Mesh sampling algorithms. More...

#include <MeshSamplingTools.h>

Inheritance diagram for cloudViewer::MeshSamplingTools:

Collaboration diagram for cloudViewer::MeshSamplingTools:

Classes
struct	EdgeConnectivityStats
	Statistics on the edges connectivty of a mesh. More...

Public Types
enum	VertexFlags { VERTEX_NORMAL = 0 , VERTEX_BORDER = 1 , VERTEX_NON_MANIFOLD = 2 }
	Flags used by the MeshSamplingTools::flagMeshVerticesByType method. More...

Static Public Member Functions
static double	computeMeshArea (GenericMesh *mesh)
	Computes the mesh area. More...

static double	computeMeshVolume (GenericMesh *mesh)
	Computes the mesh volume. More...

static bool	computeMeshEdgesConnectivity (GenericIndexedMesh *mesh, EdgeConnectivityStats &stats)
	Computes some statistics on the edges connectivty of a mesh. More...

static bool	flagMeshVerticesByType (GenericIndexedMesh mesh, ScalarField flags, EdgeConnectivityStats *stats=nullptr)
	Flags the vertices of a mesh depending on their type. More...

static PointCloud *	samplePointsOnMesh (GenericMesh mesh, double samplingDensity, GenericProgressCallback progressCb=nullptr, std::vector< unsigned > *triIndices=nullptr)
	Samples points on a mesh. More...

static PointCloud *	samplePointsOnMesh (GenericMesh mesh, unsigned numberOfPoints, GenericProgressCallback progressCb=nullptr, std::vector< unsigned > *triIndices=nullptr)
	Samples points on a mesh. More...

Protected Types
using	EdgeUsageMap = std::map< unsigned long long, unsigned >
	Map used to count the number of triangles using each edge. More...

Static Protected Member Functions
static PointCloud *	samplePointsOnMesh (GenericMesh mesh, double samplingDensity, unsigned theoreticNumberOfPoints, GenericProgressCallback progressCb=nullptr, std::vector< unsigned > *triIndices=nullptr)
	Samples points on a mesh - internal method. More...

static unsigned long long	ComputeEdgeKey (unsigned i1, unsigned i2)
	Computes the unique key corresponding to an edge. More...

static void	DecodeEdgeKey (unsigned long long key, unsigned &i1, unsigned &i2)
	Computes the edge vertex indexes from its unique key. More...

static bool	buildMeshEdgeUsageMap (GenericIndexedMesh *mesh, EdgeUsageMap &edgeMap)
	Creates a map to count the number of triangles using each edge. More...

Detailed Description

Mesh sampling algorithms.

Definition at line 26 of file MeshSamplingTools.h.

Member Typedef Documentation

◆ EdgeUsageMap

using cloudViewer::MeshSamplingTools::EdgeUsageMap = std::map<unsigned long long, unsigned>

protected

Map used to count the number of triangles using each edge.

Edges are represented by two 32 bits indexes merged as a 64 integer

Definition at line 153 of file MeshSamplingTools.h.

Member Enumeration Documentation

◆ VertexFlags

enum cloudViewer::MeshSamplingTools::VertexFlags

Flags used by the MeshSamplingTools::flagMeshVerticesByType method.

Enumerator
VERTEX_NORMAL	Normal vertex
VERTEX_BORDER	Vertex on a border/hole
VERTEX_NON_MANIFOLD	Vertex on a non-manifold edge

Definition at line 73 of file MeshSamplingTools.h.

Member Function Documentation

◆ buildMeshEdgeUsageMap()

bool MeshSamplingTools::buildMeshEdgeUsageMap	(	GenericIndexedMesh *	mesh,
		EdgeUsageMap &	edgeMap
	)

staticprotected

Creates a map to count the number of triangles using each edge.

Definition at line 104 of file MeshSamplingTools.cpp.

References ComputeEdgeKey(), cloudViewer::GenericIndexedMesh::getNextTriangleVertIndexes(), cloudViewer::VerticesIndexes::i, cloudViewer::GenericMesh::placeIteratorAtBeginning(), and cloudViewer::GenericMesh::size().

Referenced by computeMeshEdgesConnectivity(), and flagMeshVerticesByType().

