PentaGrow Class Reference

Detailed Description

Hybrid prismatic mesh generation.

PentaGrow generates a layer of pentahedral elements between a triangular surface mesh and an automatically constructed envelope surface placed at a suitable distance. It is meant to be used to quickly create meshes appropriate for the solution of the Reynolds-Averaged Navier-Stokes equations around aircraft configurations or similar geometries.

The algorithms are described in:

D. Eller, M. Tomac: "Implementation and evaluation of automated tetrahedral–prismatic mesh generation software." Computer-Aided Design, July 2015. doi:10.1016/j.cad.2015.06.010

See Also

MxMesh, TriMesh

#include <pentagrow.h>

Inheritance diagram for PentaGrow:

Collaboration diagram for PentaGrow:

Classes
class	ExtrusionTask
	Task for parallel extrusion of prismatic mesh grid. More...
class	UncollideTask
	Task for parallel resolution of indirect collisions. More...

Public Member Functions
	PentaGrow ()
	empty object
	PentaGrow (const TriMesh &m)
	initialize from wall mesh
void	configure (const ConfigParser &cfg)
	set configuration options
void	generateShell (int hiter, int niter, int ncrititer, int laplaceiter)
	generate the outermost layer
size_t	nWallNodes () const
	number of wall nodes
uint	extrude (bool curvedGrowth)
	extrude between wall and envelope, return prism layer mesh section index
void	adaptWall (const DVector< uint > &faceTags)
	adapt wall from refined outer shell (from tetgen)
void	readTets (const std::string &basename)
	read tetgen result and collect face tags
void	writeTetgen (const std::string &fname, const TriMesh &farf, const PointList< 3 > &holes, const TriMesh &refr=TriMesh(), Real nearBoxEdge=0.0)
	export boundaries to tetgen smesh file
void	shrink ()
	reduce memory footprint by erasing all working data (only raw mesh left)
size_t	countNegativeVolumes (std::ostream &msg)
	check volume elements in final mesh for positive volume
void	envelopeBounds (Vct3 &plo, Vct3 &phi) const
	compute bounding box of wall mesh
bool	ellipsoidEncloses (const Vct3 &ctr, const Vct3 &hax) const
	check whether axis-aligned ellipsoid encloses all envelope vertices
void	envelopeEdgeStats (Real &lmean, Real &lmax) const
	used to suggest near-field refinement factor: envelope edge lengths
Vector	prismQualitySumCos (const std::string &fname, uint isection, uint nbin=NotFound) const
	compute prism quality histogram and write to file
void	writeShell (const std::string &fname)
void	debugConnect ()
Public Member Functions inherited from MxMesh
uint	nelements () const
uint	nnodes () const
const Vct3 &	node (uint i) const
Vct3 &	node (uint i)
const PointList< 3 > &	nodes () const
PointList< 3 > &	nodes ()
uint	appendNode (const Vct3 &p)
uint	appendNodes (const PointList< 3 > &nds)
uint	appendNodes (NodeIter nbegin, NodeIter nend)
uint	nsections () const
const MxMeshSection &	section (uint i) const
MxMeshSection &	section (uint i)
uint	findSection (uint eix) const
uint	findSection (const std::string &sname) const
