SolveData.cpp

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#include "SolveData.hpp"
 
#include <polyfem/solver/NLProblem.hpp>
#include <polyfem/solver/forms/Form.hpp>
#include <polyfem/solver/forms/lagrangian/BCLagrangianForm.hpp>
#include <polyfem/solver/forms/lagrangian/MacroStrainLagrangianForm.hpp>
#include <polyfem/solver/forms/BodyForm.hpp>
#include <polyfem/solver/forms/PressureForm.hpp>
#include <polyfem/solver/forms/PeriodicContactForm.hpp>
#include <polyfem/solver/forms/ElasticForm.hpp>
#include <polyfem/solver/forms/FrictionForm.hpp>
#include <polyfem/solver/forms/InertiaForm.hpp>
#include <polyfem/solver/forms/LaggedRegForm.hpp>
#include <polyfem/solver/forms/RayleighDampingForm.hpp>
#include <polyfem/time_integrator/ImplicitTimeIntegrator.hpp>
#include <polyfem/assembler/ViscousDamping.hpp>
#include <polyfem/assembler/PressureAssembler.hpp>
#include <polyfem/assembler/Mass.hpp>
#include <polyfem/assembler/MacroStrain.hpp>
#include <polyfem/utils/Logger.hpp>
#include <polyfem/assembler/PeriodicBoundary.hpp>
 
namespace polyfem::solver
{
    using namespace polyfem::time_integrator;
 
    std::vector<std::shared_ptr<Form>> SolveData::init_forms(
        // General
        const Units &units,
        const int dim,
        const double t,
 
        // Elastic form
        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 assembler::AssemblyValsCache &mass_ass_vals_cache,
 
        // Body form
        const int n_pressure_bases,
        const std::vector<int> &boundary_nodes,
        const std::vector<mesh::LocalBoundary> &local_boundary,
        const std::vector<mesh::LocalBoundary> &local_neumann_boundary,
        const int n_boundary_samples,
        const Eigen::MatrixXd &rhs,
        const Eigen::MatrixXd &sol,
        const assembler::Density &density,
 
        // Pressure form
        const std::vector<mesh::LocalBoundary> &local_pressure_boundary,
        const std::unordered_map<int, std::vector<mesh::LocalBoundary>> &local_pressure_cavity,
        const std::shared_ptr<assembler::PressureAssembler> pressure_assembler,
 
        // Inertia form
        const bool ignore_inertia,
        const StiffnessMatrix &mass,
        const std::shared_ptr<assembler::ViscousDamping> damping_assembler,
 
        // Lagged regularization form
        const double lagged_regularization_weight,
        const int lagged_regularization_iterations,
 
        // Augemented lagrangian form
        // const std::vector<int> &boundary_nodes,
        // const std::vector<mesh::LocalBoundary> &local_boundary,
        // const std::vector<mesh::LocalBoundary> &local_neumann_boundary,
        // const int n_boundary_samples,
        // const StiffnessMatrix &mass,
        const size_t obstacle_ndof,
 
        // Contact form
        const bool contact_enabled,
        const ipc::CollisionMesh &collision_mesh,
        const double dhat,
        const double avg_mass,
        const bool use_convergent_contact_formulation,
        const json &barrier_stiffness,
        const ipc::BroadPhaseMethod broad_phase,
        const double ccd_tolerance,
        const long ccd_max_iterations,
        const bool enable_shape_derivatives,
 
        // Homogenization
        const assembler::MacroStrainValue &macro_strain_constraint,
 
        // Periodic contact
        const bool periodic_contact,
        const Eigen::VectorXi &tiled_to_single,
        const std::shared_ptr<utils::PeriodicBoundary> &periodic_bc,
 
        // Friction form
        const double friction_coefficient,
        const double epsv,
        const int friction_iterations,
 
