Form of the elasticity potential and forces. More...

#include <ElasticForm.hpp>

Inheritance diagram for polyfem::solver::ElasticForm:

Collaboration diagram for polyfem::solver::ElasticForm:

Public Member Functions
	ElasticForm (const int n_bases, const std::vector< basis::ElementBases > &bases, const std::vector< basis::ElementBases > &geom_bases, const assembler::Assembler &assembler, const assembler::AssemblyValsCache &ass_vals_cache, const double t, const double dt, const bool is_volume)
	Construct a new Elastic Form object.

std::string	name () const override

bool	is_step_valid (const Eigen::VectorXd &x0, const Eigen::VectorXd &x1) const override
	Determine if a step from solution x0 to solution x1 is allowed.

void	update_quantities (const double t, const Eigen::VectorXd &x) override
	Update time-dependent fields.

void	force_material_derivative (const double t, const Eigen::MatrixXd &x, const Eigen::MatrixXd &x_prev, const Eigen::MatrixXd &adjoint, Eigen::VectorXd &term)
	Compute the derivative of the force wrt lame/damping parameters, then multiply the resulting matrix with adjoint_sol.

void	force_shape_derivative (const double t, const int n_verts, const Eigen::MatrixXd &x, const Eigen::MatrixXd &x_prev, const Eigen::MatrixXd &adjoint, Eigen::VectorXd &term)
	Compute the derivative of the force wrt vertex positions, then multiply the resulting matrix with adjoint_sol.

Public Member Functions inherited from polyfem::solver::Form
virtual	~Form ()

virtual void	init (const Eigen::VectorXd &x)
	Initialize the form.

virtual double	value (const Eigen::VectorXd &x) const
	Compute the value of the form multiplied with the weigth.

Eigen::VectorXd	value_per_element (const Eigen::VectorXd &x) const
	Compute the value of the form multiplied with the weigth.

virtual void	first_derivative (const Eigen::VectorXd &x, Eigen::VectorXd &gradv) const
	Compute the first derivative of the value wrt x multiplied with the weigth.

void	second_derivative (const Eigen::VectorXd &x, StiffnessMatrix &hessian) const
	Compute the second derivative of the value wrt x multiplied with the weigth.

virtual double	max_step_size (const Eigen::VectorXd &x0, const Eigen::VectorXd &x1) const
	Determine the maximum step size allowable between the current and next solution.

virtual void	line_search_begin (const Eigen::VectorXd &x0, const Eigen::VectorXd &x1)
	Initialize variables used during the line search.

virtual void	line_search_end ()
	Clear variables used during the line search.

virtual void	post_step (const polysolve::nonlinear::PostStepData &data)
	Update fields after a step in the optimization.

virtual void	solution_changed (const Eigen::VectorXd &new_x)
	Update cached fields upon a change in the solution.

virtual void	init_lagging (const Eigen::VectorXd &x)
	Initialize lagged fields TODO: more than one step.

virtual void	update_lagging (const Eigen::VectorXd &x, const int iter_num)
	Update lagged fields.

virtual int	max_lagging_iterations () const
	Get the maximum number of lagging iteration allowable.

virtual bool	uses_lagging () const
	Does this form require lagging?

void	set_project_to_psd (bool val)
	Set project to psd.

bool	is_project_to_psd () const
	Get if the form's second derivative is projected to psd.

void	enable ()
	Enable the form.

void	disable ()
	Disable the form.

void	set_enabled (const bool enabled)
	Set if the form is enabled.

bool	enabled () const
	Determine if the form is enabled.

virtual double	weight () const
	Get the form's multiplicative constant weight.

void	set_weight (const double weight)
	Set the form's multiplicative constant weight.

virtual bool	is_step_collision_free (const Eigen::VectorXd &x0, const Eigen::VectorXd &x1) const
	Checks if the step is collision free.

void	set_output_dir (const std::string &output_dir)

Protected Member Functions
virtual double	value_unweighted (const Eigen::VectorXd &x) const override
	Compute the elastic potential value.

Eigen::VectorXd	value_per_element_unweighted (const Eigen::VectorXd &x) const override
	Compute the value of the form multiplied with the weigth.

virtual void	first_derivative_unweighted (const Eigen::VectorXd &x, Eigen::VectorXd &gradv) const override
	Compute the first derivative of the value wrt x.

void	second_derivative_unweighted (const Eigen::VectorXd &x, StiffnessMatrix &hessian) const override
	Compute the second derivative of the value wrt x.