const uint *	globalElement (uint gix, uint &n, uint &isec) const
void	elementSections (const Indices &gix, ConnectMap &s2e) const
uint	appendSection (const MxMeshSection &ms)
uint	appendSection (Mx::ElementType t, const Indices &idx)
uint	appendSection (const TriMesh &m)
uint	appendSection (const PointGrid< 3 > &pg)
uint	appendSection (const PointList< 3 > &pts)
uint	appendSection (const CgMesh &cgm)
void	eraseSection (uint k)
uint	mirrorCopyNodes (const Indices &snodes, const Plane &pln)
uint	mirrorCopySection (uint k, uint voff, const Indices &snodes, bool merge=true)
uint	nbocos () const
const MxMeshBoco &	boco (uint i) const
MxMeshBoco &	boco (uint i)
uint	appendBoco (Mx::BocoType t, const Indices &idx)
uint	appendBoco (const MxMeshBoco &bc)
uint	appendBoco (MxMeshBoco &&bc)
void	eraseBoco (uint k)
void	clearBocos ()
uint	findBoco (const std::string &s) const
uint	mappedSection (uint iboco) const
uint	containedInSection (uint iboco) const
uint	nfields () const
uint	nDimFields (uint nd=3) const
const MxMeshField &	field (uint i) const
MxMeshField &	field (uint i)
void	bindFields ()
void	reserveFields (uint n)
uint	appendField (const MxMeshField &f)
uint	appendField (MxMeshField &&f)
uint	swapField (MxMeshField &f)
uint	appendField (const std::string &s, const Vector &v)
uint	appendField (const std::string &s, const DVector< float > &v)
uint	appendField (const std::string &s, const DVector< int > &v)
uint	appendField (const std::string &s, const PointList< 3 > &v)
uint	appendField (const std::string &s, const PointList< 3, float > &v)
uint	appendField (const std::string &s, const PointList< 6 > &v)
uint	appendField (const std::string &s, const PointList< 6, float > &v)
uint	appendRigidBodyMode (int mindex, const Vct3 &rotctr, Real gm=1.0, Real gk=0.0)
uint	findField (const std::string &s) const
void	findFields (int valClass, Indices &flds) const
void	eraseField (uint k)
void	clearFields ()
bool	generateMaxFields (bool useMaxAbs)
MxSolutionTreePtr	solutionTree () const
void	solutionTree (MxSolutionTreePtr p)
void	merge (const MxMesh &a, bool mergeFieldsByName)
uint	ndeform () const
const MxMeshDeform &	deform (uint i) const
MxMeshDeform &	deform (uint i)
void	eraseDeform (uint i)
uint	appendDeform (const MxMeshDeform &d)
uint	appendTrajectory (const std::string &fn, const Indices &useCols=Indices())
uint	appendFlutterMode (Complex p, const CpxVector &z, int nsample=32)
void	smoothTetNodes (uint npass=1, Real omega=0.5)
uint	planeCut (const Plane &p, Indices &ise) const
void	nodesBelow (const Plane &p, std::vector< bool > &nbelow) const
virtual void	reorder (const Indices &perm)
uint	dropUnusedNodes ()
uint	dropDegenerateElements ()
uint	mergeNodes (Real threshold=gmepsilon)
virtual bool	loadAny (const std::string &fname)
void	importMvz (const MeshFields &mvz)
TriMeshPtr	toTriMesh () const
CgMeshPtr	toCgMesh () const
void	writeAs (const std::string &fname, int fmt, int compression) const
void	writeSTL (const std::string &fname, bool binaryStl=false) const
void	writePLY (const std::string &fname, bool binary) const