        // Rayleigh damping form
        const json &rayleigh_damping)
    {
        const bool is_time_dependent = time_integrator != nullptr;
        assert(!is_time_dependent || time_integrator != nullptr);
        const double dt = is_time_dependent ? time_integrator->dt() : 0.0;
        const int ndof = n_bases * dim;
        // if (is_formulation_mixed) // mixed not supported
        //  ndof_ += n_pressure_bases; // pressure is a scalar
        const bool is_volume = dim == 3;
 
        std::vector<std::shared_ptr<Form>> forms;
        al_form.clear();
 
        elastic_form = std::make_shared<ElasticForm>(
            n_bases, bases, geom_bases, assembler, ass_vals_cache,
            t, dt, is_volume);
        forms.push_back(elastic_form);
 
        if (rhs_assembler != nullptr)
        {
            body_form = std::make_shared<BodyForm>(
                ndof, n_pressure_bases, boundary_nodes, local_boundary,
                local_neumann_boundary, n_boundary_samples, rhs, *rhs_assembler,
                density, /*is_formulation_mixed=*/false,
                is_time_dependent);
            body_form->update_quantities(t, sol);
            forms.push_back(body_form);
        }
 
        if (pressure_assembler != nullptr)
        {
            pressure_form = std::make_shared<PressureForm>(
                ndof,
                local_pressure_boundary,
                local_pressure_cavity,
                boundary_nodes,
                n_boundary_samples, *pressure_assembler,
                is_time_dependent);
            pressure_form->update_quantities(t, sol);
            forms.push_back(pressure_form);
        }
 
        inertia_form = nullptr;
        damping_form = nullptr;
        if (is_time_dependent)
        {
            if (!ignore_inertia)
            {
                assert(time_integrator != nullptr);
                inertia_form = std::make_shared<InertiaForm>(mass, *time_integrator);
                forms.push_back(inertia_form);
            }
 
            if (damping_assembler != nullptr)
            {
                damping_form = std::make_shared<ElasticForm>(
                    n_bases, bases, geom_bases, *damping_assembler, ass_vals_cache, t, dt, is_volume);
                forms.push_back(damping_form);
            }
        }
        else
        {
            if (lagged_regularization_weight > 0)
            {
                forms.push_back(std::make_shared<LaggedRegForm>(lagged_regularization_iterations));
                forms.back()->set_weight(lagged_regularization_weight);
            }
        }
 
        if (rhs_assembler != nullptr)
        {
            // assembler::Mass mass_mat_assembler;
            // mass_mat_assembler.set_size(dim);
            StiffnessMatrix mass_tmp = mass;
            // mass_mat_assembler.assemble(dim == 3, n_bases, bases, geom_bases, mass_ass_vals_cache, mass_tmp, true);
            // assert(mass_tmp.rows() == mass.rows() && mass_tmp.cols() == mass.cols());
 
            al_form.push_back(std::make_shared<BCLagrangianForm>(
                ndof, boundary_nodes, local_boundary, local_neumann_boundary,
                n_boundary_samples, mass_tmp, *rhs_assembler, obstacle_ndof, is_time_dependent, t, periodic_bc));
            forms.push_back(al_form.back());
        }
 
        if (macro_strain_constraint.is_active())
        {
            // don't push these two into forms because they take a different input x
            strain_al_lagr_form = std::make_shared<MacroStrainLagrangianForm>(macro_strain_constraint);
        }
 
        contact_form = nullptr;
        periodic_contact_form = nullptr;
        friction_form = nullptr;
        if (contact_enabled)
        {
            const bool use_adaptive_barrier_stiffness = !barrier_stiffness.is_number();
 
            if (periodic_contact)
            {
                periodic_contact_form = std::make_shared<PeriodicContactForm>(
                    collision_mesh, tiled_to_single, dhat, avg_mass, use_convergent_contact_formulation,
                    use_adaptive_barrier_stiffness, is_time_dependent, enable_shape_derivatives, broad_phase, ccd_tolerance,
                    ccd_max_iterations);
 
                if (use_adaptive_barrier_stiffness)
                {
                    periodic_contact_form->set_barrier_stiffness(1);
                    // logger().debug("Using adaptive barrier stiffness");
                }
                else
                {
                    assert(barrier_stiffness.is_number());
                    assert(barrier_stiffness.get<double>() > 0);
                    periodic_contact_form->set_barrier_stiffness(barrier_stiffness);
                    // logger().debug("Using fixed barrier stiffness of {}", contact_form->barrier_stiffness());
                }
            }
            else
            {
                contact_form = std::make_shared<ContactForm>(
                    collision_mesh, dhat, avg_mass, use_convergent_contact_formulation,
                    use_adaptive_barrier_stiffness, is_time_dependent, enable_shape_derivatives, broad_phase, ccd_tolerance * units.characteristic_length(),
                    ccd_max_iterations);
 
