Description

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

#include <ChTriangleMeshConnected.h>

Inheritance diagram for chrono::geometry::ChTriangleMeshConnected:

Collaboration diagram for chrono::geometry::ChTriangleMeshConnected:

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< ChVector< double > > &	getCoordsVertices ()

std::vector< ChVector< double > > &	getCoordsNormals ()

std::vector< ChVector< double > > &	getCoordsUV ()

std::vector< ChVector< float > > &	getCoordsColors ()

std::vector< ChVector< int > > &	getIndicesVertexes ()

std::vector< ChVector< int > > &	getIndicesNormals ()

std::vector< ChVector< int > > &	getIndicesUV ()

std::vector< ChVector< int > > &	getIndicesColors ()

void	LoadWavefrontMesh (std::string filename, bool load_normals=true, bool load_uv=false)
	Load a triangle mesh saved as a Wavefront .obj file.

virtual void	addTriangle (const ChVector<> &vertex0, const ChVector<> &vertex1, const ChVector<> &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.

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

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

virtual void	Clear () override
	Clear all data.

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

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

virtual void	Transform (const ChVector<> 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 of: [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}} If allow_single_wing = false, only edges with at least 2 triangles are returned. More...

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

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

std::pair< int, int >	GetTriangleEdgeIndexes (const std::vector< ChVector< int >> &indexes, int it, 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< ChVector<>> * > &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< ChVector<>> * > &aux_data_vect)
	Performs mesh refinement using Rivara LEPP long-edge bisection algorithm. More...

virtual GeometryType	GetClassType () const override
	Get the class type as unique numerical ID (faster than using ChronoRTTI mechanism). More...

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

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

Public Member Functions inherited from chrono::geometry::ChTriangleMesh
virtual void	Transform (const ChVector<> 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 void	GetBoundingBox (double &xmin, double &xmax, double &ymin, double &ymax, double &zmin, double &zmax, ChMatrix33<> *Rot=NULL) const override
	Compute bounding box. More...

virtual void	CovarianceMatrix (ChMatrix33<> &C) const override
	Compute the 3x3 covariance matrix (only the diagonal and upper part) It should be overridden by inherited classes.

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

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

virtual void	InflateBoundingBox (double &xmin, double &xmax, double &ymin, double &ymax, double &zmin, double &zmax, ChMatrix33<> *Rot=NULL) const
	Enlarge a previous existing bounding box. More...

virtual double	Size () const
	Returns the radius of the sphere which can enclose the geometry.

virtual ChVector	Baricenter () const
	Compute center of mass It should be overridden by inherited classes.

virtual void	Update ()
	Generic update of internal data. More...

Static Public Member Functions
static void	WriteWavefront (const std::string &filename, 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.

Public Attributes
std::vector< ChVector< double > >	m_vertices

std::vector< ChVector< double > >	m_normals

std::vector< ChVector< double > >	m_UV

std::vector< ChVector< float > >	m_colors

std::vector< ChVector< int > >	m_face_v_indices

std::vector< ChVector< int > >	m_face_n_indices

std::vector< ChVector< int > >	m_face_uv_indices

std::vector< ChVector< int > >	m_face_col_indices

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

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

Member Function Documentation

◆ addTriangle()

virtual void chrono::geometry::ChTriangleMeshConnected::addTriangle	(	const ChVector<> &	vertex0,
		const ChVector<> &	vertex1,
		const ChVector<> &	vertex2
	)

inlineoverridevirtual

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::geometry::ChTriangleMesh.

◆ ComputeNeighbouringTriangleMap()

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

Create a map of neighboring triangles, vector of: [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::geometry::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.

◆ GetClassType()

virtual GeometryType chrono::geometry::ChTriangleMeshConnected::GetClassType ( ) const

inlineoverridevirtual

Get the class type as unique numerical ID (faster than using ChronoRTTI mechanism).

Each inherited class must return an unique ID.

Reimplemented from chrono::geometry::ChTriangleMesh.

◆ GetTriangleEdgeIndexes()

std::pair< int, int > chrono::geometry::ChTriangleMeshConnected::GetTriangleEdgeIndexes	(	const std::vector< ChVector< int >> &	indexes,
		int	it,
		int	nedge,
		bool	unique
	)

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

Parameters

indexes	indexes, xyz per each face, ex. getIndicesVertexes()
it	triangle index
nedge	number of edge: 0,1,2
unique	if true, swaps the pair so that 1st is always < 2nd id, so can test sharing wiht other triangle

◆ MakeOffset()

bool chrono::geometry::ChTriangleMeshConnected::MakeOffset ( const 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::geometry::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< ChVector<>> * > &	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

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 =0 uses default (euclidean length)
atri_map	triangle connectivity map: use and modify it. Optional. If =0, creates a temporary one just for life span of function.
aux_data_double	auxiliary buffers to refine (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_int	auxiliary buffers to refine (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_bool	auxiliary buffers to refine (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_vect	auxiliary buffers to refine (assuming indexed as vertexes: each with same size as vertex buffer)

◆ RepairDuplicateVertexes()

int chrono::geometry::ChTriangleMeshConnected::RepairDuplicateVertexes ( const 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 when vertexes are closer than this value, they are merged

◆ SplitEdge()

bool chrono::geometry::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< ChVector<>> * > &	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.

Parameters

itA	triangle A index,
itB	triangle B index, -1 if not existing (means 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 to interpolate (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_int	auxiliary buffers to interpolate (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_bool	auxiliary buffers to interpolate (assuming indexed as vertexes: each with same size as vertex buffer)
aux_data_vect	auxiliary buffers to interpolate (assuming indexed as vertexes: each with same size as vertex buffer)

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

◆ addTriangle()

◆ ComputeNeighbouringTriangleMap()

◆ ComputeWingedEdges()

◆ GetClassType()

◆ GetTriangleEdgeIndexes()

◆ MakeOffset()

◆ RefineMeshEdges()

◆ RepairDuplicateVertexes()

◆ SplitEdge()