void	writeSmesh (const std::string &fname, const PointList< 3 > &holes=PointList< 3 >(), const PointList< 3 > &regionMarkers=PointList< 3 >(), const Vector &regionAttr=Vector()) const
void	readTetgen (const std::string &basename, DVector< uint > *ftags=0)
void	readCgns (const std::string &fname)
void	writeCgns (const std::string &fname, bool bcAsSections=false) const
void	readAbaqus (const std::string &fname)
void	writeAbaqus (const std::string &fname) const
void	writeNastran (const std::string &fname, size_t nodeOffset=0, size_t eidOffset=0) const
void	writeNastran (std::ostream &os, size_t nodeOffset, size_t eidOffset) const
BinFileNodePtr	gbfNode (bool share=true) const
void	fromGbf (const BinFileNodePtr &np, bool digestNode=false)
virtual XmlElement	toXml (bool share=false) const
virtual void	fromXml (const XmlElement &xe)
void	writeZml (const std::string &fname, int compression=1) const
void	readZml (const std::string &fname)
XmlElement	toVTK () const
void	writeLegacyVtk (const std::string &fname) const
void	readLegacyVtk (const std::string &fname)
void	readAerel (const std::string &fname)
void	writeFFA (const std::string &fname) const
void	readFFA (const std::string &bmeshFile)
bool	appendFFAFields (const std::string &boutFile)
size_t	writeFieldsBdis (const std::string &basename) const
void	writeSU2 (const std::string &fname) const
void	readSU2 (const std::string &fname)
void	writeEnsight (const std::string &basename) const
void	readEnsight (const std::string &casename)
void	fakeNastran (const std::string &fname) const
void	countElements ()
void	fixate ()
const ConnectMap &	v2eMap () const
void	v2vMap (ConnectMap &v2v) const
void	e2eMap (ConnectMap &e2e) const
bool	containsNodesOf (uint e1, uint e2) const
uint	connectedComponents (Indices &ecmp, bool crossTypes=false) const
virtual void	clear ()
virtual float	megabytes () const
int	resetSectionColors (int hue, int sat=120, int val=140)
int	resetBocoColors (int hue, int sat=160, int val=170)
Public Member Functions inherited from MxAnnotated
	MxAnnotated (const MxAnnotated &)=default
	MxAnnotated (MxAnnotated &&a)
MxAnnotated &	operator= (const MxAnnotated &)=default
MxAnnotated &	operator= (MxAnnotated &&a)
void	note (const XmlElement &xe)
const XmlElement &	note () const
void	annotate (const XmlElement &xe)
XmlElement::const_iterator	noteBegin () const
XmlElement::const_iterator	noteEnd () const
void	attribute (const std::string &key, const std::string &value)
std::string	attribute (const std::string &key) const
Public Member Functions inherited from Logger
	Logger (const Logger &a)
Logger &	operator= (const Logger &a)
void	storeLogMessages (bool flag)
const std::vector< std::string > &	logMessages () const
virtual void	log (const std::string &s) const
void	log (const FirstType &a1, MoreTypes...as) const
void	reset ()
bool	increment (int step=1)
virtual bool	nextStage (int steps)
int	progress () const
int	nsteps () const
float	percentage () const
int	stage () const
void	interrupt (bool flag)
bool	interrupted () const

