diff options
Diffstat (limited to 'source/blender/physics/intern/BPH_mass_spring.cpp')
-rw-r--r-- | source/blender/physics/intern/BPH_mass_spring.cpp | 1093 |
1 files changed, 1093 insertions, 0 deletions
diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp b/source/blender/physics/intern/BPH_mass_spring.cpp index 1387f633c20..830f346cd39 100644 --- a/source/blender/physics/intern/BPH_mass_spring.cpp +++ b/source/blender/physics/intern/BPH_mass_spring.cpp @@ -1,3 +1,4 @@ +<<<<<<< master /*
* ***** BEGIN GPL LICENSE BLOCK *****
*
@@ -1115,3 +1116,1095 @@ bool BPH_cloth_solver_get_texture_data(Object *UNUSED(ob), ClothModifierData *cl return true;
}
+======= +/* + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * The Original Code is Copyright (C) Blender Foundation + * All rights reserved. + * + * The Original Code is: all of this file. + * + * Contributor(s): Lukas Toenne + * + * ***** END GPL LICENSE BLOCK ***** + */ + +/** \file blender/physics/intern/BPH_mass_spring.cpp + * \ingroup bph + */ + +extern "C" { +#include "MEM_guardedalloc.h" + +#include "DNA_cloth_types.h" +#include "DNA_scene_types.h" +#include "DNA_object_force.h" +#include "DNA_object_types.h" +#include "DNA_meshdata_types.h" +#include "DNA_modifier_types.h" + +#include "BLI_math.h" +#include "BLI_linklist.h" +#include "BLI_utildefines.h" + +#include "BKE_cloth.h" +#include "BKE_collision.h" +#include "BKE_effect.h" +} + +#include "BPH_mass_spring.h" +#include "implicit.h" + +static float I3[3][3] = {{1.0, 0.0, 0.0}, {0.0, 1.0, 0.0}, {0.0, 0.0, 1.0}}; + +/* Number of off-diagonal non-zero matrix blocks. + * Basically there is one of these for each vertex-vertex interaction. + */ +static int cloth_count_nondiag_blocks(Cloth *cloth) +{ + LinkNode *link; + int nondiag = 0; + + for (link = cloth->springs; link; link = link->next) { + ClothSpring *spring = (ClothSpring *)link->link; + + switch (spring->type) { + case CLOTH_SPRING_TYPE_BENDING_ANG: + /* angular bending combines 3 vertices */ + nondiag += 3; + break; + + default: + /* all other springs depend on 2 vertices only */ + nondiag += 1; + break; + } + } + + return nondiag; +} + +static struct Implicit_Data *cloth_solver_init_data(Cloth *cloth) +{ + int totvert = cloth->numverts; + + if (cloth->implicit && totvert != BPH_mass_spring_solver_numvert(cloth->implicit)) { + BPH_mass_spring_solver_free(cloth->implicit); + cloth->implicit = NULL; + } + + if (!cloth->implicit) { + int nondiag = cloth_count_nondiag_blocks(cloth); + cloth->implicit = BPH_mass_spring_solver_create(totvert, nondiag); + } + + return cloth->implicit; +} + +int BPH_cloth_solver_init(Object *UNUSED(ob), ClothModifierData *clmd) +{ + Cloth *cloth = clmd->clothObject; + ClothVertex *vert; + const float ZERO[3] = {0.0f, 0.0f, 0.0f}; + Implicit_Data *id = cloth_solver_init_data(cloth); + unsigned int i; + + vert = cloth->verts; + for (i = 0; i < cloth->numverts; ++i, ++vert) { + BPH_mass_spring_set_vertex_mass(id, i, vert->mass); + BPH_mass_spring_set_motion_state(id, i, vert->x, ZERO); + } + + return 1; +} + +void BPH_cloth_solver_free(ClothModifierData *clmd) +{ + Cloth *cloth = clmd->clothObject; + + if (cloth->implicit) { + BPH_mass_spring_solver_free(cloth->implicit); + cloth->implicit = NULL; + } +} + +void BPH_cloth_solver_set_positions(ClothModifierData *clmd) +{ + Cloth *cloth = clmd->clothObject; + ClothVertex *vert; + unsigned int numverts = cloth->numverts, i; + ClothHairData *cloth_hairdata = clmd->hairdata; + Implicit_Data *id = cloth_solver_init_data(cloth); + + vert = cloth->verts; + for (i = 0; i < numverts; ++i, ++vert) { + if (cloth_hairdata) { + ClothHairData *root = &cloth_hairdata[i]; + BPH_mass_spring_set_rest_transform(id, i, root->rot); + } + else + BPH_mass_spring_set_rest_transform(id, i, I3); + + BPH_mass_spring_set_motion_state(id, i, vert->x, vert->v); + } +} + +static bool collision_response(ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, float dt, float restitution, float r_impulse[3]) +{ + Cloth *cloth = clmd->clothObject; + int index = collpair->ap1; + bool result = false; + + float v1[3], v2_old[3], v2_new[3], v_rel_old[3], v_rel_new[3]; + float epsilon2 = BLI_bvhtree_getepsilon(collmd->bvhtree); + + float