Reimplemented Goal springs for the Eigen CG solver method.
Note that goal springs currently are really bad ... They have a factor on hairs that "fades" goal influence from the root to the tip. The last point on the hair is completely free, which makes the goal springs pretty much useless on their own without supporting bend stiffness. Can only assume this was added to compensate unphysical behavior of goal springs when using uniform weight, but it's a poor replacement for true localized bending forces ...
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d2c0503f19
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722fd30a9f
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@ -104,19 +104,48 @@ typedef Eigen::ConjugateGradient<lMatrix, Eigen::Lower, Eigen::DiagonalPrecondit
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using Eigen::ComputationInfo;
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static void print_lvector(const lVector &v)
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{
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for (int i = 0; i < v.rows(); ++i) {
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printf("%f,\n", v[i]);
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}
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}
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static void print_lmatrix(const lMatrix &m)
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{
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for (int j = 0; j < m.rows(); ++j) {
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for (int i = 0; i < m.cols(); ++i) {
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printf("%-16f,", m.coeff(j, i));
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}
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printf("\n");
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}
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}
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BLI_INLINE void reserve_diagonal(lMatrix &m, int num)
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{
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m.reserve(Eigen::VectorXi::Constant(m.cols(), num));
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}
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BLI_INLINE float *lVector_v3(lVector &v, int index)
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BLI_INLINE float *lVector_v3(lVector &v, int vertex)
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{
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return v.data() + 3 * index;
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return v.data() + 3 * vertex;
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}
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BLI_INLINE const float *lVector_v3(const lVector &v, int index)
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BLI_INLINE const float *lVector_v3(const lVector &v, int vertex)
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{
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return v.data() + 3 * index;
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return v.data() + 3 * vertex;
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}
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BLI_INLINE void triplets_m3(TripletList &t, float m[3][3], int i, int j)
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{
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i *= 3;
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j *= 3;
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for (int k = 0; k < 3; ++k) {
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for (int l = 0; l < 3; ++l) {
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t.push_back(Triplet(i + k, j + l, m[k][l]));
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}
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}
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}
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struct Implicit_Data {
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@ -185,6 +214,170 @@ static bool simulate_implicit_euler(Implicit_Data *id, float dt)
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return cg.info() != Eigen::Success;
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}
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static void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s, const lVector &X, const lVector &V, float time)
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{
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Cloth *cloth = clmd->clothObject;
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ClothVertex *verts = cloth->verts;
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float extent[3];
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float length = 0, dot = 0;
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float dir[3] = {0, 0, 0};
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float vel[3];
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float k = 0.0f;
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float L = s->restlen;
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float cb; /* = clmd->sim_parms->structural; */ /*UNUSED*/
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float stretch_force[3] = {0, 0, 0};
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float bending_force[3] = {0, 0, 0};
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float damping_force[3] = {0, 0, 0};
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float nulldfdx[3][3] = {{0, 0, 0}, {0, 0, 0}, {0, 0, 0}};
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float scaling = 0.0;
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int no_compress = clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_NO_SPRING_COMPRESS;
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zero_v3(s->f);
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zero_m3(s->dfdx);
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zero_m3(s->dfdv);
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// calculate elonglation
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sub_v3_v3v3(extent, lVector_v3(X, s->kl), lVector_v3(X, s->ij));
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sub_v3_v3v3(vel, lVector_v3(V, s->kl), lVector_v3(V, s->ij));
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dot = dot_v3v3(extent, extent);
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length = sqrt(dot);
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s->flags &= ~CLOTH_SPRING_FLAG_NEEDED;
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if (length > ALMOST_ZERO) {
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/*
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if (length>L) {
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if ((clmd->sim_parms->flags & CSIMSETT_FLAG_TEARING_ENABLED) &&
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( ((length-L)*100.0f/L) > clmd->sim_parms->maxspringlen )) {
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// cut spring!
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s->flags |= CSPRING_FLAG_DEACTIVATE;
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return;
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}
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}
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*/
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mul_v3_v3fl(dir, extent, 1.0f/length);
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}
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else {
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zero_v3(dir);
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}
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#if 0
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// calculate force of structural + shear springs
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if ((s->type & CLOTH_SPRING_TYPE_STRUCTURAL) || (s->type & CLOTH_SPRING_TYPE_SHEAR) || (s->type & CLOTH_SPRING_TYPE_SEWING) ) {
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if (length > L || no_compress) {
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s->flags |= CLOTH_SPRING_FLAG_NEEDED;
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k = clmd->sim_parms->structural;
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scaling = k + s->stiffness * fabsf(clmd->sim_parms->max_struct - k);
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k = scaling / (clmd->sim_parms->avg_spring_len + FLT_EPSILON);
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// TODO: verify, half verified (couldn't see error)
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if (s->type & CLOTH_SPRING_TYPE_SEWING) {
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// sewing springs usually have a large distance at first so clamp the force so we don't get tunnelling through colission objects
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float force = k*(length-L);
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if (force > clmd->sim_parms->max_sewing) {
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force = clmd->sim_parms->max_sewing;
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}
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mul_fvector_S(stretch_force, dir, force);
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}
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else {
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mul_fvector_S(stretch_force, dir, k * (length - L));
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}
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VECADD(s->f, s->f, stretch_force);
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// Ascher & Boxman, p.21: Damping only during elonglation
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// something wrong with it...
