Meshes¶

This module provides a MeshData class for defining a Surface_Mesh and performing related operations.

class MeshData¶

Class to hold a polyhedron mesh.

This is a wrapper of the Surface_mesh from CGAL and is the foundation used for the asteroid polyhedron potential model.

Author: Shankar Kulumani
Version: 28 October 2018

Public Functions

void update_mesh(const Eigen::Ref<const Eigen::MatrixXd> &V, const Eigen::Ref<const Eigen::MatrixXi> &F)¶

Completely update the mesh with new vertices and faces. This will also completely regenerate the mesh properties

Return

void

Author

Shankar Kulumani

Version

9 June 2018

Parameters

V: Eigen matrix with the vertices
F: Eigen matrix with teh faces

build_edge_factor(const Eigen::Ref<const Eigen::Vector3d> &pos)¶

Build the per edge factor L for the polyhedron potential model

Return

bool Success if true

Author

Shankar Kulumani

Version

28 October 2018

Parameters

pos: Position of test point

build_face_factor(const Eigen::Ref<const Eigen::Vector3d> &pos)¶

Build the per face factor w for the polyhedron potential model

Return

bool success if true

Author

Shankar Kulumani

Version

28 October 2018

Parameters

pos: Position of test point

get_verts(void) const¶

Return the vertices of the mesh as an Eigen array

Return: vertices Eigen arrays for the mesh nx3
Author: Shankar Kulumani
Version: 28 October 2018

Eigen::Matrix<int, Eigen::Dynamic, 3> get_faces(void) const¶

Return the faces of the mesh as an eigen array

Return: faces Eigen array for the faces of the mesh nx3
Author: Shankar Kulumani
Version: 28 October 2018

std::size_t number_of_vertices(void) const¶

Return the number of vertices of the mesh

Return: num_vert Return the number of vertices
Author: Shankar Kulumani
Version: 28 October 2018

std::size_t number_of_edges(void) const¶

Return number of edges of the mesh

Return: num_edge Number of edges
Author: Shankar Kulumani
Version: 28 October 2018

std::size_t number_of_faces(void) const¶

Return number of faces of the mesh

Return: num_face Number of faces
Author: Shankar Kulumani
Version: 28 October 2018

std::size_t number_of_halfedges(void) const¶

Return number of halfedges of the mesh

Return: num_half Number of halfedges
Author: Shankar Kulumani
Version: 28 October 2018

Mesh::Vertex_range vertices(void) const¶

Return vertex range for iteration

Return: Vertex_range Range of vertices of the mesh
Author: Shankar Kulumani
Version: 28 October 2018

Mesh::Face_range faces(void) const¶

Return face range for iteration

Return: Face_range Range of faces of the mesh
Author: Shankar Kulumani
Version: 28 October 2018

Mesh::Edge_range edges(void) const¶

Return edge range for iteration

Return: Edge_range Range of edges of the mesh
Author: Shankar Kulumani
Version: 28 October 2018

Mesh::Halfedge_range halfedges(void) const¶

Return halfedge range for iteration

Return: Halfedge_range Range of halfedges of the mesh
Author: Shankar Kulumani
Version: 28 October 2018

bool refine_faces(const std::vector<Face_index> &face_vec, std::vector<Face_index> &new_faces, std::vector<Vertex_index> &new_vertices, const int &density = 4.0)¶

Given a set of faces, this will refine them by adding new faces/ vertices within them. The new faces and vertices are returned. The surface mesh member variable is updated.

This tends to make a very craggly shape. Better to use remesh instead

Return

new_faces Vector of new faces

Return

new_vertices Vector of new vertices

Author

Shankar Kulumani

Version

10 June 2018

Parameters

face_vec: Vector of faces to refine
density: integer defining the density control factor

remesh_faces(const std::vector<Face_index> &face_vec, const double &target_edge_length, const int &number_of_iterations = 3)¶

Perform isotropic remeshing of the desired faces of the mesh.

Return

bool True if success

Author

Shankar Kulumani

Version

28 October 2018

Parameters

face_vec: Vector of faces to remesh
target_edge_length: Target length of the new edges
number_of_iterations: Iterations for isotropic_remeshing

std::vector<Face_index> faces_in_fov(const Eigen::Ref<const Eigen::Vector3d> &pos, const double &max_fov = 0.52)¶

Find the faces that are within a FOV of the current position

Return

face_vec Vector of face indices

Author

Shankar Kulumani

Version

11 June 2018

Parameters

pos: Position of spacecraft in the asteroid fixed frame

std::vector<Face_index> vertices_in_fov(const Eigen::Ref<const Eigen::Vector3d> &pos, const double &max_fov = 0.52)¶

Find the vertices that are within a FOV of the current position

Return

vertex_vec Vector of vertex indices

Author

Shankar Kulumani

Version

28 October 2018

Parameters

pos: Position of spacecraft in the asteroid fixed frame

Eigen::Matrix<double, Eigen::Dynamic, 3> refine_faces_in_view(const Eigen::Ref<const Eigen::Vector3d> &pos, const double &max_fov = 0.52)¶

Use the refinement function for the faces within a certain angle of the position

Return

Face_centers get the center of the new faces in view

Author

Shankar Kulumani

Version

28 October 2018

Parameters

pos: Eigen vector for position
max_fov: Maximum cosine(angle) for faces to refine

bool remesh_faces_in_view(const Eigen::Ref<const Eigen::Vector3d> &pos, const double &max_fov = 0.52, const double &edge_length = 0.01)¶

Use isotropic remeshing to remesh the faces that are in view of the point

Return

bool Success if true

Author

Shankar Kulumani

Version

28 October 2018

Parameters

pos: Position vector
max_fov: Field of view to use to compute the faces in view
edge_length: Target edge length for the new faces

template <typename Index> Eigen::RowVector3d get_vertex(const Index &index) const¶

Get the desired vertex given an index

Return

vertex Eigen array of the specific vertex

Author

Shankar Kulumani

Version

28 October 2018

Parameters

Index: Index of vertex to get

bool set_vertex(const Vertex_index &vd, const Eigen::Ref<const Eigen::Vector3d> &vec)¶

Update the position of a single vertex and recompute the affected mesh properties

Return

bool True if good

Author

Shankar Kulumani

Version

9 June 2018

Parameters

vd: Vertex index to modify
vec: Eigen vector of the new vertex position

template <typename Index> Eigen::RowVector3i get_face_vertices(const Index &index) const¶

Get the vertex indecies of all vertices in the face

Return

row a row vector of indices

Author

Shankar Kulumani

Version

6 June 2018

Parameters

index: A face index (basically an integer)

Eigen::VectorXd get_all_face_area(void) const¶

Get the area of each face of the mesh

Return

Vector of all face areas

Author

Shankar Kulumani

Version

12 June 2018

Parameters

void: none

Public Members

Mesh surface_mesh¶: Surface_mesh object