Basic functions used by global surface parameterization algorithms (PGP, QuadCover). More...

#include <geogram/basic/common.h>
#include <geogram/basic/attributes.h>
#include <geogram/basic/geometry.h>

Namespaces
namespace	GEO
	Global Vorpaline namespace.

Enumerations
enum	{ CNSTR_NONE = 0 , CNSTR_U = 1 , CNSTR_V = 2 }

Functions
void	GEO::GlobalParam2d::frame_field (Mesh *mesh, Attribute< vec3 > &B, double hard_angle_threshold=45.0)
	Computes a guidance frame field for global parameterization.

void	GEO::GlobalParam2d::Internal::compute_R_ff (Mesh *mesh, Attribute< vec3 > &B, Attribute< index_t > &R_ff)
	Computes for each pair of adjacent facets the number of times the facet vector B should be rotated along the facet normal to minimize its angle with the vector B of the adjacent facet.

void	GEO::GlobalParam2d::Internal::compute_R_fv (Mesh *mesh, Attribute< index_t > &R_ff, Attribute< index_t > &R_fv)
	Computes for each facet corner the number of times the facet vector B should be rotated along the facet normal to minimize its angle with the vector B of a reference facet attached to each vertex.

void	GEO::GlobalParam2d::Internal::mark_singular_vertices (Mesh *mesh, Attribute< index_t > &R_ff, Attribute< bool > &v_is_singular)
	Marks the singular vertices of the direction field.

void	GEO::GlobalParam2d::Internal::brush (Mesh *mesh, Attribute< vec3 > &B)
	Brushes the direction field.

void	GEO::GlobalParam2d::Internal::do_the_ball (Mesh *mesh, Attribute< index_t > &R_ff, Attribute< index_t > &c_on_border)
	Computes the border of the ball.

void	GEO::GlobalParam2d::Internal::do_the_ball_no_brush_no_zip (Mesh *mesh, Attribute< index_t > &c_on_border)
	Computes the border of the ball.

void	GEO::GlobalParam2d::Internal::get_B_on_edge (Mesh *mesh, Attribute< vec3 > &B, Attribute< index_t > &R_ff, index_t f, index_t c, vec3 &Bc, vec3 &BTc)
	Gets the field B evaluated at a given mesh edge.

void	GEO::GlobalParam2d::Internal::get_constraints (Mesh *mesh, Attribute< vec3 > &B, Attribute< index_t > &R_ff, Attribute< index_t > &constraint)
	Determines the constraints for all edges of the mesh.

index_t	GEO::GlobalParam2d::Internal::get_edge_constraints (Mesh *mesh, index_t c, Attribute< vec3 > &B)
	Tests whether U and V are constrained for a given edge.

index_t	GEO::GlobalParam2d::Internal::inverse_R (index_t R)
	Gets the inverse of a rotation.

void	GEO::GlobalParam2d::Internal::snap_tex_coord (double &coord)
	Snaps a texture coordinate.

void	GEO::GlobalParam2d::Internal::transfer_B_to_vertices (Mesh *mesh, Attribute< vec3 > &B, Attribute< vec3 > &Bv, Attribute< index_t > &R_fv)
	Transfers a facet vector field to a vertex vector field.

Detailed Description

Basic functions used by global surface parameterization algorithms (PGP, QuadCover).

Definition in file mesh_global_param.h.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Definition at line 186 of file mesh_global_param.h.

Function Documentation

◆ brush()

void GEO::GlobalParam2d::Internal::brush	(	Mesh *	mesh,
		Attribute< vec3 > &	B
	)

Brushes the direction field.

Makes the field rotation between adjacent facets equal to zero over a covering tree of the surface.

Parameters

[in]	mesh	a pointer to a surface mesh
[in,out]	B	a facet attribute with the guidance vector field one 3d vector per facet).

◆ compute_R_ff()

void GEO::GlobalParam2d::Internal::compute_R_ff	(	Mesh *	mesh,
		Attribute< vec3 > &	B,
		Attribute< index_t > &	R_ff
	)

Computes for each pair of adjacent facets the number of times the facet vector B should be rotated along the facet normal to minimize its angle with the vector B of the adjacent facet.

Parameters

[in]	mesh	a pointer to a surface mesh
[in]	B	a vec3 attribute attached to the facets
[out]	R_ff	an index_t attribute attached to facet corners, in 0,1,2,3

◆ compute_R_fv()

void GEO::GlobalParam2d::Internal::compute_R_fv	(	Mesh *	mesh,
		Attribute< index_t > &	R_ff,
		Attribute< index_t > &	R_fv
	)

Computes for each facet corner the number of times the facet vector B should be rotated along the facet normal to minimize its angle with the vector B of a reference facet attached to each vertex.

Parameters

[in]	mesh	a pointer to a surface mesh
[in]	R_ff	an index_t attribute attached to facet corners, computed by compute_R_ff().
[out]	R_fv	an index_t attribute attached to facet corners, in 0,1,2,3

◆ do_the_ball()

void GEO::GlobalParam2d::Internal::do_the_ball	(	Mesh *	mesh,
		Attribute< index_t > &	R_ff,
		Attribute< index_t > &	c_on_border
	)

Computes the border of the ball.

Parameters

[in]	mesh	a pointer to a surface mesh
[in]	R_ff	the Rij corner attribute indicating how many times the vector associated with facet j should be rotated by 90 degrees around its facet normal to match the vector associated with facet i. It is computed by compute_R_ff().
[out]	c_on_border	a facet corner attribute that contains 1 if the halfede edge is on the border of the ball, 0 otherwise

◆ do_the_ball_no_brush_no_zip()

void GEO::GlobalParam2d::Internal::do_the_ball_no_brush_no_zip	(	Mesh *	mesh,
		Attribute< index_t > &	c_on_border
	)

Computes the border of the ball.

