CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap > Class Template Reference

#include <CGAL/Shape_detection/Region_growing/Point_set/Least_squares_cylinder_fit_region.h>

Definition

template<typename GeomTraits, typename Item_, typename PointMap, typename NormalMap>
class CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >

Region type based on the quality of the least squares cylinder fit applied to 3D points.

This class fits an infinite cylinder to chunks of points in a 3D point set and controls the quality of this fit. If all quality conditions are satisfied, the chunk is accepted as a valid region, otherwise rejected.

Template Parameters

GeomTraits	a model of Kernel
Item_	a descriptor representing a given point. Must be a model of Hashable.
PointMap	a model of ReadablePropertyMap whose key type Item and value type is Kernel::Point_3
NormalMap	a model of ReadablePropertyMap whose key type is Item and value type is Kernel::Vector_3

Is model of

RegionType

Related Functions
(Note that these are not member functions.)
template<class PointSet3 >
using	Least_squares_cylinder_fit_region_for_point_set = Least_squares_cylinder_fit_region< typename Kernel_traits< typename PointSet3::Point_3 >::Kernel, typename PointSet3::Index, typename PointSet3::Point_map, typename PointSet3::Vector_map >
	shortcut to ease the definition of the class when using CGAL::Point_set_3.
template<class PointSet3 , typename NamedParameters = CGAL::parameters::Default_named_parameters>
Least_squares_cylinder_fit_region_for_point_set< PointSet3 >	make_least_squares_cylinder_fit_region (const PointSet3 &ps, const NamedParameters np=parameters::default_values())
	returns an instance of the sorting class to be used with CGAL::Point_set_3, with point and normal maps added to np.

Types
typedef GeomTraits::FT	FT
	Number type.
using	Item = Item_
	Item type.
using	Region = std::vector< Item >
using	Primitive = { typename GeomTraits::Line_3 axis
	Primitive.
using	Region_unordered_map = std::unordered_map< Item, std::size_t, internal::hash_item< Item > >
	Region map.
using	Region_index_map = boost::associative_property_map< Region_unordered_map >
GeomTraits::FT	radius

Initialization
template<typename NamedParameters = CGAL::parameters::Default_named_parameters>
	Least_squares_cylinder_fit_region (const NamedParameters &np=parameters::default_values())
	initializes all internal data structures.

Access
Region_index_map	region_index_map ()
	implements RegionType::region_index_map().
Primitive	primitive () const
	implements RegionType::primitive().
bool	is_part_of_region (const Item query, const Region &region) const
	implements RegionType::is_part_of_region().
bool	is_valid_region (const Region &region) const
	implements RegionType::is_valid_region().
bool	update (const Region &region)
	implements RegionType::update().

Constructor & Destructor Documentation

Least_squares_cylinder_fit_region()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

template<typename NamedParameters = CGAL::parameters::Default_named_parameters>

CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::Least_squares_cylinder_fit_region

(

const NamedParameters &

np = parameters::default_values()

)

initializes all internal data structures.

Template Parameters

NamedParameters

a sequence of Named Parameters

Parameters

np	a sequence of Named Parameters among the ones listed below

Optional Named Parameters

maximum_distance the maximum distance from a point to a cylinder Type: GeomTraits::FT Default: 1
maximum_angle the maximum angle in degrees between the normal of a point and the radius of a cylinder Type: GeomTraits::FT Default: 25 degrees
cosine_of_maximum_angle the cos value computed as cos(maximum_angle * PI / 180), this parameter can be used instead of the maximum_angle Type: GeomTraits::FT Default: cos(25 * PI / 180)
minimum_region_size the minimum number of 3D points a region must have Type: std::size_t Default: 3
minimum_radius the radius below which an estimated cylinder is considered as invalid and discarded Type: GeomTraits::FT Default: 0, no limit
maximum_radius the radius above which an estimated cylinder is considered as invalid and discarded. Type: GeomTraits::FT Default: +infinity, no limit
point_map an instance of PointMap that maps an item to GeomTraits::Point_3 Default: PointMap()
normal_map an instance of NormalMap that maps an item to GeomTraits::Vector_3 Default: NormalMap()
geom_traits an instance of GeomTraits Default: GeomTraits()

Precondition

maximum_distance >= 0

maximum_angle >= 0 && maximum_angle <= 90

cosine_of_maximum_angle >= 0 && cosine_of_maximum_angle <= 1

minimum_region_size > 0

minimum_radius >= 0

maximum_radius >= minimum_radius

Member Function Documentation

is_part_of_region()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

bool CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::is_part_of_region	(	const Item	query,
		const Region &	region
	)		const

implements RegionType::is_part_of_region().

This function controls if a point with the index query_index is within the maximum_distance from the corresponding cylinder and if the angle between its normal and the cylinder radius is within the maximum_angle. If both conditions are satisfied, it returns true, otherwise false.

Parameters

query	item of the query point
region	inlier items of the region

Returns

Boolean true or false

is_valid_region()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

bool CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::is_valid_region

(

const Region &

region

)

const

implements RegionType::is_valid_region().

This function controls if the estimated radius is between minimum_radius and maximum_radius and if the region contains at least min_region_size points.

Parameters

region

indices of points included in the region

Returns

Boolean true or false

primitive()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

Primitive CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::primitive

(

)

const

implements RegionType::primitive().

This function provides the last primitive that has been fitted with the region.

Returns

Primitive parameters that fits the region

Precondition

successful fitted primitive via successful call of update(region) with a sufficient large region

region_index_map()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

Region_index_map CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::region_index_map

(

)

implements RegionType::region_index_map().

This function creates an empty property map that maps iterators on the input range Item to std::size_t

update()

template<typename GeomTraits , typename Item_ , typename PointMap , typename NormalMap >

bool CGAL::Shape_detection::Point_set::Least_squares_cylinder_fit_region< GeomTraits, Item_, PointMap, NormalMap >::update

(

const Region &

region

)

implements RegionType::update().

This function fits the least squares cylinder to all points from the region.

Parameters

region

indices of points included in the region

Returns

Boolean true if the cylinder fitting succeeded and false otherwise

Precondition

region.size() > 0