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mul_fvector_S(damping_force, dir, clmd->sim_parms->Cdis * dot_v3v3(vel, dir));
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VECADD(s->f, s->f, damping_force);
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/* VERIFIED */
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dfdx_spring(s->dfdx, dir, length, L, k);
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/* VERIFIED */
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dfdv_damp(s->dfdv, dir, clmd->sim_parms->Cdis);
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}
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}
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else
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#endif
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if (s->type & CLOTH_SPRING_TYPE_GOAL) {
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float target[3];
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s->flags |= CLOTH_SPRING_FLAG_NEEDED;
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// current_position = xold + t * (xnew - xold)
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interp_v3_v3v3(target, verts[s->ij].xold, verts[s->ij].xconst, time);
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sub_v3_v3v3(extent, lVector_v3(X, s->ij), target);
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BKE_sim_debug_data_add_line(clmd->debug_data, verts[s->ij].xconst, verts[s->ij].xold, 1,0,0, "springs", hash_vertex(7825, s->ij));
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// SEE MSG BELOW (these are UNUSED)
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// dot = dot_v3v3(extent, extent);
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// length = sqrt(dot);
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k = clmd->sim_parms->goalspring;
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scaling = k + s->stiffness * fabsf(clmd->sim_parms->max_struct - k);
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k = verts[s->ij].goal * scaling / (clmd->sim_parms->avg_spring_len + FLT_EPSILON);
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madd_v3_v3fl(s->f, extent, -k);
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/* XXX this has no effect: dir is always null at this point! - lukas_t
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madd_v3_v3fl(s->f, dir, clmd->sim_parms->goalfrict * 0.01f * dot_v3v3(vel, dir));
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*/
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// HERE IS THE PROBLEM!!!!
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// dfdx_spring(s->dfdx, dir, length, 0.0, k);
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// dfdv_damp(s->dfdv, dir, MIN2(1.0, (clmd->sim_parms->goalfrict/100.0)));
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}
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#if 0
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else { /* calculate force of bending springs */
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if (length < L) {
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s->flags |= CLOTH_SPRING_FLAG_NEEDED;
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k = clmd->sim_parms->bending;
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scaling = k + s->stiffness * fabsf(clmd->sim_parms->max_bend - k);
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cb = k = scaling / (20.0f * (clmd->sim_parms->avg_spring_len + FLT_EPSILON));
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mul_fvector_S(bending_force, dir, fbstar(length, L, k, cb));
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VECADD(s->f, s->f, bending_force);
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dfdx_spring_type2(s->dfdx, dir, length, L, k, cb);
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}
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}
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#endif
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}
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static void cloth_apply_spring_force(ClothModifierData *clmd, ClothSpring *s, lVector &F, lMatrix &dFdX, lMatrix &dFdV)
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{
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TripletList trips;
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// lMatrix tmp(F.rows(), F.rows());
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if (s->flags & CLOTH_SPRING_FLAG_NEEDED) {
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// if (!(s->type & CLOTH_SPRING_TYPE_BENDING)) {
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// triplets_m3(trips, s->dfdv, s->ij, s->kl);
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// triplets_m3(trips, s->dfdv, s->kl, s->ij);
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// tmp.setFromTriplets(trips.begin(), trips.end());
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// dFdV -= tmp;
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// }
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add_v3_v3(lVector_v3(F, s->ij), s->f);
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if (!(s->type & CLOTH_SPRING_TYPE_GOAL))
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sub_v3_v3(lVector_v3(F, s->kl), s->f);
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BKE_sim_debug_data_add_vector(clmd->debug_data, clmd->clothObject->verts[s->ij].x, s->f, 1, 1, 1, "hairs", hash_vertex(3924, s->ij));
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// triplets_m3(trips, s->dfdx, s->ij, s->kl);
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// triplets_m3(trips, s->dfdx, s->kl, s->ij);
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// tmp.setFromTriplets(trips.begin(), trips.end());
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// dFdX -= tmp;
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}
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}
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static void cloth_calc_force(ClothModifierData *clmd, lVector &F, lMatrix &dFdX, lMatrix &dFdV, const lVector &X, const lVector &V, const lMatrix &M, ListBase *effectors, float time)
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{
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Cloth *cloth = clmd->clothObject;
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@ -196,10 +389,11 @@ static void cloth_calc_force(ClothModifierData *clmd, lVector &F, lMatrix &dFdX,
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// diagonal.setZero
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TripletList coeff_dFdX, coeff_dFdV;
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/* set dFdX jacobi matrix to zero */
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F.setZero();
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dFdX.setZero();
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/* set dFdV jacobi matrix diagonal entries to -spring_air */
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dFdV.setZero();
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/* set dFdV jacobi matrix diagonal entries to -spring_air */