margin_distance = collpair->distance - epsilon2; + float mag_v_rel; + + zero_v3(r_impulse); + + if (margin_distance > 0.0f) + return false; /* XXX tested before already? */ + + /* only handle static collisions here */ + if ( collpair->flag & COLLISION_IN_FUTURE ) + return false; + + /* velocity */ + copy_v3_v3(v1, cloth->verts[index].v); + collision_get_collider_velocity(v2_old, v2_new, collmd, collpair); + /* relative velocity = velocity of the cloth point relative to the collider */ + sub_v3_v3v3(v_rel_old, v1, v2_old); + sub_v3_v3v3(v_rel_new, v1, v2_new); + /* normal component of the relative velocity */ + mag_v_rel = dot_v3v3(v_rel_old, collpair->normal); + + /* only valid when moving toward the collider */ + if (mag_v_rel < -ALMOST_ZERO) { + float v_nor_old, v_nor_new; + float v_tan_old[3], v_tan_new[3]; + float bounce, repulse; + + /* Collision response based on + * "Simulating Complex Hair with Robust Collision Handling" (Choe, Choi, Ko, ACM SIGGRAPH 2005) + * http://graphics.snu.ac.kr/publications/2005-choe-HairSim/Choe_2005_SCA.pdf + */ + + v_nor_old = mag_v_rel; + v_nor_new = dot_v3v3(v_rel_new, collpair->normal); + + madd_v3_v3v3fl(v_tan_old, v_rel_old, collpair->normal, -v_nor_old); + madd_v3_v3v3fl(v_tan_new, v_rel_new, collpair->normal, -v_nor_new); + + bounce = -v_nor_old * restitution; + + repulse = -margin_distance / dt; /* base repulsion velocity in normal direction */ + /* XXX this clamping factor is quite arbitrary ... + * not sure if there is a more scientific approach, but seems to give good results + */ + CLAMP(repulse, 0.0f, 4.0f * bounce); + + if (margin_distance < -epsilon2) { + mul_v3_v3fl(r_impulse, collpair->normal, max_ff(repulse, bounce) - v_nor_new); + } + else { + bounce = 0.0f; + mul_v3_v3fl(r_impulse, collpair->normal, repulse - v_nor_new); + } + + result = true; + } + + return result; +} + +/* Init constraint matrix + * This is part of the modified CG method suggested by Baraff/Witkin in + * "Large Steps in Cloth Simulation" (Siggraph 1998) + */ +static void cloth_setup_constraints(ClothModifierData *clmd, ColliderContacts *contacts, int totcolliders, float dt) +{ + Cloth *cloth = clmd->clothObject; + Implicit_Data *data = cloth->implicit; + ClothVertex *vert; + int numverts = cloth->numverts; + int i, j, v; + + const float ZERO[3] = {0.0f, 0.0f, 0.0f}; + + BPH_mass_spring_clear_constraints(data); + + vert = cloth->verts; + for (v = 0; v < numverts; ++v, ++vert) { + if (vert->flags & CLOTH_VERT_FLAG_PINNED) { + /* pinned vertex constraints */ + BPH_mass_spring_add_constraint_ndof0(data, v, ZERO); /* velocity is defined externally */ + } + + vert->impulse_count = 0; + } + + for (i = 0; i < totcolliders; ++i) { + ColliderContacts *ct = &contacts[i]; + for (j = 0; j < ct->totcollisions; ++j) { + CollPair *collpair = &ct->collisions[j]; + int v = collpair->face1; + float impulse[3]; + +// float restitution = (1.0f - clmd->coll_parms->damping) * (1.0f - ct->ob->pd->pdef_sbdamp); + float restitution = 0.0f; + + vert = &cloth->verts[v]; + /* pinned verts handled separately */ + if (vert->flags & CLOTH_VERT_FLAG_PINNED) + continue; + + /* XXX cheap way of avoiding instability from multiple collisions in the same step + * this should eventually be supported ... + */ + if (vert->impulse_count > 0) + continue; + + /* calculate collision response */ + if (!collision_response(clmd, ct->collmd, collpair, dt, restitution, impulse)) + continue; + + BPH_mass_spring_add_constraint_ndof2(data, i, collpair->normal, impulse); + ++vert->impulse_count; + } + } +} + +/* computes where the cloth would be if it were subject to perfectly stiff edges + * (edge distance constraints) in a lagrangian solver. then add forces to help + * guide the implicit solver to that state. this function is called after + * collisions*/ +static int UNUSED_FUNCTION(cloth_calc_helper_forces)(Object *UNUSED(ob), ClothModifierData *clmd, float (*initial_cos)[3], float UNUSED(step), float dt) +{ + Cloth *cloth= clmd->clothObject; + float (*cos)[3] = (float (*)[3])MEM_callocN(sizeof(float)*3*cloth->numverts, "cos cloth_calc_helper_forces"); + float *masses = (float *)MEM_callocN(sizeof(float)*cloth->numverts, "cos