Interface for iterative closest points. More...

#include <icp.h>

Inherited by icp::Trimmed, and icp::Vanilla.

Classes
class	Config
	Configuration for ICP instances. More...

struct	ConvergenceReport
	The result of running `ICP::converge`. More...

struct	Match
	A point-to-point matching between `point` and `pair` at a distance of `sqrt(sq_dist)`. More...

Public Member Functions
virtual	~ICP ()=default

void	begin (const std::vector< Vector > &a, const std::vector< Vector > &b, RBTransform t)
	Begins the ICP process for point clouds `a` and `b` with an initial guess for the transform `t`.

virtual void	iterate ()=0
	Perform one iteration of ICP for the point clouds `a` and `b` provided with ICP::begin.

double	calculate_cost () const
	Computes the cost of the current transformation.

ConvergenceReport	converge (size_t burn_in, double convergence_threshold)
	Perform ICP for the point clouds `a` and `b` provided with ICP::begin until the cost is below `convergence_threshold` or until no progress is being made.

const RBTransform &	current_transform () const
	The current transform.

Static Public Member Functions
static bool	register_method (std::string name, std::function< std::unique_ptr< ICP >(const Config &)> constructor)
	Registers a new ICP method that can be created with `constructor`, returning `false` if `name` has already been registered.

static const std::vector< std::string > &	registered_methods ()
	Returns a current list of the names of currently registered ICP methods.

static std::unique_ptr< ICP >	from_method (std::string name, const Config &params=Config())
	Factory constructor for the ICP method `name` with configuration `config`.

static bool	is_registered_method (std::string name)
	Whether `name` is a registered ICP method.

Protected Member Functions
	ICP ()

virtual void	setup ()

Protected Attributes
RBTransform	transform
	The current point cloud transformation that is being optimized.

std::vector< Vector >	a
	The source point cloud relative to its centroid.

std::vector< Vector >	b
	The destination point cloud relative to its centroid.

double	previous_cost
	Keeps track of the previous cost to ensure that progress is being made.

double	current_cost
	The RMS (root mean square) cost of the current transformation.

std::vector< Match >	matches
	The pairing of each point in `a` to its closest in `b`.

Detailed Description

Interface for iterative closest points.

You should interact with ICP instances through this API only. Read Writing an ICP Instance for additional information.

Example: // Construct a new vanilla ICP instance.

std::unique_ptr<icp::ICP> icp = icp::ICP::from_method("vanilla");

icp::ICP::from_method
static std::unique_ptr< ICP > from_method(std::string name, const Config &params=Config())
Factory constructor for the ICP method name with configuration config.
Definition icp.cpp:98

icp
Definition geo.cpp:9

Usage: Let a and b be two point clouds of type std::vector<Vector>. Then, given an ICP instance icp of type std::unique_ptr<icp::ICP>, perform the following steps.

Call icp->begin(a, b, initial_guess).
Call either icp->converge(convergence_threshold) or repeatedly icp->iterate().

If these steps are not followed as described here, the behavior is undefined.

At any point in the process, you may query icp->calculate_cost() and icp->transform(). Do note, however, that icp->calculate_cost() is not a constant-time operation.

Definition at line 45 of file icp.h.

Constructor & Destructor Documentation

◆ ICP()

icp::ICP::ICP ( )

protected

Definition at line 12 of file icp.cpp.

◆ ~ICP()

virtual icp::ICP::~ICP ( )

virtualdefault

Member Function Documentation

◆ begin()

void icp::ICP::begin	(	const std::vector< Vector > &	a,
		const std::vector< Vector > &	b,
		RBTransform	t )

Begins the ICP process for point clouds a and b with an initial guess for the transform t.

Definition at line 16 of file icp.cpp.

◆ calculate_cost()

double icp::ICP::calculate_cost ( ) const

Computes the cost of the current transformation.

Efficiency:: O(a.size()) where a is the source point cloud.

Definition at line 38 of file icp.cpp.

◆ converge()

ICP::ConvergenceReport icp::ICP::converge	(	size_t	burn_in,
		double	convergence_threshold )

Perform ICP for the point clouds a and b provided with ICP::begin until the cost is below convergence_threshold or until no progress is being made.

At least burn_in iterations will be performed. Start with zero burn-in, and slowly increase if convergence requirements are not met.

Returns: Information about the convergence.

Precondition: ICP::begin must have been invoked.

Definition at line 46 of file icp.cpp.

◆ current_transform()

const RBTransform & icp::ICP::current_transform ( ) const

The current transform.

Definition at line 75 of file icp.cpp.

◆ from_method()

std::unique_ptr< ICP > icp::ICP::from_method	(	std::string	name,
		const Config &	params = Config() )

static

Factory constructor for the ICP method name with configuration config.

Precondition: name is a valid registered method. See ICP::is_registered_method.

Definition at line 98 of file icp.cpp.

◆ is_registered_method()

bool icp::ICP::is_registered_method ( std::string name )

static

Whether name is a registered ICP method.

Definition at line 106 of file icp.cpp.

◆ iterate()

virtual void icp::ICP::iterate ( )

pure virtual

Perform one iteration of ICP for the point clouds a and b provided with ICP::begin.

Precondition: ICP::begin must have been invoked.

◆ register_method()

bool icp::ICP::register_method	(	std::string	name,
		std::function< std::unique_ptr< ICP >(const Config &)>	constructor )

static

Registers a new ICP method that can be created with constructor, returning false if name has already been registered.

Definition at line 85 of file icp.cpp.

◆ registered_methods()

const std::vector< std::string > & icp::ICP::registered_methods ( )

static

Returns a current list of the names of currently registered ICP methods.

Definition at line 93 of file icp.cpp.

◆ setup()

void icp::ICP::setup ( )

protectedvirtual

Definition at line 14 of file icp.cpp.

Member Data Documentation

◆ a

std::vector<Vector> icp::ICP::a

protected

The source point cloud relative to its centroid.

Definition at line 61 of file icp.h.

◆ b

std::vector<Vector> icp::ICP::b

protected

The destination point cloud relative to its centroid.

Definition at line 64 of file icp.h.

◆ current_cost

double icp::ICP::current_cost

protected

The RMS (root mean square) cost of the current transformation.

Definition at line 71 of file icp.h.

◆ matches

std::vector<Match> icp::ICP::matches

protected

The pairing of each point in a to its closest in b.

Definition at line 74 of file icp.h.

◆ previous_cost

double icp::ICP::previous_cost

protected

Keeps track of the previous cost to ensure that progress is being made.

See also: ICP::current_cost.

Definition at line 68 of file icp.h.

◆ transform

RBTransform icp::ICP::transform

protected

The current point cloud transformation that is being optimized.

Definition at line 58 of file icp.h.

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

src/icp/icp.h
src/icp/icp.cpp

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ICP()

◆ ~ICP()

Member Function Documentation

◆ begin()

◆ calculate_cost()

◆ converge()

◆ current_transform()

◆ from_method()

◆ is_registered_method()

◆ iterate()

◆ register_method()

◆ registered_methods()

◆ setup()

Member Data Documentation

◆ a

◆ b

◆ current_cost

◆ matches

◆ previous_cost

◆ transform