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// dFdV.setIdentity();
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// initdiag_bfmatrix(dFdV, tm2);
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@ -214,7 +408,7 @@ static void cloth_calc_force(ClothModifierData *clmd, lVector &F, lMatrix &dFdX,
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/* initialize force with gravity */
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for (int i = 0; i < numverts; ++i) {
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/* gravitational mass same as inertial mass */
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mul_v3_v3(lVector_v3(F, i), gravity, verts[i].mass);
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mul_v3_v3fl(lVector_v3(F, i), gravity, verts[i].mass);
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}
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#if 0
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@ -341,29 +535,23 @@ static void cloth_calc_force(ClothModifierData *clmd, lVector &F, lMatrix &dFdX,
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del_lfvector(winvec);
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}
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#endif
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// calculate spring forces
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search = cloth->springs;
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while (search) {
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for (LinkNode *link = cloth->springs; link; link = link->next) {
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// only handle active springs
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ClothSpring *spring = search->link;
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ClothSpring *spring = (ClothSpring *)link->link;
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if (!(spring->flags & CLOTH_SPRING_FLAG_DEACTIVATE))
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cloth_calc_spring_force(clmd, search->link, lF, lX, lV, dFdV, dFdX, time);
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search = search->next;
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cloth_calc_spring_force(clmd, spring, X, V, time);
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}
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// apply spring forces
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search = cloth->springs;
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while (search) {
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for (LinkNode *link = cloth->springs; link; link = link->next) {
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// only handle active springs
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ClothSpring *spring = search->link;
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ClothSpring *spring = (ClothSpring *)link->link;
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if (!(spring->flags & CLOTH_SPRING_FLAG_DEACTIVATE))
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cloth_apply_spring_force(clmd, search->link, lF, lX, lV, dFdV, dFdX);
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search = search->next;
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cloth_apply_spring_force(clmd, spring, F, dFdX, dFdV);
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}
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// printf("\n");
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#endif
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}
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int implicit_solver(Object *ob, float frame, ClothModifierData *clmd, ListBase *effectors)
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@ -380,17 +568,15 @@ int implicit_solver(Object *ob, float frame, ClothModifierData *clmd, ListBase *
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BKE_sim_debug_data_clear_category(clmd->debug_data, "collision");
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#if 0
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if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL) { /* do goal stuff */
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for (i = 0; i < numverts; i++) {
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for (int i = 0; i < numverts; i++) {
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// update velocities with constrained velocities from pinned verts
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if (verts [i].flags & CLOTH_VERT_FLAG_PINNED) {
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sub_v3_v3v3(id->V[i], verts[i].xconst, verts[i].xold);
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if (verts[i].flags & CLOTH_VERT_FLAG_PINNED) {
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sub_v3_v3v3(lVector_v3(id->V, i), verts[i].xconst, verts[i].xold);
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// mul_v3_fl(id->V[i], clmd->sim_parms->stepsPerFrame);
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}
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}
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}
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#endif
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if (clmd->debug_data) {
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for (int i = 0; i < numverts; i++) {
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@ -437,10 +623,11 @@ int implicit_solver(Object *ob, float frame, ClothModifierData *clmd, ListBase *
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copy_v3_v3(verts[i].txold, lVector_v3(id->X, i));
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// if (!(verts[i].flags & CLOTH_VERT_FLAG_PINNED) && i > 0) {
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// BKE_sim_debug_data_add_line(clmd->debug_data, id->X[i], id->X[i-1], 0.6, 0.3, 0.3, "hair", hash_vertex(4892, i));
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// BKE_sim_debug_data_add_line(clmd->debug_data, id->Xnew[i], id->Xnew[i-1], 1, 0.5, 0.5, "hair", hash_vertex(4893, i));
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// }
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if (!(verts[i].flags & CLOTH_VERT_FLAG_PINNED) && i > 0) {
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BKE_sim_debug_data_add_line(clmd->debug_data, lVector_v3(id->X, i), lVector_v3(id->X, i-1), 0.6, 0.3, 0.3, "hair", hash_vertex(4892, i));
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BKE_sim_debug_data_add_line(clmd->debug_data, lVector_v3(id->Xnew, i), lVector_v3(id->Xnew, i-1), 1, 0.5, 0.5, "hair", hash_vertex(4893, i));
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BKE_sim_debug_data_add_line(clmd->debug_data, verts[i].xconst, verts[i-1].xconst, 0.25, 0.4, 0.25, "hair", hash_vertex(4873, i));
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}
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// BKE_sim_debug_data_add_vector(clmd->debug_data, id->X[i], id->V[i], 0, 0, 1, "velocity", hash_vertex(3158, i));
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}
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