Static Public Member Functions
static int	maximumTagValue ()
	maximum permitted section tag value
static uint	maximumTriangleCount ()
	maximum permitted number of boundary triangles
Static Public Member Functions inherited from MxMesh
static uint	nElementNodes (Mx::ElementType t)

Private Types
enum	VertexCategory {   Undefined = 0, Concave = 1, Convex = 2, Conical = 4,   Corner = 8, Ridge = 16, StrongCurvature = 32, Sharp = 64,   Saddle = (Concave | Convex), ConcaveCorner = (Corner | Concave), ConvexCorner = (Corner | Convex), SaddleCorner = (Corner | Saddle),   ConeDipp = (Concave | Corner | Conical), ConeTip = (Convex | Corner | Conical), BluntCorner = (Corner|Saddle|Conical), Trench = (Ridge | Concave),   ConvexEdge = (Ridge | Convex), Wedge = (Ridge | Convex | Concave), RidgeConeTip = (Convex | Conical | Ridge), LeadingEdgeIntersection = (Trench | StrongCurvature),   TrailingEdgeIntersection = (SaddleCorner | Sharp), CriticalCorner = 512, Flat = 1024, Anything = -1 }

Private Member Functions
void	extractWall (const MxMesh &gm)
	extract wall from global mesh
void	classify ()
	classify and rank vertices
void	adjustRidgeNormals ()
	determine initial wall normals
bool	isClass (size_t i, int cat) const
	test whether a vertex is exactly of a certain category
bool	hasClass (size_t i, int cat) const
	test whether a vertex has at least a certain category
Real	convexity (const Vct3 &p1, const Vct3 &n1, const Vct3 &p2, const Vct3 &n2)
	test for convexity, returns positive values for convex features
Real	convexity (uint i1, uint i2)
	test for convexity, returns positive values for convex features
void	smoothThickness (Vector &lyt, int niter) const
	smooth thickness of prismatic layers
void	edgeLengthStats (uint k, Real &lmean, Real &lmax, Real &lmin) const
	compute wall mesh edge length statistics around node k
void	prismPattern (Real rhfirst, Real rhlast, Vector &xpp) const
	determine suitable normalized pattern for prism heights
Vct3	projectToWall (const TriMesh &mout, const Vct3 &pout, uint inear) const
	determine wall point for outer mesh point pout
Vct3	findWallVertex (const TriMesh &oldShell, const TriMesh &newShell, uint niShell) const
	determine corresponding wall mesh vertex
void	rebuildTree ()
	rebuild search tree using current set of outer-layer vertices
void	findNeighbors (const Vct3 &p, Real r, Indices &neighbors) const
	find all outer-layer nodes closer than r to p
bool	collisions (Indices &colliding, uint iwall, Real safety, Real nrmdev=cos(rad(60.)), Real fnrmdev=cos(rad(120.))) const
	find collision candidates using normal criterion
int	collisions (uint iwall, Real safety=1.2, Real nrmdev=cos(rad(60.)), Real fnrmdev=cos(rad(120.))) const
	just test for collisions using normal criterion, do not collect neighbors
uint32_t	extractSectionTag (uint32_t tag) const
	extract section tag from tetgen tag
uint32_t	extractElementTag (uint32_t tag) const
	extract element tag from tetgen tag
void	edgeMap (ConnectMap &map) const
	build vertex-to-vertex connectivity for the surface
template<class Container >
void	smooth (const ConnectMap &map, Container &c) const
	generalized nodal smoothing.
template<class Container , class WritePred , class ReadPred >
void	smooth (const ConnectMap &map, Container &c, const WritePred &writeNode, const ReadPred &readNode) const
	generalized nodal smoothing.
void	smoothShellNodes (const Vector &lyt, int niter, Real omega=0.5)
	Laplace smoothing of outer shell node coordinates.
Vct3	nbBarycenter (const PointList< 3 > &pts, size_t k) const
	compute barycenter of local neighborhood of node k
int	untangle (Vector &lyt, int niter, Real permitted_etwist)
	reduce edge twist
void	unwarp (int niter, Real permitted_angle)
	reduce penta warp
void	uncollide (int niter, Real safety, Real retraction, Real limitphi, Real limitphif)
	resolve indirect collisions
uint	uncollideVertex (uint i, Vector &lyt, Real safety, Real retraction, Real cphi, Real cphif)
	uncollide a single vertex (nucleus function for parallelization)
void	retractNeighbors (const Indices &afv, Vector &lyt, int ring=3)
	ring-2 smoothing of affected vertices in untangle/unwarp/uncollide
void	extrudeVertex (int ivx, int nl, Real hi, bool curvedGrowth, PointGrid< 3 > &grid) const
	extrude a single vertex (nucleaus for parallelization)
void	smoothWallTransition (int niter)
	optionally initialize, then distribute wall normal transition parameters
void	mergeNeighbors (Indices &idx) const
	augment a set of vertices with its direct neighbors
size_t	untangleGrid (PointGrid< 3 > &grid)
	attempt to untangle remaining tangled pentahedra
uint	appendPrismLayer (const PointGrid< 3 > &grid)
	add pentahedral elements to mesh, return mesh section index
void	updateShellNormals ()
	determine vertex normals for envelope
void	centerGridNodes (uint niter, PointGrid< 3 > &grid) const
	move grid vertices to the barycenter of their neighborhood
void	centerGridNodesPass (const PointGrid< 3 > &cgrid, PointGrid< 3 > &grid) const
	move grid vertices to the barycenter of their neighborhood, single pass
void	findEnvelopeNeighbors (Indices &interfaceNodes, Indices &nearTetNodes) const
	find nodes which are part of prismatic and tetrahedral region

