nIters = 10;
51verbose = false;
52
53% parse input arguments
54while length(varargin) > 1
55    name = varargin{1};
56    if ~ischar(name)
57        error('require parameter name-value pairs');
58    end
59
60    if strcmpi(name, 'verbose')
61        verbose = varargin{2};
62    elseif strcmpi(name, 'nIters')
63        nIters = varargin{2};
64    else
65        error(['Unknown parameter name: ' name]);
66    end
67    varargin(1:2) = [];
68end
69
70
71%% Initialisations
72
73nMeshes = length(meshList);
74
75% initialize kd-trees to accelerate nearest-neighbor searches
76treeList = cell(nMeshes, 1);
77for iMesh = 1:nMeshes
78    treeList{iMesh} = KDTreeSearcher(meshList{iMesh}.vertices);
79end
80
81% choose arbitrary initial mesh
82refMesh = struct('vertices', meshList{1}.vertices, 'faces', meshList{1}.faces);
83
84refVerticesIters = cell(1, nIters);
85distListIters = cell(1, nIters);
86
87
88%% Main iteration
89
90for iIter = 1:nIters
91    if verbose
92        fprintf('iter %d/%d\n', iIter, nIters);
93    end
94    refMesh = smoothMesh(refMesh);
95
96    % create new array for average vertices
97    newVerts = zeros(size(refMesh.vertices));
98    distList = zeros(size(refMesh.vertices, 1), 1);
99
100    % iterate over all meshes
101    for iMesh = 1:nMeshes
102        if verbose
103            fprintf('    mesh %d/%d\n', iMesh, nMeshes);
104        end
105
106%         mesh = meshList{iMesh};
107        inds = knnsearch(treeList{iMesh}, refMesh.vertices);
108
109%         closest = mesh.vertices(inds,:);
110        closest = treeList{iMesh}.X(inds,:);
111        newVerts = newVerts + closest;
112        distList = distList + sum((closest - refMesh.vertices).^2, 2);
113    end
114
115    % update new vertices
116    newVerts = newVerts / nMeshes;
117    refVerticesIters{iIter} = newVerts;
118    refMesh.vertices = newVerts;
119
120    % keep list of distances
121    distList = sqrt(distList / nMeshes);
122    distListIters{iIter} = distList;
123end
124
125
126% figure; drawMesh(refMesh, 'lineStyle', 'none', 'faceColor', [.5 .5 .5])
127% axis equal; view(3); hold on; axis([-2.5 2.5 -2 2 -3.5 3.5]); light;
128% lighting gouraud
129% title('Average mesh');
130% print(gcf, 'averageMesh_initial.png', '-dpng');
131
132