Description

A triangle mesh with connectivity info: vertices can be shared between faces.

To keep this simple, the class assumes that you will manage the size of vectors m_vertices, m_normals etc., so ve cautious about resizing etc. We assume that

if no m_face_uv_indices but m_UV.size() == m_vertices.size(), then m_UV represents per-vertex UV, otherwise per-face-corner
if no m_face_col_indices but m_colors.size() == m_vertices.size(), then m_colors represents per-vertex colors, otherwise per-face-corner

#include <ChTriangleMeshConnected.h>

Inheritance diagram for chrono::ChTriangleMeshConnected:

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Collaboration diagram for chrono::ChTriangleMeshConnected:

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Classes
class	ChRefineEdgeCriterion
	Class to be used optionally in RefineMeshEdges(). More...

Public Member Functions
	ChTriangleMeshConnected (const ChTriangleMeshConnected &source)

virtual ChTriangleMeshConnected *	Clone () const override
	"Virtual" copy constructor (covariant return type).

std::vector< ChVector3d > &	GetCoordsVertices ()

std::vector< ChVector3d > &	GetCoordsNormals ()

std::vector< ChVector2d > &	GetCoordsUV ()

std::vector< ChColor > &	GetCoordsColors ()

std::vector< ChVector3i > &	GetIndicesVertexes ()

std::vector< ChVector3i > &	GetIndicesNormals ()

std::vector< ChVector3i > &	GetIndicesUV ()

std::vector< ChVector3i > &	GetIndicesColors ()

std::vector< int > &	GetIndicesMaterials ()

std::vector< ChProperty * > &	GetPropertiesPerVertex ()

std::vector< ChProperty * > &	GetPropertiesPerFace ()

const std::vector< ChVector3d > &	GetCoordsVertices () const

const std::vector< ChVector3d > &	GetCoordsNormals () const

const std::vector< ChVector2d > &	GetCoordsUV () const

const std::vector< ChColor > &	GetCoordsColors () const

const std::vector< ChVector3i > &	GetIndicesVertexes () const

const std::vector< ChVector3i > &	GetIndicesNormals () const

const std::vector< ChVector3i > &	GetIndicesUV () const

const std::vector< ChVector3i > &	GetIndicesColors () const

const std::vector< int > &	GetIndicesMaterials () const

void	AddPropertyPerVertex (ChProperty &mprop)
	Add a property as an array of data per-vertex. More...

void	AddPropertyPerFace (ChProperty &mprop)
	Add a property as an array of data per-face. More...

bool	LoadWavefrontMesh (const std::string &filename, bool load_normals=true, bool load_uv=false)
	Load a Wavefront OBJ file into this triangle mesh.

bool	LoadSTLMesh (const std::string &filename, bool load_normals=true)
	Load an STL file into this triangle mesh.

virtual void	AddTriangle (const ChVector3d &vertex0, const ChVector3d &vertex1, const ChVector3d &vertex2) override
	Add a triangle to this triangle mesh, by specifying the three coordinates. More...

virtual void	AddTriangle (const ChTriangle &atriangle) override
	Add a triangle to this triangle mesh, by specifying a ChTriangle.

unsigned int	GetNumVertices () const
	Get the number of vertices in this mesh.

unsigned int	GetNumNormals () const
	Get the number of normals in this mesh.

virtual unsigned int	GetNumTriangles () const override
	Get the number of triangles already added to this mesh.

virtual ChTriangle	GetTriangle (unsigned int index) const override
	Access the n-th triangle in mesh.

virtual void	Clear () override
	Clear all data.

virtual ChAABB	GetBoundingBox () const override
	Compute bounding box of this triangle mesh.

void	ComputeMassProperties (bool bodyCoords, double &mass, ChVector3d &center, ChMatrix33<> &inertia)
	Compute barycenter, mass, inertia tensor.

const std::string &	GetFileName () const
	Get the filename of the triangle mesh.

virtual void	Transform (const ChVector3d displ, const ChMatrix33<> rotscale) override
	Transform all vertexes, by displacing and rotating (rotation via matrix, so also scaling if needed).

bool	ComputeNeighbouringTriangleMap (std::vector< std::array< int, 4 >> &tri_map) const
	Create a map of neighboring triangles, vector [Ti TieA TieB TieC] (the free sides have triangle id = -1). More...

