Point Set Shape Detection Reference

Sven Oesau, Yannick Verdie, Clément Jamin, Pierre Alliez, Florent Lafarge, Simon Giraudot

This component implements two primitive shape detection algorithms: efficient RANSAC and region growing. Planes are detected from point sets with unoriented normals. RANSAC also handles the following shapes: sphere, cylinder, cone and torus. Other types of shapes can be detected through implementing a class deriving from the base shape class.

Introduced in: CGAL 4.7
BibTeX: cgal:ovja-pssd-19a
License: GPL
Windows Demo: Polyhedron demo
Common Demo Dlls: dlls

Classified Reference Pages

Concept

• ShapeDetectionTraits

Main Classes

• CGAL::Shape_detection_3::Shape_detection_traits
• CGAL::Shape_detection_3::Efficient_RANSAC<Traits>
• CGAL::Shape_detection_3::Region_growing<Traits>

Shape Interface

• CGAL::Shape_detection_3::Shape_base<Traits>

Shape Classes

• CGAL::Shape_detection_3::Plane<Traits>
• CGAL::Shape_detection_3::Sphere<Traits>
• CGAL::Shape_detection_3::Cylinder<Traits>
• CGAL::Shape_detection_3::Cone<Traits>
• CGAL::Shape_detection_3::Torus<Traits>

Functions

• CGAL::regularize_planes()

Property Maps

• CGAL::Shape_detection_3::Plane_map<Traits>
• CGAL::Shape_detection_3::Point_to_shape_index_map<Traits>

Modules
	Concepts
	Shapes

Files
file	Shape_detection_3.h
	Convenience header file including the headers of this package.
file	regularize_planes.h

Classes
class	CGAL::Shape_detection_3::Efficient_RANSAC< Traits >
	A shape detection algorithm using a RANSAC method. More...
class	CGAL::Shape_detection_3::Region_growing< Traits >
	A shape detection algorithm using a region growing method. More...
struct	CGAL::Shape_detection_3::Shape_detection_traits< Gt, InputRange, InputPointMap, InputNormalMap >
	Default traits class to use the shape detection class Efficient_RANSAC. More...
class	CGAL::Shape_detection_3::Point_to_shape_index_map< Traits >
	Property map that associate a point index to its assigned shape found by a shape detection algorithm (such as CGAL::Shape_detection_3::Efficient_RANSAC or CGAL::Shape_detection_3::Region_growing). More...
class	CGAL::Shape_detection_3::Plane_map< Traits >
	Property map that associates a detected plane object (CGAL::Shape_detection_3::Plane) to a CGAL::Plane_3 object. More...

Functions
template<typename PointRange , typename PointMap , typename PlaneRange , typename PlaneMap , typename IndexMap , typename Kernel >
void	CGAL::regularize_planes (const PointRange &points, PointMap point_map, PlaneRange &planes, PlaneMap plane_map, IndexMap index_map, const Kernel &, bool regularize_parallelism, bool regularize_orthogonality, bool regularize_coplanarity, bool regularize_axis_symmetry, double tolerance_angle=25.0, double tolerance_coplanarity=0.01, typename Kernel::Vector_3 symmetry_direction=typename Kernel::Vector_3(0., 0., 1.))
	Given a set of detected planes with their respective inlier sets, this function enables to regularize the planes: More...

Function Documentation

regularize_planes()

template<typename PointRange , typename PointMap , typename PlaneRange , typename PlaneMap , typename IndexMap , typename Kernel >

void CGAL::regularize_planes	(	const PointRange &	points,
		PointMap	point_map,
		PlaneRange &	planes,
		PlaneMap	plane_map,
		IndexMap	index_map,
		const Kernel &	,
		bool	regularize_parallelism,
		bool	regularize_orthogonality,
		bool	regularize_coplanarity,
		bool	regularize_axis_symmetry,
		double	tolerance_angle = 25.0,
		double	tolerance_coplanarity = 0.01,
		typename Kernel::Vector_3	symmetry_direction = typename Kernel::Vector_3 (0., 0., 1.)
	)

#include <CGAL/regularize_planes.h>

Given a set of detected planes with their respective inlier sets, this function enables to regularize the planes:

• Planes near parallel can be made exactly parallel.
• Planes near orthogonal can be made exactly orthogonal.
• Planes parallel and near coplanar can be made exactly coplanar.
• Planes near symmetrical with a user-defined axis can be made exactly symmetrical.

Planes are directly modified. Points are left unaltered, as well as their relationships to planes (no transfer of point from a primitive plane to another).

The implementation follows [3].

Template Parameters

PointRange	range of points, model of ConstRange
PointPMap	is a model of ReadablePropertyMap with value type Kernel::Point_3. It can be omitted if the value type of the iterator of PointRange is convertible to Point_3<Kernel>.
PlaneRange	range of planes, model of Range
PlaneMap	is a model of WritablePropertyMap with value type Kernel::Plane_3. It can be omitted if the value type of the iterator of PlaneRange is convertible to Plane_3<Kernel>.
IndexMap	is a model of ReadablePropertyMap with value type int.
Kernel	Geometric traits class. It can be omitted and deduced automatically from the value type of PointMap.

Parameters

points	range of points.
point_map	property map: value_type of typename PointRange::const_iterator -> Point_3
planes	range of planes.
plane_map	property map: value_type of typename PlaneRange::iterator -> Plane_3
index_map	property map: index of point std::size_t -> index of plane int (-1 if the point is not assigned to a plane)
regularize_parallelism	Select whether parallelism is regularized or not.
regularize_orthogonality	Select whether orthogonality is regularized or not.
regularize_coplanarity	Select whether coplanarity is regularized or not.
regularize_axis_symmetry	Select whether axis symmetry is regularized or not.
tolerance_angle	Tolerance of deviation between normal vectors of planes (in degrees) used for parallelism, orthogonality and axis symmetry. Default value is 25 degrees.
tolerance_coplanarity	Maximal distance between two parallel planes such that they are considered coplanar. Default value is 0.01.
symmetry_direction	Chosen axis for symmetry regularization. Default value is the Z axis.

Examples:

Point_set_shape_detection_3/plane_regularization.cpp.