Project edge mid-nodes onto a fine surface mesh using closest points. More...

#include "src/approximation/Projection10NodeCoordsOnField.hpp"

Inheritance diagram for MoFEM::Projection10NodeCoordsFromFineSurfaceOnField:

Collaboration diagram for MoFEM::Projection10NodeCoordsFromFineSurfaceOnField:

Public Member Functions
	Projection10NodeCoordsFromFineSurfaceOnField (Interface &m_field, moab::Interface &fine_moab, const Range &fine_tris, std::string field_name, double planar_angle_deg=5.0, double max_disp_factor=0.5, bool debug_surfaces=false, int verb=0)

MoFEMErrorCode	preProcess ()
	Pre-processing function executed at loop initialization.

MoFEMErrorCode	operator() ()
	Main operator function executed for each loop iteration.

MoFEMErrorCode	postProcess ()
	Post-processing function executed at loop completion.

Public Member Functions inherited from MoFEM::EntityMethod
MoFEMErrorCode	query_interface (boost::typeindex::type_index type_index, UnknownInterface **iface) const
	Query interface for type casting.

	EntityMethod ()=default
	Default constructor.

Public Member Functions inherited from MoFEM::BasicMethod
	BasicMethod ()
	Default constructor.

virtual	~BasicMethod ()=default
	Virtual destructor.

int	getNinTheLoop () const
	Get current loop iteration index.

int	getLoopSize () const
	Get total loop size.

auto	getLoHiFERank () const
	Get processor rank range for finite element iteration.

auto	getLoFERank () const
	Get lower processor rank for finite element iteration.

auto	getHiFERank () const
	Get upper processor rank for finite element iteration.

unsigned int	getFieldBitNumber (std::string field_name) const
	Get bit number for a specific field by name.

MoFEMErrorCode	copyBasicMethod (const BasicMethod &basic)
	Copy data from another BasicMethod instance.

boost::weak_ptr< CacheTuple >	getCacheWeakPtr () const
	Get the cache weak pointer object.

Public Member Functions inherited from MoFEM::KspMethod
MoFEMErrorCode	query_interface (boost::typeindex::type_index type_index, UnknownInterface **iface) const
	Query interface for type casting.

	KspMethod ()
	Default constructor.

virtual	~KspMethod ()=default
	Virtual destructor.

MoFEMErrorCode	copyKsp (const KspMethod &ksp)
	Copy data from another KSP method.

Public Member Functions inherited from MoFEM::PetscData
	PetscData ()
	Default constructor.

virtual	~PetscData ()=default
	Virtual destructor.

MoFEMErrorCode	copyPetscData (const PetscData &petsc_data)
	Copy PETSc data from another instance.

Public Member Functions inherited from MoFEM::UnknownInterface
template<class IFACE >
MoFEMErrorCode	registerInterface (bool error_if_registration_failed=true)
	Register interface.

template<class IFACE >
MoFEMErrorCode	getInterface (IFACE *&iface) const
	Get interface reference to pointer of interface.

template<class IFACE >
MoFEMErrorCode	getInterface (IFACE **const iface) const
	Get interface pointer to pointer of interface.

template<class IFACE , typename boost::enable_if< boost::is_pointer< IFACE >, int >::type = 0>
IFACE	getInterface () const
	Get interface pointer to pointer of interface.

template<class IFACE , typename boost::enable_if< boost::is_reference< IFACE >, int >::type = 0>
IFACE	getInterface () const
	Get reference to interface.

template<class IFACE >
IFACE *	getInterface () const
	Function returning pointer to interface.

virtual	~UnknownInterface ()=default

Public Member Functions inherited from MoFEM::SnesMethod
MoFEMErrorCode	query_interface (boost::typeindex::type_index type_index, UnknownInterface **iface) const
	Query interface for type casting.

	SnesMethod ()
	Default constructor.

virtual	~SnesMethod ()=default
	Virtual destructor.