Protected Member Functions inherited from polyfem::solver::Form
std::string	resolve_output_path (const std::string &path) const

Private Member Functions
void	compute_cached_stiffness ()
	Compute the stiffness matrix (cached)

Private Attributes
const int	n_bases_

const std::vector< basis::ElementBases > &	bases_

const std::vector< basis::ElementBases > &	geom_bases_

const assembler::Assembler &	assembler_
	Reference to the assembler.

const assembler::AssemblyValsCache &	ass_vals_cache_

double	t_

const double	dt_

const bool	is_volume_

StiffnessMatrix	cached_stiffness_
	Cached stiffness matrix for linear elasticity.

std::unique_ptr< utils::MatrixCache >	mat_cache_
	Matrix cache (mutable because it is modified in second_derivative_unweighted)

Eigen::VectorXd	x_prev_

Additional Inherited Members
Protected Attributes inherited from polyfem::solver::Form
bool	project_to_psd_ = false
	If true, the form's second derivative is projected to be positive semidefinite.

double	weight_ = 1
	weight of the form (e.g., AL penalty weight or Δt²)

bool	enabled_ = true
	If true, the form is enabled.

std::string	output_dir_

Detailed Description

Form of the elasticity potential and forces.

Definition at line 14 of file ElasticForm.hpp.

Constructor & Destructor Documentation

◆ ElasticForm()

polyfem::solver::ElasticForm::ElasticForm	(	const int	n_bases,
		const std::vector< basis::ElementBases > &	bases,
		const std::vector< basis::ElementBases > &	geom_bases,
		const assembler::Assembler &	assembler,
		const assembler::AssemblyValsCache &	ass_vals_cache,
		const double	t,
		const double	dt,
		const bool	is_volume
	)

Construct a new Elastic Form object.

Parameters

state Reference to the simulation state

Definition at line 34 of file ElasticForm.cpp.

References assembler_, compute_cached_stiffness(), polyfem::assembler::Assembler::is_linear(), and mat_cache_.

Here is the call graph for this function:

Member Function Documentation

◆ compute_cached_stiffness()

void polyfem::solver::ElasticForm::compute_cached_stiffness ( )

private

Compute the stiffness matrix (cached)

Definition at line 116 of file ElasticForm.cpp.

References ass_vals_cache_, polyfem::assembler::Assembler::assemble(), assembler_, bases_, cached_stiffness_, geom_bases_, polyfem::assembler::Assembler::is_linear(), is_volume_, n_bases_, and t_.

Referenced by ElasticForm().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ first_derivative_unweighted()

void polyfem::solver::ElasticForm::first_derivative_unweighted	(	const Eigen::VectorXd &	x,
		Eigen::VectorXd &	gradv
	)		const

overrideprotectedvirtual

Compute the first derivative of the value wrt x.

Parameters

[in]	x	Current solution
[out]	gradv	Output gradient of the value wrt x

Implements polyfem::solver::Form.

Definition at line 71 of file ElasticForm.cpp.

References ass_vals_cache_, polyfem::assembler::Assembler::assemble_gradient(), assembler_, bases_, dt_, geom_bases_, is_volume_, n_bases_, t_, x, and x_prev_.

Here is the call graph for this function:

◆ force_material_derivative()

void polyfem::solver::ElasticForm::force_material_derivative	(	const double	t,
		const Eigen::MatrixXd &	x,
		const Eigen::MatrixXd &	x_prev,
		const Eigen::MatrixXd &	adjoint,
		Eigen::VectorXd &	term
	)

Compute the derivative of the force wrt lame/damping parameters, then multiply the resulting matrix with adjoint_sol.

Parameters

	t	Current time
[in]	x	Current solution
[in]	adjoint	Current adjoint solution
[out]	term	Derivative of force multiplied by the adjoint

Definition at line 125 of file ElasticForm.cpp.

References ass_vals_cache_, assembler_, bases_, polyfem::assembler::AssemblyValsCache::compute(), polyfem::assembler::Assembler::compute_dstress_dmu_dlambda(), polyfem::assembler::ViscousDamping::compute_dstress_dpsi_dphi(), polyfem::utils::create_thread_storage(), polyfem::assembler::ElementAssemblyValues::det, dt_, geom_bases_, polyfem::utils::get_local_thread_storage(), polyfem::io::Evaluator::interpolate_at_local_vals(), is_volume_, polyfem::utils::maybe_parallel_for(), polyfem::assembler::Assembler::name(), polyfem::quadrature::Quadrature::points, polyfem::assembler::ElementAssemblyValues::quadrature, quadrature, polyfem::assembler::ElementAssemblyValues::val, vals, polyfem::utils::vector2matrix(), polyfem::quadrature::Quadrature::weights, and x.

Here is the call graph for this function:

◆ force_shape_derivative()

void polyfem::solver::ElasticForm::force_shape_derivative	(	const double	t,
		const int	n_verts,
		const Eigen::MatrixXd &	x,
		const Eigen::MatrixXd &	x_prev,
		const Eigen::MatrixXd &	adjoint,
		Eigen::VectorXd &	term
	)

Compute the derivative of the force wrt vertex positions, then multiply the resulting matrix with adjoint_sol.

Parameters

	t	Current time
[in]	n_verts	Number of vertices
[in]	x	Current solution
[in]	adjoint	Current adjoint solution
[out]	term	Derivative of force multiplied by the adjoint