Private Attributes
TriMesh	mwall
	wall mesh (must be watertight)
PointList< 3 >	wfn
	smoothed wall normals
PointList< 3 >	vout
	outermost layer
PointList< 3 >	envNormals
	vertex normals for outer layer
PointList< 3 >	fudir
	local wall coordinate system for optimization
PointList< 3 >	fvdir
Vector	targetHeight
	target height values for NLOPT
Vector	invGrowthExponent
	exponent factor for curved growth direction (0.0 -> straight)
DVector< int >	vtype
	integer flag indicating vertex category
DVector< int >	etype
	integer flag indicating mesh edge category
DVector< uint >	id2index
	maps triangle id passed to tetgen to original triangle index
DVector< uint >	id2section
	maps triangle id passed to tetgen to section index
Indices	wallTags
	mesh tags which contain wall boundary
Indices	farTags
NDPointTree< 3, float >	nodeTree
	search tree for nodes in the outer layer
std::vector< bool >	gridBaseTangled
	tags surface nodes which resulted in tangled grid nodes
Real	cosFeatureAngle
	Feature angle for geometrical identification.
Real	cosconcave
	Angle for concave/convex identification.
Real	cosSharpAngle
	cosine of angle limit for classification as sharp (default 150deg)
MxMeshSection	farfieldSection
	farfield section generated by adaptWall
Real	firstCellHeight
	configuration parameters
Real	maxRelHeight
Real	maxAbsHeight
Real	maxExpansionFactor
Real	maxOptimizationTime
	maximum time to be used by numerical optimization (default 30 seconds)
Real	defaultInvGrowthExp
	growth exponent factor : make this larger for improved wall-normality
int	numPrismLayers
	configuration parameters
bool	chattyOptimization
	whether to log function values during optimization
bool	attemptGridUntangling
	whether to attamept grid untangling or not (default - yes)

Additional Inherited Members
Protected Member Functions inherited from MxMesh
void	assembleVectorFields ()
virtual int	readTetgenNodes (std::istream &is)
virtual void	readTetgenFaces (std::istream &is, int offset, DVector< uint > *ptags=0)
virtual void	readTetgenElements (std::istream &is, int offset)
void	readFFARegion (const FFANode &node)
void	readFFABoundary (const FFANode &node)
MxSolutionTreePtr	appendSubcase (FFANodePtr pregion)
std::string	readAbaqusNodes (std::istream &in, DVector< int > &gid)
std::string	readAbaqusElements (const std::string &header, std::istream &in, DVector< int > &eid)
std::string	readAbaqusSet (const std::string &header, const DVector< int > &eid, std::istream &in)
std::string	readAbaqusKeyword (const std::string &header, std::istream &in, XmlElement &xabq)
MxSolutionTreePtr	generateMaxFields (MxSolutionTreePtr root, bool useMaxAbs)
Static Protected Member Functions inherited from MxMesh
static void	fileFloatPrecision (TypeCode tc)
Protected Attributes inherited from MxMesh
PointList< 3 >	vtx
std::vector< MxMeshSection >	sections
std::vector< MxMeshBoco >	bocos
std::vector< MxMeshField >	fields
std::vector< MxMeshDeform >	deforms
MxSolutionTreePtr	soltree
ConnectMap	v2e
std::string	meshName
uint	nelm
Protected Attributes inherited from MxAnnotated
XmlElement	xnote
Static Protected Attributes inherited from MxMesh
static TypeCode	s_fileFloatPrecision

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

• pentagrow.h (r6218/r5385)
• pentagrow.cpp (r6218/r5337)