MoFEMErrorCode	copySnes (const SnesMethod &snes)
	Copy SNES data from another instance.

Public Member Functions inherited from MoFEM::TSMethod
MoFEMErrorCode	query_interface (boost::typeindex::type_index type_index, UnknownInterface **iface) const
	Query interface for type casting.

	TSMethod ()
	Default constructor.

virtual	~TSMethod ()=default
	Virtual destructor.

MoFEMErrorCode	copyTs (const TSMethod &ts)
	Copy TS solver data from another instance.

Public Member Functions inherited from MoFEM::TaoMethod
MoFEMErrorCode	query_interface (boost::typeindex::type_index type_index, UnknownInterface **iface) const
	Query interface for type casting.

	TaoMethod ()
	Default constructor.

virtual	~TaoMethod ()=default
	Virtual destructor.

MoFEMErrorCode	copyTao (const TaoMethod &tao)
	Copy TAO data from another instance.

Protected Member Functions
	FTENSOR_INDEX (3, i)

	FTENSOR_INDEX (3, j)

Protected Attributes
Interface &	mField

moab::Interface &	fineMoab

Range	fineTris

std::string	fieldName

int	vErbose

AdaptiveKDTree	fineTree

EntityHandle	fineRoot

AdaptiveKDTree	fineFeatureTree

EntityHandle	fineFeatureRoot

Range	fineFeatureTris

double	planarAngleCos

double	maxDispFactor

bool	debugSurfaces

Range	coarseSkinTris

Range	coarseSkinEdges

VectorDouble	coords

VectorDouble3	aveMidCoord

VectorDouble3	midNodeCoord

VectorDouble3	diffNodeCoord

VectorDouble3	dOf

Additional Inherited Members
Public Types inherited from MoFEM::KspMethod
enum	KSPContext { CTX_SETFUNCTION , CTX_OPERATORS , CTX_KSPNONE }
	Context enumeration for KSP solver phases. More...

Public Types inherited from MoFEM::PetscData
enum	DataContext { CTX_SET_NONE = 0 , CTX_SET_F = 1 << 0 , CTX_SET_A = 1 << 1 , CTX_SET_B = 1 << 2 , CTX_SET_X = 1 << 3 , CTX_SET_DX = 1 << 4 , CTX_SET_X_T = 1 << 5 , CTX_SET_X_TT = 1 << 6 , CTX_SET_TIME = 1 << 7 }
	Enumeration for data context flags. More...

using	Switches = std::bitset< 8 >
	Bitset type for context switches.

Public Types inherited from MoFEM::SnesMethod
enum	SNESContext { CTX_SNESSETFUNCTION , CTX_SNESSETJACOBIAN , CTX_SNESNONE }
	Context enumeration for SNES solver phases. More...

Public Types inherited from MoFEM::TSMethod
enum	TSContext { CTX_TSSETRHSFUNCTION , CTX_TSSETRHSJACOBIAN , CTX_TSSETIFUNCTION , CTX_TSSETIJACOBIAN , CTX_TSTSMONITORSET , CTX_TSNONE }
	Context enumeration for TS solver phases. More...

Public Types inherited from MoFEM::TaoMethod
enum	TAOContext { CTX_TAO_OBJECTIVE , CTX_TAO_GRADIENT , CTX_TAO_HESSIAN , CTX_TAO_NONE }
	Context enumeration for TAO solver phases. More...

Static Public Member Functions inherited from MoFEM::UnknownInterface
static MoFEMErrorCode	getLibVersion (Version &version)
	Get library version.

static MoFEMErrorCode	getFileVersion (moab::Interface &moab, Version &version)
	Get database major version.

static MoFEMErrorCode	setFileVersion (moab::Interface &moab, Version version=Version(MoFEM_VERSION_MAJOR, MoFEM_VERSION_MINOR, MoFEM_VERSION_BUILD))
	Get database major version.

static MoFEMErrorCode	getInterfaceVersion (Version &version)
	Get database major version.