bool	ComputeWingedEdges (std::map< std::pair< int, int >, std::pair< int, int >> &winged_edges, bool allow_single_wing=true) const
	Create a winged edge structure, map of {key, value} as {{edgevertexA, edgevertexB}, {triangleA, triangleB}}. More...

int	RepairDuplicateVertexes (double tolerance=1e-18)
	Connect overlapping vertexes. More...

bool	MakeOffset (double offset)
	Offset the mesh, by a specified value, orthogonally to the faces. More...

std::pair< int, int >	GetTriangleEdgeIndexes (const ChVector3i &face_indices, int nedge, bool unique)
	Return the indexes of the two vertexes of the i-th edge of the triangle. More...

bool	SplitEdge (int itA, int itB, int neA, int neB, int &itA_1, int &itA_2, int &itB_1, int &itB_2, std::vector< std::array< int, 4 >> &tri_map, std::vector< std::vector< double > * > &aux_data_double, std::vector< std::vector< int > * > &aux_data_int, std::vector< std::vector< bool > * > &aux_data_bool, std::vector< std::vector< ChVector3d > * > &aux_data_vect)
	Split a given edge by inserting a vertex in the middle: from two triangles one gets four triangles. More...

void	RefineMeshEdges (std::vector< int > &marked_tris, double edge_maxlen, ChRefineEdgeCriterion criterion, std::vector< std::array< int, 4 >> atri_map, std::vector< std::vector< double > * > &aux_data_double, std::vector< std::vector< int > * > &aux_data_int, std::vector< std::vector< bool > * > &aux_data_bool, std::vector< std::vector< ChVector3d > * > &aux_data_vect)
	Performs mesh refinement using Rivara LEPP long-edge bisection algorithm. More...

const std::vector< ChVector3d > &	getFaceVertices ()

const std::vector< ChVector3d > &	getFaceNormals ()

const std::vector< ChColor > &	getFaceColors ()

const std::vector< ChVector3d > &	getAverageNormals ()

virtual Type	GetType () const override
	Get the class type as an enum.

virtual void	ArchiveOut (ChArchiveOut &archive_out) override
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIn (ChArchiveIn &archive_in) override
	Method to allow de-serialization of transient data from archives.

Public Member Functions inherited from chrono::ChTriangleMesh
virtual void	Transform (const ChVector3d displ, const ChQuaternion<> mquat=ChQuaternion<>(1, 0, 0, 0))
	Transform all vertexes, by displacing and rotating (rotation via matrix, so also scaling if needed)

virtual int	GetManifoldDimension () const override
	This is a surface.

Public Member Functions inherited from chrono::ChGeometry
	ChGeometry (const ChGeometry &other)

void	InflateBoundingBox (ChAABB &bbox) const
	Enlarge the given existing bounding box with the bounding box of this object.

virtual double	GetBoundingSphereRadius () const
	Returns the radius of a bounding sphere for this geometry. More...

virtual ChVector3d	Baricenter () const
	Compute center of mass.

virtual void	Update ()
	Generic update of internal data.

Static Public Member Functions
static std::shared_ptr< ChTriangleMeshConnected >	CreateFromWavefrontFile (const std::string &filename, bool load_normals=true, bool load_uv=false)
	Create and return a ChTriangleMeshConnected from a Wavefront OBJ file. More...

static std::shared_ptr< ChTriangleMeshConnected >	CreateFromSTLFile (const std::string &filename, bool load_normals=true)
	Create and return a ChTriangleMeshConnected from an STL file. More...

static void	WriteWavefront (const std::string &filename, const std::vector< ChTriangleMeshConnected > &meshes)
	Write the specified meshes in a Wavefront .obj file.

static ChTriangleMeshConnected	Merge (std::vector< ChTriangleMeshConnected > &meshes)
	Utility function for merging multiple meshes.

static ChAABB	GetBoundingBox (std::vector< ChVector3d > vertices)
	Return the bounding box of a triangle mesh with given vertices.

