tornavis/source/blender/blenkernel/intern/cloth.cc

1910 lines
57 KiB
C++

/* SPDX-FileCopyrightText: Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup bke
*/
#include "MEM_guardedalloc.h"
#include "DNA_cloth_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "BLI_linklist.h"
#include "BLI_math_geom.h"
#include "BLI_math_matrix.h"
#include "BLI_math_rotation.h"
#include "BLI_math_vector.h"
#include "BLI_rand.h"
#include "BLI_utildefines.h"
#include "DEG_depsgraph.hh"
#include "DEG_depsgraph_query.hh"
#include "BKE_bvhutils.hh"
#include "BKE_cloth.hh"
#include "BKE_effect.h"
#include "BKE_global.h"
#include "BKE_lib_id.h"
#include "BKE_mesh.hh"
#include "BKE_mesh_runtime.hh"
#include "BKE_modifier.hh"
#include "BKE_pointcache.h"
#include "SIM_mass_spring.h"
// #include "PIL_time.h" /* timing for debug prints */
/* ********** cloth engine ******* */
/* Prototypes for internal functions.
*/
static void cloth_to_object(Object *ob, ClothModifierData *clmd, float (*vertexCos)[3]);
static void cloth_from_mesh(ClothModifierData *clmd, const Object *ob, Mesh *mesh);
static bool cloth_from_object(
Object *ob, ClothModifierData *clmd, Mesh *mesh, float framenr, int first);
static void cloth_update_springs(ClothModifierData *clmd);
static void cloth_update_verts(Object *ob, ClothModifierData *clmd, Mesh *mesh);
static void cloth_update_spring_lengths(ClothModifierData *clmd, Mesh *mesh);
static bool cloth_build_springs(ClothModifierData *clmd, Mesh *mesh);
static void cloth_apply_vgroup(ClothModifierData *clmd, Mesh *mesh);
struct BendSpringRef {
int index;
int face;
ClothSpring *spring;
};
/******************************************************************************
*
* External interface called by modifier.cc clothModifier functions.
*
******************************************************************************/
static BVHTree *bvhtree_build_from_cloth(ClothModifierData *clmd, float epsilon)
{
if (!clmd) {
return nullptr;
}
Cloth *cloth = clmd->clothObject;
if (!cloth) {
return nullptr;
}
ClothVertex *verts = cloth->verts;
const MVertTri *vt = cloth->tri;
/* in the moment, return zero if no faces there */
if (!cloth->primitive_num) {
return nullptr;
}
/* Create quad-tree with k=26. */
BVHTree *bvhtree = BLI_bvhtree_new(cloth->primitive_num, epsilon, 4, 26);
/* fill tree */
if (clmd->hairdata == nullptr) {
for (int i = 0; i < cloth->primitive_num; i++, vt++) {
float co[3][3];
copy_v3_v3(co[0], verts[vt->tri[0]].xold);
copy_v3_v3(co[1], verts[vt->tri[1]].xold);
copy_v3_v3(co[2], verts[vt->tri[2]].xold);
BLI_bvhtree_insert(bvhtree, i, co[0], 3);
}
}
else {
const blender::int2 *edges = cloth->edges;
for (int i = 0; i < cloth->primitive_num; i++) {
float co[2][3];
copy_v3_v3(co[0], verts[edges[i][0]].xold);
copy_v3_v3(co[1], verts[edges[i][1]].xold);
BLI_bvhtree_insert(bvhtree, i, co[0], 2);
}
}
/* balance tree */
BLI_bvhtree_balance(bvhtree);
return bvhtree;
}
void bvhtree_update_from_cloth(ClothModifierData *clmd, bool moving, bool self)
{
uint i = 0;
Cloth *cloth = clmd->clothObject;