Public Attributes inherited from MoFEM::EntityMethod
boost::shared_ptr< Field >	fieldPtr
	Shared pointer to field information.

boost::shared_ptr< FieldEntity >	entPtr
	Shared pointer to field entity data.

Public Attributes inherited from MoFEM::BasicMethod
int	nInTheLoop
	Current index of processed method in the loop.

int	loopSize
	Total number of methods to process in the loop.

std::pair< int, int >	loHiFERank
	Processor rank range for distributed finite element iteration.

int	rAnk
	Current processor rank in MPI communicator.

int	sIze
	Total number of processors in MPI communicator.

const RefEntity_multiIndex *	refinedEntitiesPtr
	Pointer to container of refined MoFEM DOF entities.

const RefElement_multiIndex *	refinedFiniteElementsPtr
	Pointer to container of refined finite element entities.

const Problem *	problemPtr
	Raw pointer to current MoFEM problem instance.

const Field_multiIndex *	fieldsPtr
	Raw pointer to fields multi-index container.

const FieldEntity_multiIndex *	entitiesPtr
	Raw pointer to container of field entities.

const DofEntity_multiIndex *	dofsPtr
	Raw pointer to container of degree of freedom entities.

const FiniteElement_multiIndex *	finiteElementsPtr
	Raw pointer to container of finite elements.

const EntFiniteElement_multiIndex *	finiteElementsEntitiesPtr
	Raw pointer to container of finite element entities.

const FieldEntityEntFiniteElementAdjacencyMap_multiIndex *	adjacenciesPtr
	Raw pointer to container of adjacencies between DOFs and finite elements.

boost::function< MoFEMErrorCode()>	preProcessHook
	Hook function for pre-processing operations.

boost::function< MoFEMErrorCode()>	postProcessHook
	Hook function for post-processing operations.

boost::function< MoFEMErrorCode()>	operatorHook
	Hook function for main operator execution.

boost::movelib::unique_ptr< bool >	vecAssembleSwitch
	Switch for vector assembly operations.

boost::movelib::unique_ptr< bool >	matAssembleSwitch
	Switch for matrix assembly operations.

boost::weak_ptr< CacheTuple >	cacheWeakPtr
	Weak pointer to cached entity data.

Public Attributes inherited from MoFEM::KspMethod
KSPContext	ksp_ctx
	Current KSP computation context.

KSP	ksp
	PETSc KSP linear solver object.

Vec &	ksp_f
	Reference to residual vector in KSP context.

Mat &	ksp_A
	Reference to system matrix in KSP context.

Mat &	ksp_B
	Reference to preconditioner matrix in KSP context.

Public Attributes inherited from MoFEM::PetscData
Switches	data_ctx
	Current data context switches.

Vec	f
	PETSc residual vector.

Mat	A
	PETSc Jacobian matrix.

Mat	B
	PETSc preconditioner matrix.

Vec	x
	PETSc solution vector.

Vec	dx
	PETSc solution increment vector.

Vec	x_t
	PETSc first time derivative vector.

Vec	x_tt
	PETSc second time derivative vector.

Public Attributes inherited from MoFEM::SnesMethod
SNESContext	snes_ctx
	Current SNES computation context.

SNES	snes
	PETSc SNES nonlinear solver object.

Vec &	snes_x
	Reference to current solution state vector.

Vec &	snes_dx
	Reference to solution update/increment vector.

Vec &	snes_f
	Reference to residual vector.

Mat &	snes_A
	Reference to Jacobian matrix.

Mat &	snes_B
	Reference to preconditioner of Jacobian matrix.

Public Attributes inherited from MoFEM::TSMethod
TS	ts
	PETSc time stepping solver object.

TSContext	ts_ctx
	Current TS computation context.

