CCCoreLib::MeshSamplingTools Class Reference

Mesh sampling algorithms. More...

#include <MeshSamplingTools.h>

Inheritance diagram for CCCoreLib::MeshSamplingTools:

Collaboration diagram for CCCoreLib::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.
static void	DecodeEdgeKey (unsigned long long key, unsigned &i1, unsigned &i2)
	Computes the edge vertex indexes from its unique key.
static bool	buildMeshEdgeUsageMap (GenericIndexedMesh *mesh, EdgeUsageMap &edgeMap)
	Creates a map to count the number of triangles using each edge.

Detailed Description

Mesh sampling algorithms.

Member Typedef Documentation

EdgeUsageMap

using CCCoreLib::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

Member Enumeration Documentation

VertexFlags

enum CCCoreLib::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

Member Function Documentation

computeMeshArea()

double MeshSamplingTools::computeMeshArea ( GenericMesh *  mesh )

static

Computes the mesh area.

Parameters

mesh	triangular mesh

Returns

mesh area

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 or 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)

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

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)

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

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

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

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

• MeshSamplingTools.h
• MeshSamplingTools.cpp