localopt.cpp

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#include "localopt.hpp"
#include "optimization.hpp"
#include "physics.hpp"
#include "display.hpp"
#include <map>
using namespace std;

template<Space s>
struct LocalOpt: public NLOpt {
	vector<Node*>& nodes;
    vector<Vec3> x0;
    vector<Constraint*> cons;    
    mutable vector<Vec3> F;
    mutable SpMat<Mat3x3> J;
    const vector<Face*>& faces;
    const vector<Edge*>& edges;    
    LocalOpt (vector<Node*>& nodes, const vector<Face*>& faces, const vector<Edge*>& edges,
              const vector<Constraint*>& pcons);
    void update(const double* x) const;
    void initialize (double *x) const;
    void precompute (const double *x) const;
    void finalize (const double *x) const;    
    double objective (const double *x) const;
    void gradient (const double *x, double *g) const;
    bool hessian (const double *x, SpMat<double> &H) const;
};

template<Space s>
LocalOpt<s>::LocalOpt(vector<Node*>& nodes, const vector<Face*>& faces, const vector<Edge*>& edges, 
                       const vector<Constraint*>& pcons) :
	nodes(nodes), faces(faces), edges(edges)
{
    int nn = nodes.size();
	x0.resize(nn);
    F.resize(nn);
    J = SpMat<Mat3x3>(nn,nn);
    nvar = 3*nn;
    for (size_t i=0; i<nn; i++) {
        x0[i] = pos<s>(nodes[i]);
        nodes[i]->index = i;
    }
    // reduce constraints
    for (size_t n=0; n<pcons.size(); n++) {
        for (size_t i=0; i<nn; i++) {
            if (pcons[n]->contains(nodes[i])) {
                cons.push_back(pcons[n]);
                break;
            }
        }
    }
}

template<Space s>
void LocalOpt<s>::initialize (double *x) const {
    for (int i=0; i<nvar; i++)
        x[i] = 0;
}

template<Space s>
void LocalOpt<s>::update(const double* x) const {
    for (int no=0; no<nodes.size(); no++)
        pos<s>(nodes[no]) = x0[no] + get_subvec(x,no);
}

template<Space s>
void LocalOpt<s>::precompute (const double *x) const {
	update(x);
	for (size_t n = 0; n < nodes.size(); n++) {
        F[n] = Vec3(0);
        for (size_t jj = 0; jj < J.rows[n].entries.size(); jj++)
            J.rows[n].entries[jj] = Mat3x3(0);
    }
    add_internal_forces<s>(faces, edges, J, F, 0);
    add_constraint_forces(cons, J, F, 0);
}

template<Space s>
double LocalOpt<s>::objective (const double *x) const {
    update(x);    
    double E = internal_energy<s>(faces, edges);
    E += constraint_energy(cons);
    if (s == WS) {
        for (size_t n = 0; n < nodes.size(); n++) {
            const Node *node = nodes[n];
            E += node->m * dot(node->acceleration, node->x);
        }
    }
    return E;
}

template<Space s>
void LocalOpt<s>::gradient (const double *x, double *g) const {
    for (int no=0; no<nodes.size(); no++) {
    	Vec3 f = -F[no];
    	if (s == WS)
    		f += nodes[no]->m*nodes[no]->acceleration; // retain acceleration
        set_subvec(g, no, f);
        if (is_bullshit(f)) {
            cout << "bs alert!" << endl;
            Annotation::add(nodes[no]);
            wait_key();
        }
    }
}

template<Space s>
bool LocalOpt<s>::hessian (const double *x, SpMat<double> &H) const {
    double tr = 0; // for regularization
    for (size_t i = 0; i < nodes.size(); i++) {
        const SpVec<Mat3x3> &Ji = J.rows[i];
        for (int jj = 0; jj < Ji.indices.size(); jj++) {
            int j = Ji.indices[jj];
            const Mat3x3 &Jij = Ji.entries[jj];
            set_submat(H, i, j, Jij);
        }
        tr += trace(get_submat(H, i, i));
    }
    Mat3x3 reg = Mat3x3(1e-12*tr/nodes.size()); //regularization
    for (size_t i = 0; i < nodes.size(); i++)
        add_submat(H, i, i, reg);
    // TODO: should add constraint hessian, too
    return true;
}

template<Space s>
void LocalOpt<s>::finalize (const double *x) const {
    update(x);
}

template<Space s>
void local_opt(vector<Node*>& nodes, vector<Face*>& faces, vector<Edge*>& edges,
        const vector<Constraint*>& cons) 
{
	// mark nodes active for physics
    activate_nodes(nodes);
    line_search_newtons_method(LocalOpt<s>(nodes, faces, edges, cons),
                               OptOptions().max_iter(10));
    deactivate_nodes(nodes);
    compute_ws_data(nodes);
    compute_ws_data(faces);
}

template void local_opt<PS>(vector<Node*>& nodes, vector<Face*>& faces,
                            vector<Edge*>& edges,
                            const vector<Constraint*>& cons);
template void local_opt<WS>(vector<Node*>& nodes, vector<Face*>& faces,
                            vector<Edge*>& edges,
                            const vector<Constraint*>& cons);