PetscInt	ts_step
	Current time step number.

PetscReal	ts_a
	Shift parameter for U_t (see PETSc Time Solver documentation)

PetscReal	ts_aa
	Shift parameter for U_tt (second time derivative)

PetscReal	ts_t
	Current time value.

PetscReal	ts_dt
	Current time step size.

Vec &	ts_u
	Reference to current state vector U(t)

Vec &	ts_u_t
	Reference to first time derivative of state vector dU/dt.

Vec &	ts_u_tt
	Reference to second time derivative of state vector d²U/dt²

Vec &	ts_F
	Reference to residual vector F(t,U,U_t,U_tt)

Mat &	ts_A
	Reference to Jacobian matrix: dF/dU + adF/dU_t + aadF/dU_tt.

Mat &	ts_B
	Reference to preconditioner matrix for ts_A.

Public Attributes inherited from MoFEM::TaoMethod
TAOContext	tao_ctx
	Current TAO computation context.

Tao	tao
	PETSc TAO optimization solver object.

Vec &	tao_x
	Reference to optimization variables vector.

Vec &	tao_f
	Reference to gradient vector.

Mat &	tao_A
	Reference to Hessian matrix.

Mat &	tao_B
	Reference to preconditioner matrix for Hessian.

Static Public Attributes inherited from MoFEM::PetscData
static constexpr Switches	CtxSetNone = PetscData::Switches(CTX_SET_NONE)
	No data switch.

static constexpr Switches	CtxSetF = PetscData::Switches(CTX_SET_F)
	Residual vector switch.

static constexpr Switches	CtxSetA = PetscData::Switches(CTX_SET_A)
	Jacobian matrix switch.

static constexpr Switches	CtxSetB = PetscData::Switches(CTX_SET_B)
	Preconditioner matrix switch.

static constexpr Switches	CtxSetX = PetscData::Switches(CTX_SET_X)
	Solution vector switch.

static constexpr Switches	CtxSetDX = PetscData::Switches(CTX_SET_DX)
	Solution increment switch.

static constexpr Switches	CtxSetX_T = PetscData::Switches(CTX_SET_X_T)
	First time derivative switch.

static constexpr Switches	CtxSetX_TT = PetscData::Switches(CTX_SET_X_TT)
	Second time derivative switch.

static constexpr Switches	CtxSetTime = PetscData::Switches(CTX_SET_TIME)
	Time value switch.

Detailed Description

Project edge mid-nodes onto a fine surface mesh using closest points.

Definition at line 51 of file Projection10NodeCoordsOnField.hpp.

Constructor & Destructor Documentation

◆ Projection10NodeCoordsFromFineSurfaceOnField()

MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::Projection10NodeCoordsFromFineSurfaceOnField	(	Interface &	m_field,
		moab::Interface &	fine_moab,
		const Range &	fine_tris,
		std::string	field_name,
		double	planar_angle_deg = `5.0`,
		double	max_disp_factor = `0.5`,
		bool	debug_surfaces = `false`,
		int	verb = `0`
	)

Definition at line 194 of file Projection10NodeCoordsOnField.cpp.

    : mField(m_field), fineMoab(fine_moab), fineTris(fine_tris),
      fieldName(field_name), vErbose(verb), fineTree(&fine_moab), fineRoot(0),
      fineFeatureTree(&fine_moab), fineFeatureRoot(0),
      planarAngleCos(std::cos(planar_angle_deg * 0.017453292519943295)),
      maxDispFactor(max_disp_factor), debugSurfaces(debug_surfaces) {}

Member Function Documentation

◆ FTENSOR_INDEX() [1/2]

MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::FTENSOR_INDEX	(	3	,
		i
	)

protected

◆ FTENSOR_INDEX() [2/2]

MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::FTENSOR_INDEX	(	3	,
		j
	)

protected

◆ operator()()

MoFEMErrorCode MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::operator() ( )

virtual

Main operator function executed for each loop iteration.