BVHTree *bvhtree;
ClothVertex *verts = cloth->verts;
const MVertTri *vt;
BLI_assert(!(clmd->hairdata != nullptr && self));
if (self) {
bvhtree = cloth->bvhselftree;
}
else {
bvhtree = cloth->bvhtree;
}
if (!bvhtree) {
return;
}
vt = cloth->tri;
/* update vertex position in bvh tree */
if (clmd->hairdata == nullptr) {
if (verts && vt) {
for (i = 0; i < cloth->primitive_num; i++, vt++) {
float co[3][3], co_moving[3][3];
bool ret;
/* copy new locations into array */
if (moving) {
copy_v3_v3(co[0], verts[vt->tri[0]].txold);
copy_v3_v3(co[1], verts[vt->tri[1]].txold);
copy_v3_v3(co[2], verts[vt->tri[2]].txold);
/* update moving positions */
copy_v3_v3(co_moving[0], verts[vt->tri[0]].tx);
copy_v3_v3(co_moving[1], verts[vt->tri[1]].tx);
copy_v3_v3(co_moving[2], verts[vt->tri[2]].tx);
ret = BLI_bvhtree_update_node(bvhtree, i, co[0], co_moving[0], 3);
}
else {
copy_v3_v3(co[0], verts[vt->tri[0]].tx);
copy_v3_v3(co[1], verts[vt->tri[1]].tx);
copy_v3_v3(co[2], verts[vt->tri[2]].tx);
ret = BLI_bvhtree_update_node(bvhtree, i, co[0], nullptr, 3);
}
/* check if tree is already full */
if (ret == false) {
break;
}
}
BLI_bvhtree_update_tree(bvhtree);
}
}
else {
if (verts) {
const blender::int2 *edges = reinterpret_cast<const blender::int2 *>(cloth->edges);
for (i = 0; i < cloth->primitive_num; i++) {
float co[2][3];
copy_v3_v3(co[0], verts[edges[i][0]].tx);
copy_v3_v3(co[1], verts[edges[i][1]].tx);
if (!BLI_bvhtree_update_node(bvhtree, i, co[0], nullptr, 2)) {
break;
}
}
BLI_bvhtree_update_tree(bvhtree);
}
}
}
void cloth_clear_cache(Object *ob, ClothModifierData *clmd, float framenr)
{
PTCacheID pid;
BKE_ptcache_id_from_cloth(&pid, ob, clmd);
/* don't do anything as long as we're in editmode! */
if (pid.cache->edit && ob->mode & OB_MODE_PARTICLE_EDIT) {
return;
}
BKE_ptcache_id_clear(&pid, PTCACHE_CLEAR_AFTER, framenr);
}
static bool do_init_cloth(Object *ob, ClothModifierData *clmd, Mesh *result, int framenr)
{
PointCache *cache;
cache = clmd->point_cache;
/* initialize simulation data if it didn't exist already */
if (clmd->clothObject == nullptr) {
if (!cloth_from_object(ob, clmd, result, framenr, 1)) {
BKE_ptcache_invalidate(cache);
BKE_modifier_set_error(ob, &(clmd->modifier), "Can't initialize cloth");
return false;
}
if (clmd->clothObject == nullptr) {
BKE_ptcache_invalidate(cache);
BKE_modifier_set_error(ob, &(clmd->modifier), "Null cloth object");
return false;
}
SIM_cloth_solver_set_positions(clmd);
ClothSimSettings *parms = clmd->sim_parms;
if (parms->flags & CLOTH_SIMSETTINGS_FLAG_PRESSURE &&
!(parms->flags & CLOTH_SIMSETTINGS_FLAG_PRESSURE_VOL))
{
SIM_cloth_solver_set_volume(clmd);
}
clmd->clothObject->last_frame = MINFRAME - 1;
clmd->sim_parms->dt = 1.0f / clmd->sim_parms->stepsPerFrame;
}
return true;
}
static int do_step_cloth(
Depsgraph *depsgraph, Object *ob, ClothModifierData *clmd, Mesh *result, int framenr)
{
using namespace blender;
/* simulate 1 frame forward */
ClothVertex *verts = nullptr;
Cloth *cloth;
ListBase *effectors = nullptr;
uint i = 0;
int ret = 0;
