1 // This file is part of libigl, a simple c++ geometry processing library.
2 //
3 // Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
4 //
5 // This Source Code Form is subject to the terms of the Mozilla Public License
6 // v. 2.0. If a copy of the MPL was not distributed with this file, You can
7 // obtain one at http://mozilla.org/MPL/2.0/.
8 #include "covariance_scatter_matrix.h"
9 #include "arap_linear_block.h"
10 #include "cotmatrix.h"
11 #include "diag.h"
12 #include "sum.h"
13 #include "edges.h"
14 #include "verbose.h"
15 #include "cat.h"
16 #include "PI.h"
17
covariance_scatter_matrix(const Eigen::MatrixXd & V,const Eigen::MatrixXi & F,const ARAPEnergyType energy,Eigen::SparseMatrix<double> & CSM)18 IGL_INLINE void igl::covariance_scatter_matrix(
19 const Eigen::MatrixXd & V,
20 const Eigen::MatrixXi & F,
21 const ARAPEnergyType energy,
22 Eigen::SparseMatrix<double>& CSM)
23 {
24 using namespace Eigen;
25 // number of mesh vertices
26 int n = V.rows();
27 assert(n > F.maxCoeff());
28 // dimension of mesh
29 int dim = V.cols();
30 // Number of mesh elements
31 int m = F.rows();
32
33 // number of rotations
34 int nr;
35 switch(energy)
36 {
37 case ARAP_ENERGY_TYPE_SPOKES:
38 nr = n;
39 break;
40 case ARAP_ENERGY_TYPE_SPOKES_AND_RIMS:
41 nr = n;
42 break;
43 case ARAP_ENERGY_TYPE_ELEMENTS:
44 nr = m;
45 break;
46 default:
47 fprintf(
48 stderr,
49 "covariance_scatter_matrix.h: Error: Unsupported arap energy %d\n",
50 energy);
51 return;
52 }
53
54 SparseMatrix<double> KX,KY,KZ;
55 arap_linear_block(V,F,0,energy,KX);
56 arap_linear_block(V,F,1,energy,KY);
57 SparseMatrix<double> Z(n,nr);
58 if(dim == 2)
59 {
60 CSM = cat(1,cat(2,KX,Z),cat(2,Z,KY)).transpose();
61 }else if(dim == 3)
62 {
63 arap_linear_block(V,F,2,energy,KZ);
64 SparseMatrix<double>ZZ(n,nr*2);
65 CSM =
66 cat(1,cat(1,cat(2,KX,ZZ),cat(2,cat(2,Z,KY),Z)),cat(2,ZZ,KZ)).transpose();
67 }else
68 {
69 fprintf(
70 stderr,
71 "covariance_scatter_matrix.h: Error: Unsupported dimension %d\n",
72 dim);
73 return;
74 }
75
76 }
77