This virtual function is called for every item (finite element, entity, etc.) in the loop. It is the core computation function typically used for:

Calculating element local matrices and vectors
Assembling contributions to global system
Element-level post-processing operations

Returns: Error code indicating success or failure

Reimplemented from MoFEM::BasicMethod.

Definition at line 302 of file Projection10NodeCoordsOnField.cpp.

                                                                        {
  MoFEMFunctionBeginHot;
 
  if (entPtr == NULL) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY, "data inconsistency");
  }
  if (entPtr->getName() != fieldName)
    MoFEMFunctionReturnHot(0);
  if (entPtr->getEntType() != MBEDGE)
    MoFEMFunctionReturnHot(0);
 
  const EntityHandle edge = entPtr->getEnt();
  if (coarseSkinEdges.find(edge) == coarseSkinEdges.end()) {
    MoFEMFunctionReturnHot(0);
  }
 
  Range adj_tris;
  CHKERR mField.get_moab().get_adjacencies(&edge, 1, 2, false, adj_tris,
                                          moab::Interface::UNION);
  adj_tris = intersect(adj_tris, coarseSkinTris);
  if (adj_tris.size() != 2) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "skin edge does not have exactly two adjacent triangles");
  }
 
  int num_nodes = 0;
  const EntityHandle *conn = nullptr;
  CHKERR mField.get_moab().get_connectivity(edge, conn, num_nodes, false);
  if (num_nodes < 2) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "edge connectivity has fewer than 2 nodes");
  }
 
  const auto base = entPtr->getApproxBase();
  double edge_shape_function_val = 0.0;
  switch (base) {
  case AINSWORTH_LEGENDRE_BASE:
    edge_shape_function_val = 0.25;
    break;
  case AINSWORTH_LOBATTO_BASE:
    edge_shape_function_val = 0.25 * LOBATTO_PHI0(0);
    break;
  case DEMKOWICZ_JACOBI_BASE: {
    double L[3];
    CHKERR Legendre_polynomials(2, 0, NULL, L, NULL, 1);
    edge_shape_function_val = 0.125 * LOBATTO_PHI0(0);
  } break;
  default:
    SETERRQ(PETSC_COMM_SELF, MOFEM_NOT_IMPLEMENTED, "not yet implemented");
  }
 
  auto ent_data = entPtr->getEntFieldData();
  auto t_ent_data = getFTensor1FromPtr<3>(&ent_data(0));
  if (ent_data.size() != 3) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "edge data size mismatch");
  }
  coords.resize(num_nodes * 3);
  CHKERR mField.get_moab().get_coords(conn, num_nodes, &*coords.data().begin());
  FTensor::Tensor1<double, 3> edge_vec;
  FTensor::Tensor1<FTensor::PackPtr<double *, 3>, 3> t_n0(
      &coords[0], &coords[1], &coords[2]);
  FTensor::Tensor1<FTensor::PackPtr<double *, 3>, 3> t_n1(
      &coords[3], &coords[4], &coords[5]);
  edge_vec(i) = t_n1(i) - t_n0(i);
  const double h = edge_vec.l2();
  if (h <= 0.0) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY, "zero-length edge");
  }
  aveMidCoord.resize(3);
  midNodeCoord.resize(3);
  auto t_ave_mid_coord = getFTensor1FromPtr<3>(&aveMidCoord(0));
  auto t_mid_node_coord = getFTensor1FromPtr<3>(&midNodeCoord(0));
  t_ave_mid_coord(i) = 0.5 * (t_n0(i) + t_n1(i));
  t_mid_node_coord(i) =
      t_ave_mid_coord(i) + edge_shape_function_val * t_ent_data(i);
 
  auto tri_normal = [&](const EntityHandle tri,
                        FTensor::Tensor1<double, 3> &t_normal) {
    MoFEMFunctionBeginHot;
    CHKERR mField.getInterface<Tools>()->getTriNormal(tri, &t_normal(0));
    t_normal.normalize();
    MoFEMFunctionReturnHot(0);
  };
 