bool vert_mass_changed = false;
cloth = clmd->clothObject;
verts = cloth->verts;
const Span<float3> positions = result->vert_positions();
vert_mass_changed = verts->mass != clmd->sim_parms->mass;
/* force any pinned verts to their constrained location. */
for (i = 0; i < clmd->clothObject->mvert_num; i++, verts++) {
/* save the previous position. */
copy_v3_v3(verts->xold, verts->xconst);
copy_v3_v3(verts->txold, verts->x);
/* Get the current position. */
copy_v3_v3(verts->xconst, positions[i]);
mul_m4_v3(ob->object_to_world, verts->xconst);
if (vert_mass_changed) {
verts->mass = clmd->sim_parms->mass;
SIM_mass_spring_set_implicit_vertex_mass(cloth->implicit, i, verts->mass);
}
}
effectors = BKE_effectors_create(
depsgraph, ob, nullptr, clmd->sim_parms->effector_weights, false);
if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_DYNAMIC_BASEMESH) {
cloth_update_verts(ob, clmd, result);
}
/* Support for dynamic vertex groups, changing from frame to frame */
cloth_apply_vgroup(clmd, result);
if ((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_DYNAMIC_BASEMESH) ||
(clmd->sim_parms->vgroup_shrink > 0) || (clmd->sim_parms->shrink_min != 0.0f))
{
cloth_update_spring_lengths(clmd, result);
}
cloth_update_springs(clmd);
// TIMEIT_START(cloth_step)
/* call the solver. */
ret = SIM_cloth_solve(depsgraph, ob, framenr, clmd, effectors);
// TIMEIT_END(cloth_step)
BKE_effectors_free(effectors);
// printf ( "%f\n", ( float ) tval() );
return ret;
}
/************************************************
* clothModifier_do - main simulation function
************************************************/
void clothModifier_do(ClothModifierData *clmd,
Depsgraph *depsgraph,
Scene *scene,
Object *ob,
Mesh *mesh,
float (*vertexCos)[3])
{
PointCache *cache;
PTCacheID pid;
float timescale;
int framenr, startframe, endframe;
int cache_result;
framenr = DEG_get_ctime(depsgraph);
cache = clmd->point_cache;
BKE_ptcache_id_from_cloth(&pid, ob, clmd);
BKE_ptcache_id_time(&pid, scene, framenr, &startframe, &endframe, &timescale);
clmd->sim_parms->timescale = timescale * clmd->sim_parms->time_scale;
if (clmd->sim_parms->reset ||
(clmd->clothObject && mesh->totvert != clmd->clothObject->mvert_num)) {
clmd->sim_parms->reset = 0;
cache->flag |= PTCACHE_OUTDATED;
BKE_ptcache_id_reset(scene, &pid, PTCACHE_RESET_OUTDATED);
BKE_ptcache_validate(cache, 0);
cache->last_exact = 0;
cache->flag &= ~PTCACHE_REDO_NEEDED;
}
/* simulation is only active during a specific period */
if (framenr < startframe) {
BKE_ptcache_invalidate(cache);
return;
}
if (framenr > endframe) {
framenr = endframe;
}
/* initialize simulation data if it didn't exist already */
if (!do_init_cloth(ob, clmd, mesh, framenr)) {
return;
}
if (framenr == startframe) {
BKE_ptcache_id_reset(scene, &pid, PTCACHE_RESET_OUTDATED);
do_init_cloth(ob, clmd, mesh, framenr);
BKE_ptcache_validate(cache, framenr);
cache->flag &= ~PTCACHE_REDO_NEEDED;
clmd->clothObject->last_frame = framenr;
return;
}
/* Since implicit sharing is introduced, mesh data can be moved to other places.