◆ ComputeEdgeKey()

unsigned long long MeshSamplingTools::ComputeEdgeKey	(	unsigned	i1,
		unsigned	i2
	)

staticprotected

Computes the unique key corresponding to an edge.

Definition at line 90 of file MeshSamplingTools.cpp.

References std::swap().

Referenced by buildMeshEdgeUsageMap().

◆ computeMeshArea()

double MeshSamplingTools::computeMeshArea ( GenericMesh * mesh )

static

Computes the mesh area.

Parameters

mesh	triangular mesh

Returns: mesh area

Definition at line 23 of file MeshSamplingTools.cpp.

References cloudViewer::GenericTriangle::_getA(), cloudViewer::GenericTriangle::_getB(), cloudViewer::GenericTriangle::_getC(), cloudViewer::GenericMesh::_getNextTriangle(), Vector3Tpl< Type >::cross(), Vector3Tpl< Type >::norm(), cloudViewer::GenericMesh::placeIteratorAtBeginning(), and cloudViewer::GenericMesh::size().

Referenced by ccComparisonDlg::determineBestOctreeLevel(), and samplePointsOnMesh().

◆ computeMeshEdgesConnectivity()

bool MeshSamplingTools::computeMeshEdgesConnectivity	(	GenericIndexedMesh *	mesh,
		EdgeConnectivityStats &	stats
	)

static

Computes some statistics on the edges connectivty of a mesh.

This methods counts the number of edges shared by 1, 2 or more faces. One ore more edges used only by 1 face each indicates the presence of at least one hole. Edges used by more than two faces are non-manifold.

Parameters

[in]	mesh	triangular mesh
[out]	stats	output statistics

Returns: false if an error occurred (invalid input or not enough memory)

Definition at line 133 of file MeshSamplingTools.cpp.

References buildMeshEdgeUsageMap(), cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesCount, cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesNotShared, cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesSharedByMore, and cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesSharedByTwo.

◆ computeMeshVolume()

double MeshSamplingTools::computeMeshVolume ( GenericMesh * mesh )

static

Computes the mesh volume.

Warning: Make sure the input mesh is closed! See MeshSamplingTools::computeMeshEdgesConnectivity.

Parameters

mesh	triangular mesh (closed!)

Returns: mesh volume

Definition at line 50 of file MeshSamplingTools.cpp.

References cloudViewer::GenericTriangle::_getA(), cloudViewer::GenericTriangle::_getB(), cloudViewer::GenericTriangle::_getC(), cloudViewer::GenericMesh::_getNextTriangle(), abs(), cloudViewer::GenericMesh::getBoundingBox(), cloudViewer::GenericMesh::placeIteratorAtBeginning(), cloudViewer::GenericMesh::size(), Tuple3Tpl< Type >::x, Tuple3Tpl< Type >::y, and Tuple3Tpl< Type >::z.

Referenced by CommandComputeMeshVolume::process().

◆ DecodeEdgeKey()

void MeshSamplingTools::DecodeEdgeKey	(	unsigned long long	key,
		unsigned &	i1,
		unsigned &	i2
	)

staticprotected

Computes the edge vertex indexes from its unique key.

Definition at line 97 of file MeshSamplingTools.cpp.

Referenced by flagMeshVerticesByType().

◆ flagMeshVerticesByType()

bool MeshSamplingTools::flagMeshVerticesByType	(	GenericIndexedMesh *	mesh,
		ScalarField *	flags,
		EdgeConnectivityStats *	stats = `nullptr`
	)

static

Flags the vertices of a mesh depending on their type.

See MeshSamplingTools::VertexFlags.

Parameters

[in]	mesh	triangular mesh
[in]	flags	already allocated scalar field to store the per-vertex flags
[out]	stats	output statistics (optional)

Returns: false if an error occurred (invalid input or not enough memory)

Definition at line 160 of file MeshSamplingTools.cpp.

References buildMeshEdgeUsageMap(), cloudViewer::ScalarField::computeMinAndMax(), cloudViewer::ScalarField::currentSize(), DecodeEdgeKey(), cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesCount, cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesNotShared, cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesSharedByMore, cloudViewer::MeshSamplingTools::EdgeConnectivityStats::edgesSharedByTwo, cloudViewer::ScalarField::fill(), NAN_VALUE, cloudViewer::ScalarField::setValue(), VERTEX_BORDER, VERTEX_NON_MANIFOLD, and VERTEX_NORMAL.