  FTensor::Tensor1<double, 3> n0;
  FTensor::Tensor1<double, 3> n1;
  CHKERR tri_normal(adj_tris[0], n0);
  CHKERR tri_normal(adj_tris[1], n1);
  const double dot = n0(i) * n1(i);
 
  if (std::abs(dot) >= planarAngleCos) {
    MoFEMFunctionReturnHot(0);
  }
 
  double closest_point[3] = {0.0, 0.0, 0.0};
  EntityHandle closest_tri = 0;
  const double query[3] = {midNodeCoord[0], midNodeCoord[1], midNodeCoord[2]};
  CHKERR fineFeatureTree.closest_triangle(fineFeatureRoot, query, closest_point,
                                          closest_tri);
  if (!closest_tri) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "no closest triangle found on fine mesh");
  }
 
  auto get_disp = [&](double _closest_point[3]) {
    FTensor::Tensor1<double, 3> delta;
    for (int ii = 0; ii < 3; ii++)
      delta(ii) = _closest_point[ii] - midNodeCoord[ii];
    return delta.l2();
  };
 
  double disp = get_disp(closest_point);
 
  if (disp > maxDispFactor * h) {
    // std::cout << "Fallback to full fine tree for edge " << edge << std::endl;
    EntityHandle feature_tri = 0;
    CHKERR fineTree.closest_triangle(fineRoot, query, closest_point,
                                     feature_tri);
    if (feature_tri) {
      disp = get_disp(closest_point);
    }
  }
 
  if (disp > maxDispFactor * h) {
    MOFEM_LOG("SELF", Sev::warning) <<
        "The displacement for edge " << edge
        << " is too large: " << disp << " (max allowed (-max_midnode_disp_factor * h) "
        << maxDispFactor * h << "). Using original mid-edge position.";
    
  } else {
    midNodeCoord[0] = closest_point[0];
    midNodeCoord[1] = closest_point[1];
    midNodeCoord[2] = closest_point[2];
  }
 
  diffNodeCoord.resize(3);
  auto t_diff_node_coord = getFTensor1FromPtr<3>(&diffNodeCoord(0));
  t_diff_node_coord(i) = t_mid_node_coord(i) - t_ave_mid_coord(i);
  dOf.resize(3);
  auto t_dof = getFTensor1FromPtr<3>(&dOf(0));
  t_dof(i) = t_diff_node_coord(i) / edge_shape_function_val;
  if (entPtr->getNbOfCoeffs() > 3) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "this method works only fields which are rank 3 or lower");
  }
  ent_data[0] = dOf[0];
  ent_data[1] = dOf[1];
  ent_data[2] = dOf[2];
 
  MoFEMFunctionReturnHot(0);
}

◆ postProcess()

MoFEMErrorCode MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::postProcess ( )

virtual

Post-processing function executed at loop completion.

This virtual function is called once at the end of the loop. It is typically used for:

Assembling matrices and vectors to global system
Computing global variables (e.g., total internal energy)
Finalizing computation results
Cleanup operations

Example of iterating over DOFs:

for(_IT_GET_FEROW_BY_NAME_DOFS_FOR_LOOP_(this,"DISPLACEMENT",it)) { 
  // Process each DOF
}

Returns: Error code indicating success or failure

Reimplemented from MoFEM::BasicMethod.

Definition at line 455 of file Projection10NodeCoordsOnField.cpp.

                                                                         {
  MoFEMFunctionBeginHot;
  MoFEMFunctionReturnHot(0);
}

◆ preProcess()

MoFEMErrorCode MoFEM::Projection10NodeCoordsFromFineSurfaceOnField::preProcess ( )

virtual

Pre-processing function executed at loop initialization.

