GEO::CoplanarFacets Class Reference

Detects and retriangulates a set of coplanar facets for MeshSurfaceIntersection. More...

#include <geogram/mesh/mesh_surface_intersection_internal.h>

Public Types
typedef MeshSurfaceIntersection::ExactPoint	ExactPoint

Public Member Functions
	CoplanarFacets (MeshSurfaceIntersection &I, bool clear_attributes, double angle_tolerance=0.0)
	Constructs a CoplanarFacets object associated with a MeshSurfaceIntersection.
void	get (index_t f, index_t group_id)
	Gets the set of coplanar facets from a given facet and group id.
void	mark_vertices_to_keep ()
	Marks the vertices that need to be kept in the simplified facets.
void	save_borders (const std::string &filename)
	For debugging purposes, saves border edges to a file.
void	save_facet_group (const std::string &filename)
	For debugging purposes, saves all the facets of the group to a file.
void	triangulate ()
	Triangulates the kept vertices.
index_t	nb_facets ()
	Gets the number of coplanar facets.
void	mark_facets (vector< index_t > &facet_is_marked)
	Marks the facets.

Public Attributes
ExactCDT2d	CDT

Static Public Attributes
static constexpr index_t	NON_MANIFOLD = index_t(-2)

Protected Member Functions
void	find_coplanar_facets ()
	Finds all the pairs of coplanar facets.
bool	triangles_are_coplanar (const vec3 &p1, const vec3 &p2, const vec3 &p3, const vec3 &q1, const vec3 &q2, const vec3 &q3) const
	Tests whether two triangles are coplanar.
bool	edges_are_colinear (const ExactPoint &P1, const ExactPoint &P2, const ExactPoint &P3) const
	Tests whether two edges are co-linear.

Detailed Description

Detects and retriangulates a set of coplanar facets for MeshSurfaceIntersection.

Definition at line 493 of file mesh_surface_intersection_internal.h.

Member Typedef Documentation

ExactPoint

typedef MeshSurfaceIntersection::ExactPoint GEO::CoplanarFacets::ExactPoint

Definition at line 496 of file mesh_surface_intersection_internal.h.

Constructor & Destructor Documentation

CoplanarFacets()

GEO::CoplanarFacets::CoplanarFacets	(	MeshSurfaceIntersection &	I,
		bool	clear_attributes,
		double	angle_tolerance = 0.0
	)

Constructs a CoplanarFacets object associated with a MeshSurfaceIntersection.

No set of facets is identified. One needs to call get().

Parameters

[in]	I	a reference to the MeshSurfaceIntersection
[in]	clear_attributes	if set, resets facet_chart and keep_vertex
[in]	angle_tolerance	angle tolerance for detecting coplanar facets and colinear edges (in degrees)

Member Function Documentation

edges_are_colinear()

bool GEO::CoplanarFacets::edges_are_colinear ( const ExactPoint &  P1, const ExactPoint &  P2, const ExactPoint &  P3  ) const

protected

Tests whether two edges are co-linear.

Parameters

[in]

P1,P2,P3

the vertices of the two edges

Return values

true	if [P1,P2] and [P2,P3] are co-linear, and P2 is between P1 and p3
false	otherwise

uses angle_tolerance specified to the constructor (if set to zero, uses exact computation)

find_coplanar_facets()

void GEO::CoplanarFacets::find_coplanar_facets ( )

protected

Finds all the pairs of coplanar facets.

Initializes c_is_coplanar_[], a vector of booleans indexed by facet corners.

get()

void GEO::CoplanarFacets::get	(	index_t	f,
		index_t	group_id
	)

Gets the set of coplanar facets from a given facet and group id.

Uses the "group" facets attribute. If f's group is uninitialized (NO_INDEX), determines the facets of the group geometrically and initializes the attribute, else gets the facets based on the attribute.

Parameters

[in]	f	the facet
[in]	group_id	the facet group id

mark_facets()

void GEO::CoplanarFacets::mark_facets ( vector< index_t > &  facet_is_marked )

inline

Marks the facets.

Parameters

[out]

facet_is_marked

on exit, set to 1 for facets present in the list of coplanar facets. Needs to be of size mesh_.facets.nb().

Definition at line 613 of file mesh_surface_intersection_internal.h.

mark_vertices_to_keep()

void GEO::CoplanarFacets::mark_vertices_to_keep

(

)

Marks the vertices that need to be kept in the simplified facets.

A vertex is kept if it is incident to at least two non-colinear edges on the border. The status of the vertices is stored in the "keep" vertex attribute.

nb_facets()

index_t GEO::CoplanarFacets::nb_facets ( )

inline

Gets the number of coplanar facets.

Returns

the number of coplanar facets present in the mesh

Definition at line 603 of file mesh_surface_intersection_internal.h.

save_borders()

void GEO::CoplanarFacets::save_borders

(

const std::string &

filename

)

For debugging purposes, saves border edges to a file.

Parameters

[in]

filename

the file where to store the borders.

save_facet_group()

void GEO::CoplanarFacets::save_facet_group

(

const std::string &

filename

)

For debugging purposes, saves all the facets of the group to a file.

Parameters

[in]

filename

the file where to store the facets of the group.

triangles_are_coplanar()

bool GEO::CoplanarFacets::triangles_are_coplanar ( const vec3 &  p1, const vec3 &  p2, const vec3 &  p3, const vec3 &  q1, const vec3 &  q2, const vec3 &  q3  ) const

protected

Tests whether two triangles are coplanar.

This is used to determine the facets that can be merged

Parameters

[in]	p1,p2,p3	the vertices of the first triangle
[in]	q1,q2,q3	the vertices of the second triangle

Return values

true	if the two triangles are coplanar
false	otherwise

uses angle_tolerance specified to the constructor (if set to zero, uses exact computation)

triangulate()

void GEO::CoplanarFacets::triangulate

(

)

Triangulates the kept vertices.

One can get the triangle through the (public) CDT member (ExactCDT2d).

Member Data Documentation

CDT

ExactCDT2d GEO::CoplanarFacets::CDT

Definition at line 597 of file mesh_surface_intersection_internal.h.

NON_MANIFOLD

constexpr index_t GEO::CoplanarFacets::NON_MANIFOLD = index_t(-2)

staticconstexpr

Definition at line 495 of file mesh_surface_intersection_internal.h.

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The documentation for this class was generated from the following file:

• geogram/mesh/mesh_surface_intersection_internal.h