Public Attributes
std::vector< ChVector3d >	m_vertices

std::vector< ChVector3d >	m_normals

std::vector< ChVector2d >	m_UV

std::vector< ChColor >	m_colors

std::vector< ChVector3i >	m_face_v_indices

std::vector< ChVector3i >	m_face_n_indices

std::vector< ChVector3i >	m_face_uv_indices

std::vector< ChVector3i >	m_face_col_indices

std::vector< int >	m_face_mat_indices

std::string	m_filename
	file string if loading an obj file

std::vector< ChProperty * >	m_properties_per_vertex

std::vector< ChProperty * >	m_properties_per_face

std::vector< ChVector3d >	m_tmp_vectors

std::vector< ChColor >	m_tmp_colors

Additional Inherited Members
Public Types inherited from chrono::ChGeometry
enum	Type { NONE, SPHERE, ELLIPSOID, BOX, CYLINDER, TRIANGLE, CAPSULE, CONE, LINE, LINE_ARC, LINE_BEZIER, LINE_CAM, LINE_PATH, LINE_POLY, LINE_SEGMENT, ROUNDED_BOX, ROUNDED_CYLINDER, TRIANGLEMESH, TRIANGLEMESH_CONNECTED, TRIANGLEMESH_SOUP }
	Enumeration of geometric object types.

Member Function Documentation

◆ AddPropertyPerFace()

void chrono::ChTriangleMeshConnected::AddPropertyPerFace ( ChProperty & mprop )

inline

Add a property as an array of data per-face.

Deletion will be automatic at the end of mesh life. Warning: mprop.data.size() must be equal to m_vertices.size(). Cost: allocation a data copy.

◆ AddPropertyPerVertex()

void chrono::ChTriangleMeshConnected::AddPropertyPerVertex ( ChProperty & mprop )

inline

Add a property as an array of data per-vertex.

Deletion will be automatic at the end of mesh life. Warning: mprop.data.size() must be equal to m_vertices.size(). Cost: allocation and a data copy.

◆ AddTriangle()

void chrono::ChTriangleMeshConnected::AddTriangle	(	const ChVector3d &	vertex0,
		const ChVector3d &	vertex1,
		const ChVector3d &	vertex2
	)

overridevirtual

Add a triangle to this triangle mesh, by specifying the three coordinates.

This is disconnected - no vertex sharing is used even if it could be.

Implements chrono::ChTriangleMesh.

◆ ComputeNeighbouringTriangleMap()

bool chrono::ChTriangleMeshConnected::ComputeNeighbouringTriangleMap ( std::vector< std::array< int, 4 >> & tri_map ) const

Create a map of neighboring triangles, vector [Ti TieA TieB TieC] (the free sides have triangle id = -1).

Return false if some edge has more than 2 neighboring triangles

◆ ComputeWingedEdges()

bool chrono::ChTriangleMeshConnected::ComputeWingedEdges	(	std::map< std::pair< int, int >, std::pair< int, int >> &	winged_edges,
		bool	allow_single_wing = `true`
	)		const

Create a winged edge structure, map of {key, value} as {{edgevertexA, edgevertexB}, {triangleA, triangleB}}.

If allow_single_wing = false, only edges with at least 2 triangles are returned. Else, also boundary edges with 1 triangle (the free side has triangle id = -1). Return false if some edge has more than 2 neighboring triangles.

◆ CreateFromSTLFile()

std::shared_ptr< ChTriangleMeshConnected > chrono::ChTriangleMeshConnected::CreateFromSTLFile	(	const std::string &	filename,
		bool	load_normals = `true`
	)

static

Create and return a ChTriangleMeshConnected from an STL file.

If an error occurrs during loading, an empty shared pointer is returned.

◆ CreateFromWavefrontFile()

std::shared_ptr< ChTriangleMeshConnected > chrono::ChTriangleMeshConnected::CreateFromWavefrontFile	(	const std::string &	filename,
		bool	load_normals = `true`,
		bool	load_uv = `false`
	)

static

Create and return a ChTriangleMeshConnected from a Wavefront OBJ file.

If an error occurrs during loading, an empty shared pointer is returned.

◆ GetTriangleEdgeIndexes()

std::pair< int, int > chrono::ChTriangleMeshConnected::GetTriangleEdgeIndexes	(	const ChVector3i &	face_indices,
		int	nedge,
		bool	unique
	)

Return the indexes of the two vertexes of the i-th edge of the triangle.

If unique=true, swap the pair so that 1st < 2nd, to permit test sharing with other triangle.

Parameters

face_indices	indices of a triangular face
nedge	number of edge: 0, 1, 2
unique	swap?

◆ MakeOffset()

bool chrono::ChTriangleMeshConnected::MakeOffset ( double offset )

Offset the mesh, by a specified value, orthogonally to the faces.

The offset can be inward or outward. Note: self-collisions and inverted faces resulting from excessive offsets are NOT trimmed; so this is mostly meant to be a fast tool for making small offsets.