This virtual function is called once at the beginning of the loop. It is typically used for:

Zeroing matrices and vectors
Computing shape functions on reference elements
Preprocessing boundary conditions
Setting up initial computation state

Returns: Error code indicating success or failure

Reimplemented from MoFEM::BasicMethod.

Definition at line 209 of file Projection10NodeCoordsOnField.cpp.

                                                                        {
  MoFEMFunctionBeginHot;
 
  // Build coarse skin triangles from volume mesh.
  Range coarse_vols;
  CHKERR mField.get_moab().get_entities_by_dimension(0, 3, coarse_vols);
  if (coarse_vols.empty()) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "no 3d entities found in coarse mesh");
  }
 
  Skinner coarse_skinner(&mField.get_moab());
  coarseSkinTris.clear();
  CHKERR coarse_skinner.find_skin(0, coarse_vols, false, coarseSkinTris);
  if (coarseSkinTris.empty()) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "no skin triangles found in coarse mesh");
  }
 
  coarseSkinEdges.clear();
  CHKERR mField.get_moab().get_adjacencies(coarseSkinTris, 1, false,
                                          coarseSkinEdges,
                                          moab::Interface::UNION);
 
  if (fineTris.empty()) {
    SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY,
            "no surface triangles found in fine mesh");
  }
 
  auto tri_normal = [&](const EntityHandle tri,
                        FTensor::Tensor1<double, 3> &normal) {
    MoFEMFunctionBeginHot;
    const EntityHandle *conn;
    int num_nodes;
    double coords[9];
    CHKERR fineMoab.get_connectivity(tri, conn, num_nodes, true);
    CHKERR fineMoab.get_coords(conn, num_nodes, coords);
 
    CHKERR mField.getInterface<Tools>()->getTriNormal(coords, &normal(0));
    normal.normalize();
    MoFEMFunctionReturnHot(0);
  };
 
  const double fine_planar_cos =
      std::cos(std::acos(planarAngleCos) * 1e-6);
 
  Range fine_edges;
  CHKERR fineMoab.get_adjacencies(fineTris, 1, true, fine_edges,
                                  moab::Interface::UNION);
 
  if (debugSurfaces) {
    CHKERR CutMeshInterface::SaveData(fineMoab)("fine_edge_features.vtk",
                                                fine_edges);
  }
  fineFeatureTris.clear();
  for (auto edge : fine_edges) {
    Range adj_tris;
    CHKERR fineMoab.get_adjacencies(&edge, 1, 2, false, adj_tris,
                                    moab::Interface::UNION);
    adj_tris = intersect(adj_tris, fineTris);
    if (adj_tris.size() != 2) {
      continue;
    }
 
    FTensor::Tensor1<double, 3> n0;
    FTensor::Tensor1<double, 3> n1;
    CHKERR tri_normal(adj_tris[0], n0);
    CHKERR tri_normal(adj_tris[1], n1);
    const double dot = n0(i) * n1(i);
    if (std::abs(dot) < fine_planar_cos) {
      fineFeatureTris.insert(adj_tris[0]);
      fineFeatureTris.insert(adj_tris[1]);
    }
  }
 
  filterOuterTrisByEdges(fineMoab, fineFeatureTris);
  if (fineFeatureTris.empty()) {
    fineFeatureTris = fineTris;
  }
  if (debugSurfaces) {
    CHKERR CutMeshInterface::SaveData(fineMoab)("fine_tri_features.vtk",
                                                fineFeatureTris);
  }
 
  // KD tree on fine surface for closest-point queries.
  fineRoot = 0;
  CHKERR fineTree.build_tree(fineTris, &fineRoot);
  fineFeatureRoot = 0;
  CHKERR fineFeatureTree.build_tree(fineFeatureTris, &fineFeatureRoot);
 
  MoFEMFunctionReturnHot(0);
}