* Therefore some fields in simulation data need to be updated accordingly */
clmd->clothObject->edges = mesh->edges().data();
/* try to read from cache */
bool can_simulate = (framenr == clmd->clothObject->last_frame + 1) &&
!(cache->flag & PTCACHE_BAKED);
cache_result = BKE_ptcache_read(&pid, float(framenr) + scene->r.subframe, can_simulate);
if (cache_result == PTCACHE_READ_EXACT || cache_result == PTCACHE_READ_INTERPOLATED ||
(!can_simulate && cache_result == PTCACHE_READ_OLD))
{
SIM_cloth_solver_set_positions(clmd);
cloth_to_object(ob, clmd, vertexCos);
BKE_ptcache_validate(cache, framenr);
if (cache_result == PTCACHE_READ_INTERPOLATED && cache->flag & PTCACHE_REDO_NEEDED) {
BKE_ptcache_write(&pid, framenr);
}
clmd->clothObject->last_frame = framenr;
return;
}
if (cache_result == PTCACHE_READ_OLD) {
SIM_cloth_solver_set_positions(clmd);
}
else if (
/* 2.4x disabled lib, but this can be used in some cases, testing further - campbell */
/*ob->id.lib ||*/ (cache->flag & PTCACHE_BAKED))
{
/* if baked and nothing in cache, do nothing */
BKE_ptcache_invalidate(cache);
return;
}
/* if on second frame, write cache for first frame */
if (cache->simframe == startframe && (cache->flag & PTCACHE_OUTDATED || cache->last_exact == 0))
{
BKE_ptcache_write(&pid, startframe);
}
clmd->sim_parms->timescale *= framenr - cache->simframe;
/* do simulation */
BKE_ptcache_validate(cache, framenr);
if (!do_step_cloth(depsgraph, ob, clmd, mesh, framenr)) {
BKE_ptcache_invalidate(cache);
}
else {
BKE_ptcache_write(&pid, framenr);
}
cloth_to_object(ob, clmd, vertexCos);
clmd->clothObject->last_frame = framenr;
}
void cloth_free_modifier(ClothModifierData *clmd)
{
Cloth *cloth = nullptr;
if (!clmd) {
return;
}
cloth = clmd->clothObject;
if (cloth) {
SIM_cloth_solver_free(clmd);
/* Free the verts. */
MEM_SAFE_FREE(cloth->verts);
cloth->mvert_num = 0;
/* Free the springs. */
if (cloth->springs != nullptr) {
LinkNode *search = cloth->springs;
while (search) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
MEM_SAFE_FREE(spring->pa);
MEM_SAFE_FREE(spring->pb);
MEM_freeN(spring);
search = search->next;
}
BLI_linklist_free(cloth->springs, nullptr);
cloth->springs = nullptr;
}
cloth->springs = nullptr;
cloth->numsprings = 0;
/* free BVH collision tree */
if (cloth->bvhtree) {
BLI_bvhtree_free(cloth->bvhtree);
}
if (cloth->bvhselftree && cloth->bvhselftree != cloth->bvhtree) {
BLI_bvhtree_free(cloth->bvhselftree);
}
/* we save our faces for collision objects */
if (cloth->tri) {
MEM_freeN(cloth->tri);
}
#if 0
if (clmd->clothObject->facemarks) {
MEM_freeN(clmd->clothObject->facemarks);
}
#endif
MEM_delete(cloth);
clmd->clothObject = nullptr;
}
}
void cloth_free_modifier_extern(ClothModifierData *clmd)
{
Cloth *cloth = nullptr;
if (G.debug & G_DEBUG_SIMDATA) {
printf("cloth_free_modifier_extern\n");
}
if (!clmd) {
return;
}
cloth = clmd->clothObject;
if (cloth) {
if (G.debug & G_DEBUG_SIMDATA) {
printf("cloth_free_modifier_extern in\n");
}
SIM_cloth_solver_free(clmd);
/* Free the verts. */
MEM_SAFE_FREE(cloth->verts);
cloth->mvert_num = 0;
/* Free the springs. */
if (cloth->springs != nullptr) {
LinkNode *search = cloth->springs;
while (search) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
MEM_SAFE_FREE(spring->pa);
MEM_SAFE_FREE(spring->pb);
MEM_freeN(spring);
search = search->next;
}
BLI_linklist_free(cloth->springs, nullptr);
cloth->springs = nullptr;
}
cloth->springs = nullptr;
cloth->numsprings = 0;
/* free BVH collision tree */
if (cloth->bvhtree) {
BLI_bvhtree_free(cloth->bvhtree);
}
if (cloth->bvhselftree && cloth->bvhselftree != cloth->bvhtree) {
BLI_bvhtree_free(cloth->bvhselftree);
}
/* we save our faces for collision objects */
if (cloth->tri) {
MEM_freeN(cloth->tri);
}
#if 0
if (clmd->clothObject->facemarks) {
MEM_freeN(clmd->clothObject->facemarks);
}
#endif
MEM_delete(cloth);
clmd->clothObject = nullptr;
}
}
/******************************************************************************
*
* Internal functions.