◆ samplePointsOnMesh() [1/3]

PointCloud * MeshSamplingTools::samplePointsOnMesh	(	GenericMesh *	mesh,
		double	samplingDensity,
		GenericProgressCallback *	progressCb = `nullptr`,
		std::vector< unsigned > *	triIndices = `nullptr`
	)

static

Samples points on a mesh.

The points are sampled on each triangle randomly, by generating two numbers between 0 and 1 (a and b). If a+b > 1, then a = 1-a and b = 1-b. Let ABC be the triangle, then the new point P will be as AP = a.AB+b.AC (AP,AB and AC are vectors here). The number of points sampled on each triangle depends on the triangle's area. Let s be this area, and µ the sampling density, then N = s*µ is the theoretic (floating) number of points to sample. The floating part of N (let's call it Nf, and let Ni be the integer part) is handled by generating another random number between 0 and 1. If this number is less than Nf, then Ni = Ni+1. The number of points sampled on the triangle will simply be Ni.

Parameters

	mesh	the mesh to be sampled
	samplingDensity	the sampling surface density
	progressCb	the client application can get some notification of the process progress through this callback mechanism (see GenericProgressCallback)
[out]	triIndices	triangle index for each samples point (output only - optional)

Returns: the sampled points

Definition at line 230 of file MeshSamplingTools.cpp.

References cloudViewer::utility::ceil(), and computeMeshArea().

Referenced by ccRegistrationTools::ICP(), and samplePointsOnMesh().

◆ samplePointsOnMesh() [2/3]

PointCloud * MeshSamplingTools::samplePointsOnMesh	(	GenericMesh *	mesh,
		double	samplingDensity,
		unsigned	theoreticNumberOfPoints,
		GenericProgressCallback *	progressCb = `nullptr`,
		std::vector< unsigned > *	triIndices = `nullptr`
	)

staticprotected

Samples points on a mesh - internal method.

See public methods descriptions

Parameters

	mesh	the mesh to be sampled
	samplingDensity	the sampling surfacical density
	theoreticNumberOfPoints	the approximated number of points that will be sampled
	progressCb	the client application can get some notification of the process progress through this callback mechanism (see GenericProgressCallback)
[out]	triIndices	triangle index for each samples point (output only - optional)

Returns: the sampled points

Definition at line 247 of file MeshSamplingTools.cpp.

◆ samplePointsOnMesh() [3/3]

PointCloud * MeshSamplingTools::samplePointsOnMesh	(	GenericMesh *	mesh,
		unsigned	numberOfPoints,
		GenericProgressCallback *	progressCb = `nullptr`,
		std::vector< unsigned > *	triIndices = `nullptr`
	)

static

Samples points on a mesh.

See the other version of this method. Instead of specifying a density, it is possible here to specify the total number of points to sample (approximative).

Parameters

	mesh	the mesh to be sampled
	numberOfPoints	the desired number of points on the whole mesh
	progressCb	the client application can get some notification of the process progress through this callback mechanism (see GenericProgressCallback)
[out]	triIndices	triangle index for each samples point (output only - optional)

Returns: the sampled points

Definition at line 211 of file MeshSamplingTools.cpp.

References computeMeshArea(), cloudViewer::LessThanEpsilon(), and samplePointsOnMesh().

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

/root/ACloudViewer/core/include/MeshSamplingTools.h
/root/ACloudViewer/core/src/MeshSamplingTools.cpp

Classes

Public Types

Static Public Member Functions

Protected Types

Static Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ EdgeUsageMap

Member Enumeration Documentation

◆ VertexFlags

Member Function Documentation

◆ buildMeshEdgeUsageMap()

◆ ComputeEdgeKey()

◆ computeMeshArea()

◆ computeMeshEdgesConnectivity()

◆ computeMeshVolume()

◆ DecodeEdgeKey()

◆ flagMeshVerticesByType()

◆ samplePointsOnMesh() [1/3]

◆ samplePointsOnMesh() [2/3]

◆ samplePointsOnMesh() [3/3]