cloth_calc_helper_forces"); + LinkNode *node; + ClothSpring *spring; + ClothVertex *vert; + int i, steps; + + vert = cloth->verts; + for (i=0; i<cloth->numverts; i++, vert++) { + copy_v3_v3(cos[i], vert->tx); + + if (vert->goal == 1.0f || len_squared_v3v3(initial_cos[i], vert->tx) != 0.0f) { + masses[i] = 1e+10; + } + else { + masses[i] = vert->mass; + } + } + + steps = 55; + for (i=0; i<steps; i++) { + for (node=cloth->springs; node; node=node->next) { + /* ClothVertex *cv1, *cv2; */ /* UNUSED */ + int v1, v2; + float len, c, l, vec[3]; + + spring = (ClothSpring *)node->link; + if (spring->type != CLOTH_SPRING_TYPE_STRUCTURAL && spring->type != CLOTH_SPRING_TYPE_SHEAR) + continue; + + v1 = spring->ij; v2 = spring->kl; + /* cv1 = cloth->verts + v1; */ /* UNUSED */ + /* cv2 = cloth->verts + v2; */ /* UNUSED */ + len = len_v3v3(cos[v1], cos[v2]); + + sub_v3_v3v3(vec, cos[v1], cos[v2]); + normalize_v3(vec); + + c = (len - spring->restlen); + if (c == 0.0f) + continue; + + l = c / ((1.0f / masses[v1]) + (1.0f / masses[v2])); + + mul_v3_fl(vec, -(1.0f / masses[v1]) * l); + add_v3_v3(cos[v1], vec); + + sub_v3_v3v3(vec, cos[v2], cos[v1]); + normalize_v3(vec); + + mul_v3_fl(vec, -(1.0f / masses[v2]) * l); + add_v3_v3(cos[v2], vec); + } + } + + vert = cloth->verts; + for (i=0; i<cloth->numverts; i++, vert++) { + float vec[3]; + + /*compute forces*/ + sub_v3_v3v3(vec, cos[i], vert->tx); + mul_v3_fl(vec, vert->mass*dt*20.0f); + add_v3_v3(vert->tv, vec); + //copy_v3_v3(cv->tx, cos[i]); + } + + MEM_freeN(cos); + MEM_freeN(masses); + + return 1; +} + +BLI_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s, float time) +{ + Cloth *cloth = clmd->clothObject; + ClothSimSettings *parms = clmd->sim_parms; + Implicit_Data *data = cloth->implicit; + ClothVertex *verts = cloth->verts; + + bool no_compress = parms->flags & CLOTH_SIMSETTINGS_FLAG_NO_SPRING_COMPRESS; + + zero_v3(s->f); + zero_m3(s->dfdx); + zero_m3(s->dfdv); + + s->flags &= ~CLOTH_SPRING_FLAG_NEEDED; + + // calculate force of structural + shear springs + if ((s->type & CLOTH_SPRING_TYPE_STRUCTURAL) || (s->type & CLOTH_SPRING_TYPE_SHEAR) || (s->type & CLOTH_SPRING_TYPE_SEWING) ) { +#ifdef CLOTH_FORCE_SPRING_STRUCTURAL + float k, scaling; + + s->flags |= CLOTH_SPRING_FLAG_NEEDED; + + scaling = parms->structural + s->stiffness * fabsf(parms->max_struct - parms->structural); + k = scaling / (parms->avg_spring_len + FLT_EPSILON); + + if (s->type & CLOTH_SPRING_TYPE_SEWING) { + // TODO: verify, half verified (couldn't see error) + // sewing springs usually have a large distance at first so clamp the force so we don't get tunnelling through colission objects + BPH_mass_spring_force_spring_linear(data, s->ij, s->kl, s->restlen, k, parms->Cdis, no_compress, parms->max_sewing, s->f, s->dfdx, s->dfdv); + } + else { + BPH_mass_spring_force_spring_linear(data, s->ij, s->kl, s->restlen, k, parms->Cdis, no_compress, 0.0f, s->f, s->dfdx, s->dfdv); + } +#endif + } + else if (s->type & CLOTH_SPRING_TYPE_GOAL) { +#ifdef CLOTH_FORCE_SPRING_GOAL + float goal_x[3], goal_v[3]; + float k, scaling; + + s->flags |= CLOTH_SPRING_FLAG_NEEDED; + + // current_position = xold + t * (newposition - xold) + interp_v3_v3v3(goal_x, verts[s->ij].xold, verts[s->ij].xconst, time); + sub_v3_v3v3(goal_v, verts[s->ij].xconst, verts[s->ij].xold); // distance covered over dt==1 + + scaling = parms->goalspring + s->stiffness * fabsf(parms->max_struct - parms->goalspring); + k = verts[s->ij].goal * scaling / (parms->avg_spring_len + FLT_EPSILON); + + BPH_mass_spring_force_spring_goal(data, s->ij, goal_x, goal_v, k, parms->goalfrict * 0.01f, s->f, s->dfdx, s->dfdv); +#endif + } + else if (s->type & CLOTH_SPRING_TYPE_BENDING) { /* calculate force of bending springs */ +#ifdef CLOTH_FORCE_SPRING_BEND + float kb, cb, scaling; + + s->flags |= CLOTH_SPRING_FLAG_NEEDED; + + scaling = parms->bending + s->stiffness * fabsf(parms->max_bend - parms->bending); + kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON)); + + scaling = parms->bending_damping; + cb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON)); + + BPH_mass_spring_force_spring_bending(data, s->ij, s->kl, s->restlen, kb, cb, s->f, s->dfdx, s->dfdv); +#endif + } + else if (s->type & CLOTH_SPRING_TYPE_BENDING_ANG) { +#ifdef CLOTH_FORCE_SPRING_BEND + float kb, cb, scaling; + + s->flags |= CLOTH_SPRING_FLAG_NEEDED; + + /* XXX WARNING: angular bending springs for hair apply stiffness factor as an overall factor, unlike cloth springs! + * this is crap, but needed due to cloth/hair mixing ... + * max_bend factor is not even used for hair, so ... + */ + scaling = s->stiffness * parms->bending; + kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON)); + + scaling = parms->bending_damping; + cb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON)); + + /* XXX assuming same restlen for ij and jk segments here, this can be done correctly for hair later */ + BPH_mass_spring_force_spring_bending_angular(data, s->ij, s->kl, s->mn, s->target, kb, cb); + +#if 0 + { + float x_kl[3], x_mn[3], v[3], d[3]; + + BPH_mass_spring_get_motion_state(data, s->kl, x_kl, v); + BPH_mass_spring_get_motion_state(data, s->mn, x_mn, v); + + BKE_sim_debug_data_add_dot(clmd->debug_data, x_kl, 0.9, 0.9, 0.9, "target", 7980, s->kl); + BKE_sim_debug_data_add_line(clmd->debug_data, x_kl, x_mn, 0.8, 0.8, 0.8, "target", 7981, s->kl); + + copy_v3_v3(d, s->target); + BKE_sim_debug_data_add_vector(clmd->debug_data, x_kl, d, 0.8, 0.8, 0.2, "target", 7982, s->kl); + +// copy_v3_v3(d, s->target_ij); +// BKE_sim_debug_data_add_vector(clmd->debug_data, x, d, 1, 0.4, 0.4, "target", 7983, s->kl); + } +#endif +#endif + } +} + +static void hair_get_boundbox(ClothModifierData *clmd, float gmin[3], float gmax[3]) +{ + Cloth *cloth = clmd->clothObject; + Implicit_Data *data = cloth->implicit; + unsigned int numverts = cloth->numverts; + ClothVertex *vert; + int i; + + INIT_MINMAX(gmin, gmax); + vert = cloth->verts; + for (i = 0; i < numverts; i++, vert++) { + float x[3]; + BPH_mass_spring_get_motion_state(data, i, x, NULL); + DO_MINMAX(x, gmin, gmax); + } +} + +static void cloth_calc_force(ClothModifierData *clmd, float UNUSED(frame), ListBase *effectors, float time) +{ + /* Collect forces and derivatives: F, dFdX, dFdV */ + Cloth *cloth = clmd->clothObject; + Implicit_Data *data = cloth->implicit; + unsigned int i = 0; + float drag = clmd->sim_parms->Cvi * 0.01f; /* viscosity of air scaled in percent */ + float gravity[3] = {0.0f, 0.0f, 0.0f}; + MFace *mfaces = cloth->mfaces; + unsigned int numverts = cloth->numverts; + ClothVertex *vert; + +#ifdef CLOTH_FORCE_GRAVITY + /* global acceleration (gravitation) */ + if (clmd->scene->physics_settings.flag & PHYS_GLOBAL_GRAVITY) { + /* scale gravity force */ + mul_v3_v3fl(gravity, clmd->scene->physics_settings.gravity, 0.001f * clmd->sim_parms->effector_weights->global_gravity); + } + vert = cloth->verts; + for (i = 0; i < cloth->numverts; i++, vert++) { + BPH_mass_spring_force_gravity(data, i, vert->mass, gravity); + } +#endif + + /* cloth_calc_volume_force(clmd); */ + +#ifdef CLOTH_FORCE_DRAG + BPH_mass_spring_force_drag(data, drag); +#endif + + /* handle external forces like wind */ + if (effectors) { + /* cache per-vertex forces to avoid redundant calculation */ + float (*winvec)[3] = (float (*)[3])MEM_callocN(sizeof(float) * 3 * numverts, "effector forces"); + + vert = cloth->verts; + for (i = 0; i < cloth->numverts; i++, vert++) { + float x[3], v[3]; + EffectedPoint epoint; + + BPH_mass_spring_get_motion_state(data, i, x, v); + pd_point_from_loc(clmd->scene, x, v, i, &epoint); + pdDoEffectors(effectors, NULL, clmd->sim_parms->effector_weights, &epoint, winvec[i], NULL); + } + + for (i = 0; i < cloth->numfaces; i++) { + MFace *mf = &mfaces[i]; + BPH_mass_spring_force_face_wind(data, mf->v1, mf->v2, mf->v3, mf->v4, winvec); + } + + /* Hair has only edges */ + if (cloth->numfaces == 0) { +#if 0 + ClothHairData *hairdata = clmd->hairdata; + ClothHairData *hair_ij, *hair_kl; + + for (LinkNode *link = cloth->springs; link; link = link->next) { + ClothSpring *spring = (ClothSpring *)link->link; + if (spring->type == CLOTH_SPRING_TYPE_STRUCTURAL) { + ClothVertex *verts = cloth->verts; + int si_ij = verts[spring->ij].solver_index; + int si_kl = verts[spring->kl].solver_index; + + if (si_ij < 0 || si_kl < 0) + continue; + + if (hairdata) { + hair_ij = &hairdata[spring->ij]; + hair_kl = &hairdata[spring->kl]; + BPH_mass_spring_force_edge_wind(data, si_ij, si_kl, hair_ij->radius, hair_kl->radius, winvec); + } + else + BPH_mass_spring_force_edge_wind(data, si_ij, si_kl, 1.0f, 1.0f, winvec); + } + } +#else + ClothHairData *hairdata = clmd->hairdata; + + vert = cloth->verts; + for (i = 0; i < cloth->numverts; i++, vert++) { + if (hairdata) { + ClothHairData *hair = &hairdata[i]; + BPH_mass_spring_force_vertex_wind(data, i, hair->radius, winvec); + } + else + BPH_mass_spring_force_vertex_wind(data, i, 1.0f, winvec); + } +#endif + } + + MEM_freeN(winvec); + } + + // calculate spring forces + for (LinkNode *link = cloth->springs; link; link = link->next) { + ClothSpring *spring = (ClothSpring *)link->link; + // only handle active springs + if (!(spring->flags & CLOTH_SPRING_FLAG_DEACTIVATE)) + cloth_calc_spring_force(clmd, spring, time); + } +} + +/* returns vertexes' motion state */ +BLI_INLINE void cloth_get_grid_location(Implicit_Data *data, float cell_scale, const float cell_offset[3], + int index, float x[3], float v[3]) +{ + BPH_mass_spring_get_position(data, index, x); + BPH_mass_spring_get_new_velocity(data, index, v); + + mul_v3_fl(x, cell_scale); + add_v3_v3(x, cell_offset); +} + +/* returns next spring forming a continous hair sequence */ +BLI_INLINE LinkNode *hair_spring_next(LinkNode *spring_link) +{ + ClothSpring *spring = (ClothSpring *)spring_link->link; + LinkNode *next = spring_link->next; + if (next) { + ClothSpring *next_spring = (ClothSpring *)next->link; + if (next_spring->type == CLOTH_SPRING_TYPE_STRUCTURAL && next_spring->kl == spring->ij) + return next; + } + return NULL; +} + +/* XXX this is nasty: cloth meshes do not explicitly store + * the order of hair segments! + * We have to rely on the spring build function for now, + * which adds structural springs in reverse order: + * (3,4), (2,3), (1,2) + * This is currently the only way to figure out hair geometry inside this code ... + */ +static LinkNode *cloth_continuum_add_hair_segments(HairGrid *grid, const float cell_scale, const float cell_offset[3], Cloth *cloth, LinkNode *spring_link) +{ + Implicit_Data *data = cloth->implicit; + LinkNode *next_spring_link = NULL; /* return value */ + ClothSpring *spring1, *spring2, *spring3; + float x1[3], v1[3], x2[3], v2[3], x3[3], v3[3], x4[3], v4[3]; + float dir1[3], dir2[3], dir3[3]; + + spring1 = NULL; + spring2 = NULL; + spring3 = (ClothSpring *)spring_link->link; + + zero_v3(x1); zero_v3(v1); + zero_v3(dir1); + zero_v3(x2); zero_v3(v2); + zero_v3(dir2); + + cloth_get_grid_location(data, cell_scale, cell_offset, spring3->kl, x3, v3); + cloth_get_grid_location(data, cell_scale, cell_offset, spring3->ij, x4, v4); + sub_v3_v3v3(dir3, x4, x3); + normalize_v3(dir3); + + while (spring_link) { + /* move on */ + spring1 = spring2; + spring2 = spring3; + + copy_v3_v3(x1, x2); copy_v3_v3(v1, v2); + copy_v3_v3(x2, x3); copy_v3_v3(v2, v3); + copy_v3_v3(x3, x4); copy_v3_v3(v3, v4); + + copy_v3_v3(dir1, dir2); + copy_v3_v3(dir2, dir3); + + /* read next segment */ + next_spring_link = spring_link->next; + spring_link = hair_spring_next(spring_link); + + if (spring_link) { + spring3 = (ClothSpring *)spring_link->link; + cloth_get_grid_location(data, cell_scale, cell_offset, spring3->ij, x4, v4); + sub_v3_v3v3(dir3, x4, x3); + normalize_v3(dir3); + } + else { + spring3 = NULL; + zero_v3(x4); zero_v3(v4); + zero_v3(dir3); + } + + BPH_hair_volume_add_segment(grid, x1, v1, x2, v2, x3, v3, x4, v4, + spring1 ? dir1 : NULL, + dir2, + spring3 ? dir3 : NULL); + } + + return next_spring_link; +} + +static void cloth_continuum_fill_grid(HairGrid *grid, Cloth *cloth) +{ +#if 0 + Implicit_Data *data = cloth->implicit; + int numverts = cloth->numverts; + ClothVertex *vert; + int i; + + for (i = 0, vert = cloth->verts; i < numverts; i++, vert++) { + float x[3], v[3]; + + cloth_get_vertex_motion_state(data, vert, x, v); + BPH_hair_volume_add_vertex(grid, x, v); + } +#else + LinkNode *link; + float cellsize, gmin[3], cell_scale, cell_offset[3]; + + /* scale and offset for transforming vertex locations into grid space + * (cell size is 0..1, gmin becomes origin) + */ + BPH_hair_volume_grid_geometry(grid, &cellsize, NULL, gmin, NULL); + cell_scale = cellsize > 0.0f ? 