Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/lbs_matrix.cpp

@@ -0,0 +1,184 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2014 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "lbs_matrix.h"
+
+IGL_INLINE void igl::lbs_matrix(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXd & W,
+  Eigen::MatrixXd & M)
+{
+  using namespace Eigen;
+  // Number of dimensions
+  const int dim = V.cols();
+  // Number of model points
+  const int n = V.rows();
+  // Number of skinning transformations/weights
+  const int m = W.cols();
+
+  // Assumes that first n rows of weights correspond to V
+  assert(W.rows() >= n);
+
+  M.resize(n,(dim+1)*m);
+  for(int j = 0;j<m;j++)
+  {
+    VectorXd Wj = W.block(0,j,V.rows(),1);
+    for(int i = 0;i<(dim+1);i++)
+    {
+      if(i<dim)
+      {
+        M.col(i + j*(dim+1)) = 
+          Wj.cwiseProduct(V.col(i));
+      }else
+      {
+        M.col(i + j*(dim+1)).array() = W.block(0,j,V.rows(),1).array();
+      }
+    }
+  }
+}
+
+IGL_INLINE void igl::lbs_matrix_column(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXd & W,
+  Eigen::SparseMatrix<double>& M)
+{
+  // number of mesh vertices
+  int n = V.rows();
+  assert(n == W.rows());
+  // dimension of mesh
+  int dim = V.cols();
+  // number of handles
+  int m = W.cols();
+
+  M.resize(n*dim,m*dim*(dim+1));
+
+  // loop over coordinates of mesh vertices
+  for(int x = 0; x < dim; x++)
+  {
+    // loop over mesh vertices
+    for(int j = 0; j < n; j++)
+    {
+      // loop over handles
+      for(int i = 0; i < m; i++)
+      {
+        // loop over cols of affine transformations
+        for(int c = 0; c < (dim+1); c++)
+        {
+          double value = W(j,i);
+          if(c<dim)
+          {
+            value *= V(j,c);
+          }
+          M.insert(x*n + j,x*m + c*m*dim + i) = value;
+        }
+      }
+    }
+  }
+
+  M.makeCompressed();
+}
+
+IGL_INLINE void igl::lbs_matrix_column(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXd & W,
+  Eigen::MatrixXd & M)
+{
+  // number of mesh vertices
+  int n = V.rows();
+  assert(n == W.rows());
+  // dimension of mesh
+  int dim = V.cols();
+  // number of handles
+  int m = W.cols();
+  M.resize(n*dim,m*dim*(dim+1));
+
+  // loop over coordinates of mesh vertices
+  for(int x = 0; x < dim; x++)
+  {
+    // loop over mesh vertices
+    for(int j = 0; j < n; j++)
+    {
+      // loop over handles
+      for(int i = 0; i < m; i++)
+      {
+        // loop over cols of affine transformations
+        for(int c = 0; c < (dim+1); c++)
+        {
+          double value = W(j,i);
+          if(c<dim)
+          {
+            value *= V(j,c);
+          }
+          M(x*n + j,x*m + c*m*dim + i) = value;
+        }
+      }
+    }
+  }
+}
+
+IGL_INLINE void igl::lbs_matrix_column(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXd & W,
+  const Eigen::MatrixXi & WI,
+  Eigen::SparseMatrix<double>& M)
+{
+  // number of mesh vertices
+  int n = V.rows();
+  assert(n == W.rows());
+  assert(n == WI.rows());
+  // dimension of mesh
+  int dim = V.cols();
+  // number of handles
+  int m = WI.maxCoeff()+1;
+  // max number of influencing handles
+  int k = W.cols();
+  assert(k == WI.cols());
+
+  M.resize(n*dim,m*dim*(dim+1));
+
+  // loop over coordinates of mesh vertices
+  for(int x = 0; x < dim; x++)
+  {
+    // loop over mesh vertices
+    for(int j = 0; j < n; j++)
+    {
+      // loop over handles
+      for(int i = 0; i < k; i++)
+      {
+        // loop over cols of affine transformations
+        for(int c = 0; c < (dim+1); c++)
+        {
+          double value = W(j,i);
+          if(c<dim)
+          {
+            value *= V(j,c);
+          }
+          if(value != 0)
+          {
+            M.insert(x*n + j,x*m + c*m*dim + WI(j,i)) = value;
+          }
+        }
+      }
+    }
+  }
+
+  M.makeCompressed();
+}
+
+
+IGL_INLINE void igl::lbs_matrix_column(
+  const Eigen::MatrixXd & V, 
+  const Eigen::MatrixXd & W,
+  const Eigen::MatrixXi & WI,
+  Eigen::MatrixXd & M)
+{
+  // Cheapskate wrapper
+  using namespace Eigen;
+  SparseMatrix<double> sM;
+  lbs_matrix_column(V,W,WI,sM);
+  M = MatrixXd(sM);
+}