This version does not suppose that the B's are brushed and only computes the facet covering tree (no zipping).

Parameters

[in]	mesh	a pointer to a surface mesh
[out]	c_on_border	a facet corner attribute that contains 1 if the halfede edge is on the border of the ball, 0 otherwise

◆ frame_field()

void GEO::GlobalParam2d::frame_field	(	Mesh *	mesh,
		Attribute< vec3 > &	B,
		double	hard_angle_threshold = `45.0`
	)

Computes a guidance frame field for global parameterization.

Creates the vector field in the "B" facet attribute, of type vec3.

Parameters

[in]	mesh	a pointer to a surface mesh.
[out]	B	a facet attribute with the computed frame field.
[in]	hard_angle_threshold	edges with a facet angle larger than this threshold are fixed as constraints for the frame field.

◆ get_B_on_edge()

void GEO::GlobalParam2d::Internal::get_B_on_edge	(	Mesh *	mesh,
		Attribute< vec3 > &	B,
		Attribute< index_t > &	R_ff,
		index_t	f,
		index_t	c,
		vec3 &	Bc,
		vec3 &	BTc
	)

Gets the field B evaluated at a given mesh edge.

If the edge is incident to two facets, then the field is averaged.

Parameters

[in]	mesh	a pointer to a surface mesh.
[in,out]	B	a facet attribute with the guidance vector field, one 3d vector per facet).
[in]	R_ff	the Rij corner attribute indicating how many times the vector associated with facet j should be rotated by 90 degrees around its facet normal to match the vector associated with facet i. It is computed by compute_R_ff().
[in]	f	a mesh facet.
[in]	c	a corner of facet p f.
[out]	Bc	the field along the edge originated from corner `c` of facet `f`.
[out]	BTc	the orthogonal field along the edge originated from corner `c` of facet `f`.

◆ get_constraints()

void GEO::GlobalParam2d::Internal::get_constraints	(	Mesh *	mesh,
		Attribute< vec3 > &	B,
		Attribute< index_t > &	R_ff,
		Attribute< index_t > &	constraint
	)

Determines the constraints for all edges of the mesh.

Parameters

[in]	mesh	a pointer to a surface mesh.
[in,out]	B	a facet attribute with the guidance vector field, one 3d vector per facet).
[in]	R_ff	the Rij corner attribute indicating how many times the vector associated with facet j should be rotated by 90 degrees around its facet normal to match the vector associated with facet i. It is computed by compute_R_ff().
[out]	constraint	for each corner, a binary-or combination of CNSTR_U and CNSTR_V.

◆ get_edge_constraints()

index_t GEO::GlobalParam2d::Internal::get_edge_constraints	(	Mesh *	mesh,
		index_t	c,
		Attribute< vec3 > &	B
	)

Tests whether U and V are constrained for a given edge.

An edge is constrained if it is a border edge or if it is sharp. The coordinate that is constrained is determined from the dot product betwee the edge vector and B.

Parameters

[in]	mesh	a pointer to a surface mesh.
[in]	c	a corner incident to the edge.
[in,out]	B	a facet attribute with the guidance vector field one 3d vector per facet).

Returns: One of CNSTR_U, CNSTR_V, CNSTR_U | CNSTR_V.

◆ inverse_R()

index_t GEO::GlobalParam2d::Internal::inverse_R ( index_t R )

Gets the inverse of a rotation.

Parameters

[in] R the rotation in angus (in 0,1,2,3)

Returns: the inverse of R in angus (in 0,1,2,3)

◆ mark_singular_vertices()

void GEO::GlobalParam2d::Internal::mark_singular_vertices	(	Mesh *	mesh,
		Attribute< index_t > &	R_ff,
		Attribute< bool > &	v_is_singular
	)

Marks the singular vertices of the direction field.

Parameters

[in]	mesh	a pointer to a surface mesh
[in]	R_ff	the Rij corner attribute indicating how many times the vector associated with facet j should be rotated by 90 degrees around its facet normal to match the vector associated with facet i. It is computed by compute_R_ff().
[out]	v_is_singular	a vertex attribute that indicates for each vertex whether it is singular.

◆ snap_tex_coord()

void GEO::GlobalParam2d::Internal::snap_tex_coord ( double & coord )

Snaps a texture coordinate.

This is required by the mesh extraction algorithm.

Parameters

[in,out] coord the coordinate to be snapped.

◆ transfer_B_to_vertices()

void GEO::GlobalParam2d::Internal::transfer_B_to_vertices	(	Mesh *	mesh,
		Attribute< vec3 > &	B,
		Attribute< vec3 > &	Bv,
		Attribute< index_t > &	R_fv
	)

Transfers a facet vector field to a vertex vector field.

Parameters

[in]	mesh	a pointer to a surface mesh.
[in]	B	a facet attribute with the guidance vector field one 3d vector per facet).
[out]	Bv	a vertex attribute with the guidance vector field one 3d vector per vertex).
[in]	R_fv	the Rij corner attribute indicating how many times the vector associated with facet j should be rotated by 90 degrees around its facet normal to match the vector attached to the vertex. It is computed by compute_R_fv().

Namespaces

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

◆ anonymous enum

Function Documentation

◆ brush()

◆ compute_R_ff()

◆ compute_R_fv()

◆ do_the_ball()

◆ do_the_ball_no_brush_no_zip()

◆ frame_field()

◆ get_B_on_edge()

◆ get_constraints()

◆ get_edge_constraints()

◆ inverse_R()

◆ mark_singular_vertices()

◆ snap_tex_coord()

◆ transfer_B_to_vertices()