1.0f / cellsize : 0.0f; + mul_v3_v3fl(cell_offset, gmin, cell_scale); + negate_v3(cell_offset); + + link = cloth->springs; + while (link) { + ClothSpring *spring = (ClothSpring *)link->link; + if (spring->type == CLOTH_SPRING_TYPE_STRUCTURAL) + link = cloth_continuum_add_hair_segments(grid, cell_scale, cell_offset, cloth, link); + else + link = link->next; + } +#endif + BPH_hair_volume_normalize_vertex_grid(grid); +} + +static void cloth_continuum_step(ClothModifierData *clmd, float dt) +{ + ClothSimSettings *parms = clmd->sim_parms; + Cloth *cloth = clmd->clothObject; + Implicit_Data *data = cloth->implicit; + int numverts = cloth->numverts; + ClothVertex *vert; + + const float fluid_factor = 0.95f; /* blend between PIC and FLIP methods */ + float smoothfac = parms->velocity_smooth; + /* XXX FIXME arbitrary factor!!! this should be based on some intuitive value instead, + * like number of hairs per cell and time decay instead of "strength" + */ + float density_target = parms->density_target; + float density_strength = parms->density_strength; + float gmin[3], gmax[3]; + int i; + + /* clear grid info */ + zero_v3_int(clmd->hair_grid_res); + zero_v3(clmd->hair_grid_min); + zero_v3(clmd->hair_grid_max); + clmd->hair_grid_cellsize = 0.0f; + + hair_get_boundbox(clmd, gmin, gmax); + + /* gather velocities & density */ + if (smoothfac > 0.0f || density_strength > 0.0f) { + HairGrid *grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_cell_size, gmin, gmax); + + cloth_continuum_fill_grid(grid, cloth); + + /* main hair continuum solver */ + BPH_hair_volume_solve_divergence(grid, dt, density_target, density_strength); + + for (i = 0, vert = cloth->verts; i < numverts; i++, vert++) { + float x[3], v[3], nv[3]; + + /* calculate volumetric velocity influence */ + BPH_mass_spring_get_position(data, i, x); + BPH_mass_spring_get_new_velocity(data, i, v); + + BPH_hair_volume_grid_velocity(grid, x, v, fluid_factor, nv); + + interp_v3_v3v3(nv, v, nv, smoothfac); + + /* apply on hair data */ + BPH_mass_spring_set_new_velocity(data, i, nv); + } + + /* store basic grid info in the modifier data */ + BPH_hair_volume_grid_geometry(grid, &clmd->hair_grid_cellsize, clmd->hair_grid_res, clmd->hair_grid_min, clmd->hair_grid_max); + +#if 0 /* DEBUG hair velocity vector field */ + { + const int size = 64; + int i, j; + float offset[3], a[3], b[3]; + const int axis = 0; + const float shift = 0.0f; + + copy_v3_v3(offset, clmd->hair_grid_min); + zero_v3(a); + zero_v3(b); + + offset[axis] = shift * clmd->hair_grid_cellsize; + a[(axis+1) % 3] = clmd->hair_grid_max[(axis+1) % 3] - clmd->hair_grid_min[(axis+1) % 3]; + b[(axis+2) % 3] = clmd->hair_grid_max[(axis+2) % 3] - clmd->hair_grid_min[(axis+2) % 3]; + + BKE_sim_debug_data_clear_category(clmd->debug_data, "grid velocity"); + for (j = 0; j < size; ++j) { + for (i = 0; i < size; ++i) { + float x[3], v[3], gvel[3], gvel_smooth[3], gdensity; + + madd_v3_v3v3fl(x, offset, a, (float)i / (float)(size-1)); + madd_v3_v3fl(x, b, (float)j / (float)(size-1)); + zero_v3(v); + + BPH_hair_volume_grid_interpolate(grid, x, &gdensity, gvel, gvel_smooth, NULL, NULL); + +// BKE_sim_debug_data_add_circle(clmd->debug_data, x, gdensity, 0.7, 0.3, 1, "grid density", i, j, 3111); + if (!is_zero_v3(gvel) || !is_zero_v3(gvel_smooth)) { + float dvel[3]; + sub_v3_v3v3(dvel, gvel_smooth, gvel); +// BKE_sim_debug_data_add_vector(clmd->debug_data, x, gvel, 0.4, 0, 1, "grid velocity", i, j, 3112); +// BKE_sim_debug_data_add_vector(clmd->debug_data, x, gvel_smooth, 0.6, 1, 1, "grid velocity", i, j, 3113); + BKE_sim_debug_data_add_vector(clmd->debug_data, x, dvel, 0.4, 1, 0.7, "grid velocity", i, j, 3114); +#if 0 + if (gdensity > 0.0f) { + float col0[3] = {0.0, 0.0, 0.0}; + float col1[3] = {0.0, 1.0, 0.0}; + float col[3]; + + interp_v3_v3v3(col, col0, col1, CLAMPIS(gdensity * clmd->sim_parms->density_strength, 0.0, 1.0)); +// BKE_sim_debug_data_add_circle(clmd->debug_data, x, gdensity * clmd->sim_parms->density_strength, 0, 1, 0.4, "grid velocity", i, j, 3115); +// BKE_sim_debug_data_add_dot(clmd->debug_data, x, col[0], col[1], col[2], "grid velocity", i, j, 3115); + BKE_sim_debug_data_add_circle(clmd->debug_data, x, 0.01f, col[0], col[1], col[2], "grid velocity", i, j, 3115); + } +#endif + } + } + } + } +#endif + + BPH_hair_volume_free_vertex_grid(grid); + } +} + +/* old collision stuff for cloth, use for continuity + * until a good replacement is ready + */ +static bool cloth_collision_solve_extra(Object *ob, ClothModifierData *clmd, ListBase *effectors, float frame, float step, float dt) +{ + Cloth *cloth = clmd->clothObject; + Implicit_Data *id = cloth->implicit; + ClothVertex *verts = cloth->verts; + int numverts = cloth->numverts; + const float spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;; + + bool do_extra_solve; + int i; + + if (!(clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_ENABLED)) + return false; + if (!clmd->clothObject->bvhtree) + return false; + + // update verts to current positions + for (i = 0; i < numverts; i++) { + BPH_mass_spring_get_new_position(id, i, verts[i].tx); + + sub_v3_v3v3(verts[i].tv, verts[i].tx, verts[i].txold); + copy_v3_v3(verts[i].v, verts[i].tv); + } + +#if 0 /* unused */ + for (i=0, cv=cloth->verts; i<cloth->numverts; i++, cv++) { + copy_v3_v3(initial_cos[i], cv->tx); + } +#endif + + // call collision function + // TODO: check if "step" or "step+dt" is correct - dg + do_extra_solve = cloth_bvh_objcollision(ob, clmd, step/clmd->sim_parms->timescale, dt/clmd->sim_parms->timescale); + + // copy corrected positions back to simulation + for (i = 0; i < numverts; i++) { + float curx[3]; + BPH_mass_spring_get_position(id, i, curx); + // correct velocity again, just to be sure we had to change it due to adaptive collisions + sub_v3_v3v3(verts[i].tv, verts[i].tx, curx); + } + + if (do_extra_solve) { +// cloth_calc_helper_forces(ob, clmd, initial_cos, step/clmd->sim_parms->timescale, dt/clmd->sim_parms->timescale); + + for (i = 0; i < numverts; i++) { + float newv[3]; + + if ((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL) && (verts [i].flags & CLOTH_VERT_FLAG_PINNED)) + continue; + + BPH_mass_spring_set_new_position(id, i, verts[i].tx); + mul_v3_v3fl(newv, verts[i].tv, spf); + BPH_mass_spring_set_new_velocity(id, i, newv); + } + } + + BPH_mass_spring_apply_positions(id); + + if (do_extra_solve) { + ImplicitSolverResult result; + + BPH_mass_spring_apply_velocities(id); + + /* initialize forces to zero */ + BPH_mass_spring_clear_forces(id); + + // calculate forces + cloth_calc_force(clmd, frame, effectors, step); + + // calculate new velocity and position + BPH_mass_spring_solve_velocities(id, dt, &result); +// cloth_record_result(clmd, &result, clmd->sim_parms->stepsPerFrame); + } + + /* note: positions are advanced only once! */ + BPH_mass_spring_apply_velocities(id); + + return true; +} + +static void cloth_clear_result(ClothModifierData *clmd) +{ + ClothSolverResult *sres = clmd->solver_result; + + sres->status = 0; + sres->max_error = sres->min_error = sres->avg_error = 0.0f; + sres->max_iterations = sres->min_iterations = 0; + sres->avg_iterations = 0.0f; +} + +static void cloth_record_result(ClothModifierData *clmd, ImplicitSolverResult *result, int steps) +{ + ClothSolverResult *sres = clmd->solver_result; + + if (sres->status) { /* already initialized ? */ + /* error only makes sense for successful iterations */ + if (result->status == BPH_SOLVER_SUCCESS) { + sres->min_error = min_ff(sres->min_error, result->error); + sres->max_error = max_ff(sres->max_error, result->error); + sres->avg_error += result->error / (float)steps; + } + + sres->min_iterations = min_ii(sres->min_iterations, result->iterations); + sres->max_iterations = max_ii(sres->max_iterations, result->iterations); + sres->avg_iterations += (float)result->iterations / (float)steps; + } + else { + /* error only makes sense for successful iterations */ + if (result->status == BPH_SOLVER_SUCCESS) { + sres->min_error = sres->max_error = result->error; + sres->avg_error += result->error / (float)steps; + } + + sres->min_iterations = sres->max_iterations = result->iterations; + sres->avg_iterations += (float)result->iterations / (float)steps; + } + + sres->status |= result->status; +} + +int BPH_cloth_solve(Object *ob, float frame, ClothModifierData *clmd, ListBase *effectors) +{ + /* Hair currently is a cloth sim in disguise ... + * Collision detection and volumetrics work differently then. + * Bad design, TODO + */ + const bool is_hair = (clmd->hairdata != NULL); + + unsigned int i=0; + float step=0.0f, tf=clmd->sim_parms->timescale; + Cloth *cloth = clmd->clothObject; + ClothVertex *verts = cloth->verts, *vert; + unsigned int numverts = cloth->numverts; + float dt = clmd->sim_parms->timescale / clmd->sim_parms->stepsPerFrame; + Implicit_Data *id = cloth->implicit; + ColliderContacts *contacts = NULL; + int totcolliders = 0; + + BKE_sim_debug_data_clear_category("collision"); + + if (!clmd->solver_result) + clmd->solver_result = (ClothSolverResult *)MEM_callocN(sizeof(ClothSolverResult), "cloth solver result"); + cloth_clear_result(clmd); + + if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL) { /* do goal stuff */ + vert = verts; + for (i = 0; i < numverts; i++, vert++) { + // update velocities with constrained velocities from pinned verts + if (vert->flags & CLOTH_VERT_FLAG_PINNED) { + float v[3]; + + sub_v3_v3v3(v, verts[i].xconst, verts[i].xold); + // mul_v3_fl(v, clmd->sim_parms->stepsPerFrame); + BPH_mass_spring_set_velocity(id, i, v); + } + } + } + + while (step < tf) { + ImplicitSolverResult result; + + /* copy velocities for collision */ + vert = verts; + for (i = 0; i < numverts; i++, vert++) { + BPH_mass_spring_get_motion_state(id, i, NULL, verts[i].tv); + copy_v3_v3(verts[i].v, verts[i].tv); + } + + if (is_hair) { + /* determine contact points */ + if (clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_ENABLED) { + cloth_find_point_contacts(ob, clmd, 0.0f, tf, &contacts, &totcolliders); + } + + /* setup vertex constraints for pinned vertices and contacts */ + cloth_setup_constraints(clmd, contacts, totcolliders, dt); + } + else { + /* setup vertex constraints for pinned vertices */ + cloth_setup_constraints(clmd, NULL, 0, dt); + } + + /* initialize forces to zero */ + BPH_mass_spring_clear_forces(id); + + // damping velocity for artistic reasons + // this is a bad way to do it, should be removed imo - lukas_t + if (clmd->sim_parms->vel_damping != 1.0f) { + vert = verts; + for (i = 0; i < numverts; i++, vert++) { + float v[3]; + BPH_mass_spring_get_motion_state(id, i, NULL, v); + mul_v3_fl(v, clmd->sim_parms->vel_damping); + BPH_mass_spring_set_velocity(id, i, v); + } + } + + // calculate forces + cloth_calc_force(clmd, frame, effectors, step); + + // calculate new velocity and position + BPH_mass_spring_solve_velocities(id, dt, &result); + cloth_record_result(clmd, &result, clmd->sim_parms->stepsPerFrame); + + if (is_hair) { + cloth_continuum_step(clmd, dt); + } + + BPH_mass_spring_solve_positions(id, dt); + + if (!is_hair && cloth_collision_solve_extra(ob, clmd, effectors, frame, step, dt)) { + /* cloth_collision_solve_extra already applies positions */ + } + else { + BPH_mass_spring_apply_positions(id); + } + + BPH_mass_spring_apply_velocities(id); + + /* move pinned verts to correct position */ + vert = verts; + for (i = 0; i < numverts; i++, vert++) { + if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL) { + if (vert->flags & CLOTH_VERT_FLAG_PINNED) { + float x[3]; + interp_v3_v3v3(x, verts[i].xold, verts[i].xconst, step + dt); + BPH_mass_spring_set_position(id, i, x); + } + } + + BPH_mass_spring_get_motion_state(id, i, verts[i].txold, NULL); + } + + /* free contact points */ + if (contacts) { + cloth_free_contacts(contacts, totcolliders); + } + + step += dt; + } + + /* copy results back to cloth data */ + vert = verts; + for (i = 0; i < numverts; i++, vert++) { + BPH_mass_spring_get_motion_state(id, i, vert->x, vert->v); + copy_v3_v3(vert->txold, vert->x); + } + + return 1; +} + +bool BPH_cloth_solver_get_texture_data(Object *UNUSED(ob), ClothModifierData *clmd, VoxelData *vd) +{ + Cloth *cloth = clmd->clothObject; + HairGrid *grid; + float gmin[3], gmax[3]; + + if (!clmd->clothObject || !clmd->clothObject->implicit) + return false; + + hair_get_boundbox(clmd, gmin, gmax); + + grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_cell_size, gmin, gmax); + cloth_continuum_fill_grid(grid, cloth); + + BPH_hair_volume_get_texture_data(grid, vd); + + BPH_hair_volume_free_vertex_grid(grid); + + return true; +} +>>>>>>> local |