◆ RefineMeshEdges()

void chrono::ChTriangleMeshConnected::RefineMeshEdges	(	std::vector< int > &	marked_tris,
		double	edge_maxlen,
		ChRefineEdgeCriterion *	criterion,
		std::vector< std::array< int, 4 >> *	atri_map,
		std::vector< std::vector< double > * > &	aux_data_double,
		std::vector< std::vector< int > * > &	aux_data_int,
		std::vector< std::vector< bool > * > &	aux_data_bool,
		std::vector< std::vector< ChVector3d > * > &	aux_data_vect
	)

Performs mesh refinement using Rivara LEPP long-edge bisection algorithm.

Given a conforming, non-degenerate triangulation, it construct a locally refined triangulation with a prescribed resolution. This algorithm, for increasing resolution, tends to produce triangles with bounded angles even if starting from skewed/skinny triangles in the coarse mesh. Based on "Multithread parallelization of Lepp-bisection algorithms" M.-C. Rivara et al., Applied Numerical Mathematics 62 (2012) 473�488 The auxiliary buffers are used for refinement and assumed to be indexed like the vertex buffer.

Parameters

marked_tris	indexes of triangles to refine (also surrounding triangles might be affected by refinements)
edge_maxlen	maximum length of edge (small values give higher resolution)
criterion	criterion for computing lenght (or other merit function) of edge, if null uses default (euclidean length)
atri_map	optional triangle connectivity map
aux_data_double	auxiliary buffer
aux_data_int	auxiliary buffer
aux_data_bool	auxiliary buffer
aux_data_vect	auxiliary buffer

◆ RepairDuplicateVertexes()

int chrono::ChTriangleMeshConnected::RepairDuplicateVertexes ( double tolerance = 1e-18 )

Connect overlapping vertexes.

This can beused to attempt to repair a mesh with 'open edges' to transform it into a watertight mesh. Say, if a cube is modeled with 6 faces with 4 distinct vertexes each, it might display properly, but for some algorithms, ex. collision detection, topological information might be needed, hence adjacent faces must be connected. Return the number of merged vertexes.

Parameters

tolerance ignore vertexes closer than this value

◆ SplitEdge()

bool chrono::ChTriangleMeshConnected::SplitEdge	(	int	itA,
		int	itB,
		int	neA,
		int	neB,
		int &	itA_1,
		int &	itA_2,
		int &	itB_1,
		int &	itB_2,
		std::vector< std::array< int, 4 >> &	tri_map,
		std::vector< std::vector< double > * > &	aux_data_double,
		std::vector< std::vector< int > * > &	aux_data_int,
		std::vector< std::vector< bool > * > &	aux_data_bool,
		std::vector< std::vector< ChVector3d > * > &	aux_data_vect
	)

Split a given edge by inserting a vertex in the middle: from two triangles one gets four triangles.

It also interpolate normals, colors, uv. It also used and modifies the triangle neighboring map. If the two triangles do not share an edge, returns false. The auxiliary buffers are used for interpolation and assumed to be indexed like the vertex buffer.

Parameters

itA	triangle A index,
itB	triangle B index, -1 if not present (free edge on A)
neA	n.edge on tri A: 0,1,2
neB	n.edge on tri B: 0,1,2
itA_1	returns the index of split triangle A, part1
itA_2	returns the index of split triangle A, part2
itB_1	returns the index of split triangle B, part1
itB_2	returns the index of split triangle B, part2
tri_map	triangle neighbouring map
aux_data_double	auxiliary buffers
aux_data_int	auxiliary buffers
aux_data_bool	auxiliary buffers
aux_data_vect	auxiliary buffers

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

/builds/uwsbel/chrono/src/chrono/geometry/ChTriangleMeshConnected.h
/builds/uwsbel/chrono/src/chrono/geometry/ChTriangleMeshConnected.cpp

Description

Classes

Public Member Functions

Static Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

◆ AddPropertyPerFace()

◆ AddPropertyPerVertex()

◆ AddTriangle()

◆ ComputeNeighbouringTriangleMap()

◆ ComputeWingedEdges()

◆ CreateFromSTLFile()

◆ CreateFromWavefrontFile()

◆ GetTriangleEdgeIndexes()

◆ MakeOffset()

◆ RefineMeshEdges()

◆ RepairDuplicateVertexes()

◆ SplitEdge()