                if (use_adaptive_barrier_stiffness)
                {
                    contact_form->set_barrier_stiffness(1);
                    // logger().debug("Using adaptive barrier stiffness");
                }
                else
                {
                    assert(barrier_stiffness.is_number());
                    assert(barrier_stiffness.get<double>() > 0);
                    contact_form->set_barrier_stiffness(barrier_stiffness);
                    // logger().debug("Using fixed barrier stiffness of {}", contact_form->barrier_stiffness());
                }
 
                if (contact_form)
                    forms.push_back(contact_form);
 
                // ----------------------------------------------------------------
            }
 
            if (friction_coefficient != 0)
            {
                friction_form = std::make_shared<FrictionForm>(
                    collision_mesh, time_integrator, epsv, friction_coefficient,
                    broad_phase, *contact_form, friction_iterations);
                friction_form->init_lagging(sol);
                forms.push_back(friction_form);
            }
        }
 
        const std::vector<json> rayleigh_damping_jsons = utils::json_as_array(rayleigh_damping);
        if (is_time_dependent)
        {
            // Map from form name to form so RayleighDampingForm::create can get the correct form to damp
            const std::unordered_map<std::string, std::shared_ptr<Form>> possible_forms_to_damp = {
                {"elasticity", elastic_form},
                {"contact", contact_form},
            };
 
            for (const json &params : rayleigh_damping_jsons)
            {
                forms.push_back(RayleighDampingForm::create(
                    params, possible_forms_to_damp,
                    *time_integrator));
            }
        }
        else if (rayleigh_damping_jsons.size() > 0)
        {
            log_and_throw_adjoint_error("Rayleigh damping is only supported for time-dependent problems");
        }
 
        update_dt();
 
        return forms;
    }
 
    void SolveData::update_barrier_stiffness(const Eigen::VectorXd &x)
    {
        if (contact_form == nullptr || !contact_form->use_adaptive_barrier_stiffness())
            return;
 
        Eigen::VectorXd grad_energy = Eigen::VectorXd::Zero(x.size());
        const std::array<std::shared_ptr<Form>, 4> energy_forms{
            {elastic_form, inertia_form, body_form, pressure_form}};
        for (const std::shared_ptr<Form> &form : energy_forms)
        {
            if (form == nullptr || !form->enabled())
                continue;
 
            Eigen::VectorXd grad_form;
            form->first_derivative(x, grad_form);
            grad_energy += grad_form;
        }
 
        contact_form->update_barrier_stiffness(x, grad_energy);
    }
 
    void SolveData::update_dt()
    {
        if (time_integrator == nullptr) // if is not time dependent
            return;
 
        const std::array<std::shared_ptr<Form>, 6> energy_forms{
            {elastic_form, body_form, pressure_form, damping_form, contact_form, friction_form}};
        for (const std::shared_ptr<Form> &form : energy_forms)
        {
            if (form == nullptr)
                continue;
            form->set_weight(time_integrator->acceleration_scaling());
        }
    }
 
    std::vector<std::pair<std::string, std::shared_ptr<solver::Form>>> SolveData::named_forms() const
    {
        std::vector<std::pair<std::string, std::shared_ptr<solver::Form>>> res{
            {"elastic", elastic_form},
            {"inertia", inertia_form},
            {"body", body_form},
            {"contact", contact_form},
            {"friction", friction_form},
            {"damping", damping_form},
            {"pressure", pressure_form},
            {"strain_augmented_lagrangian_lagr", strain_al_lagr_form},
            {"periodic_contact", periodic_contact_form},
        };
 
        for (const auto &form : al_form)
            res.push_back({"augmented_lagrangian", form});
 
        return res;
    }
} // namespace polyfem::solver