dust3d/third_party/libigl/include/igl/fast_winding_number.h

119 lines
5.5 KiB
C++

#ifndef IGL_FAST_WINDING_NUMBER
#define IGL_FAST_WINDING_NUMBER
#include "igl_inline.h"
#include <Eigen/Core>
#include <vector>
namespace igl
{
// Generate the precomputation for the fast winding number for point data
// [Barill et. al 2018].
//
// Given a set of 3D points P, with normals N, areas A, along with octree
// data, and an expansion order, we define a taylor series expansion at each
// octree cell.
//
// The octree data is designed to come from igl::octree, and the areas
// (if not obtained at scan time), may be calculated using
// igl::copyleft::cgal::point_areas.
//
// Inputs:
// P #P by 3 list of point locations
// N #P by 3 list of point normals
// A #P by 1 list of point areas
// point_indices a vector of vectors, where the ith entry is a vector of
// the indices into P that are the ith octree cell's points
// CH #OctreeCells by 8, where the ith row is the indices of
// the ith octree cell's children
// expansion_order the order of the taylor expansion. We support 0,1,2.
// Outputs:
// CM #OctreeCells by 3 list of each cell's center of mass
// R #OctreeCells by 1 list of each cell's maximum distance of any point
// to the center of mass
// EC #OctreeCells by #TaylorCoefficients list of expansion coefficients.
// (Note that #TaylorCoefficients = ∑_{i=1}^{expansion_order} 3^i)
//
template <typename DerivedP, typename DerivedA, typename DerivedN,
typename Index, typename DerivedCH, typename DerivedCM, typename DerivedR,
typename DerivedEC>
IGL_INLINE void fast_winding_number(const Eigen::MatrixBase<DerivedP>& P,
const Eigen::MatrixBase<DerivedN>& N,
const Eigen::MatrixBase<DerivedA>& A,
const std::vector<std::vector<Index> > & point_indices,
const Eigen::MatrixBase<DerivedCH>& CH,
const int expansion_order,
Eigen::PlainObjectBase<DerivedCM>& CM,
Eigen::PlainObjectBase<DerivedR>& R,
Eigen::PlainObjectBase<DerivedEC>& EC);
// Evaluate the fast winding number for point data, having already done the
// the precomputation
//
// Inputs:
// P #P by 3 list of point locations
// N #P by 3 list of point normals
// A #P by 1 list of point areas
// point_indices a vector of vectors, where the ith entry is a vector of
// the indices into P that are the ith octree cell's points
// CH #OctreeCells by 8, where the ith row is the indices of
// the ith octree cell's children
// CM #OctreeCells by 3 list of each cell's center of mass
// R #OctreeCells by 1 list of each cell's maximum distance of any point
// to the center of mass
// EC #OctreeCells by #TaylorCoefficients list of expansion coefficients.
// (Note that #TaylorCoefficients = ∑_{i=1}^{expansion_order} 3^i)
// Q #Q by 3 list of query points for the winding number
// beta This is a Barnes-Hut style accuracy term that separates near feild
// from far field. The higher the beta, the more accurate and slower
// the evaluation. We reccommend using a beta value of 2. Note that
// for a beta value ≤ 0, we use the direct evaluation, rather than
// the fast approximation
// Outputs:
// WN #Q by 1 list of windinng number values at each query point
//
template <typename DerivedP, typename DerivedA, typename DerivedN,
typename Index, typename DerivedCH, typename DerivedCM, typename DerivedR,
typename DerivedEC, typename DerivedQ, typename BetaType,
typename DerivedWN>
IGL_INLINE void fast_winding_number(const Eigen::MatrixBase<DerivedP>& P,
const Eigen::MatrixBase<DerivedN>& N,
const Eigen::MatrixBase<DerivedA>& A,
const std::vector<std::vector<Index> > & point_indices,
const Eigen::MatrixBase<DerivedCH>& CH,
const Eigen::MatrixBase<DerivedCM>& CM,
const Eigen::MatrixBase<DerivedR>& R,
const Eigen::MatrixBase<DerivedEC>& EC,
const Eigen::MatrixBase<DerivedQ>& Q,
const BetaType beta,
Eigen::PlainObjectBase<DerivedWN>& WN);
// Evaluate the fast winding number for point data, with default expansion
// order and beta (both are set to 2).
//
// This function performes the precomputation and evaluation all in one.
// If you need to acess the precomuptation for repeated evaluations, use the
// two functions designed for exposed precomputation (described above).
//
// Inputs:
// P #P by 3 list of point locations
// N #P by 3 list of point normals
// A #P by 1 list of point areas
// Q #Q by 3 list of query points for the winding number
// Outputs:
// WN #Q by 1 list of windinng number values at each query point
//
template <typename DerivedP, typename DerivedA, typename DerivedN,
typename DerivedQ, typename DerivedWN>
IGL_INLINE void fast_winding_number(const Eigen::MatrixBase<DerivedP>& P,
const Eigen::MatrixBase<DerivedN>& N,
const Eigen::MatrixBase<DerivedA>& A,
const Eigen::MatrixBase<DerivedQ>& Q,
Eigen::PlainObjectBase<DerivedWN>& WN
);
}
#ifndef IGL_STATIC_LIBRARY
# include "fast_winding_number.cpp"
#endif
#endif