*
******************************************************************************/
/**
* Copies the deformed vertices to the object.
*/
static void cloth_to_object(Object *ob, ClothModifierData *clmd, float (*vertexCos)[3])
{
uint i = 0;
Cloth *cloth = clmd->clothObject;
if (clmd->clothObject) {
/* Inverse matrix is not up to date. */
invert_m4_m4(ob->world_to_object, ob->object_to_world);
for (i = 0; i < cloth->mvert_num; i++) {
copy_v3_v3(vertexCos[i], cloth->verts[i].x);
mul_m4_v3(ob->world_to_object, vertexCos[i]); /* cloth is in global coords */
}
}
}
int cloth_uses_vgroup(ClothModifierData *clmd)
{
return (((clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_SELF) &&
(clmd->coll_parms->vgroup_selfcol > 0)) ||
((clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_ENABLED) &&
(clmd->coll_parms->vgroup_objcol > 0)) ||
(clmd->sim_parms->vgroup_pressure > 0) || (clmd->sim_parms->vgroup_struct > 0) ||
(clmd->sim_parms->vgroup_bend > 0) || (clmd->sim_parms->vgroup_shrink > 0) ||
(clmd->sim_parms->vgroup_intern > 0) || (clmd->sim_parms->vgroup_mass > 0));
}
/**
* Applies a vertex group as specified by type.
*/
static void cloth_apply_vgroup(ClothModifierData *clmd, Mesh *mesh)
{
if (!clmd || !mesh) {
return;
}
int mvert_num = mesh->totvert;
ClothVertex *verts = clmd->clothObject->verts;
const blender::Span<MDeformVert> dverts = mesh->deform_verts();
if (cloth_uses_vgroup(clmd)) {
for (int i = 0; i < mvert_num; i++, verts++) {
/* Reset Goal values to standard */
if (clmd->sim_parms->vgroup_mass > 0) {
verts->goal = clmd->sim_parms->defgoal;
}
else {
verts->goal = 0.0f;
}
/* Compute base cloth shrink weight */
verts->shrink_factor = 0.0f;
/* Reset vertex flags */
verts->flags &= ~(CLOTH_VERT_FLAG_PINNED | CLOTH_VERT_FLAG_NOSELFCOLL |
CLOTH_VERT_FLAG_NOOBJCOLL);
if (!dverts.is_empty()) {
const MDeformVert *dvert = &dverts[i];
for (int j = 0; j < dvert->totweight; j++) {
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_mass - 1)) {
verts->goal = dvert->dw[j].weight;
// goalfac = 1.0f; /* UNUSED */
/* Kicking goal factor to simplify things...who uses that anyway? */
// ABS (clmd->sim_parms->maxgoal - clmd->sim_parms->mingoal);
verts->goal = pow4f(verts->goal);
if (verts->goal >= SOFTGOALSNAP) {
verts->flags |= CLOTH_VERT_FLAG_PINNED;
}
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_struct - 1)) {
verts->struct_stiff = dvert->dw[j].weight;
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_shear - 1)) {
verts->shear_stiff = dvert->dw[j].weight;
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_bend - 1)) {
verts->bend_stiff = dvert->dw[j].weight;
}
if (dvert->dw[j].def_nr == (clmd->coll_parms->vgroup_selfcol - 1)) {
if (dvert->dw[j].weight > 0.0f) {
verts->flags |= CLOTH_VERT_FLAG_NOSELFCOLL;
}
}
if (dvert->dw[j].def_nr == (clmd->coll_parms->vgroup_objcol - 1)) {
if (dvert->dw[j].weight > 0.0f) {
verts->flags |= CLOTH_VERT_FLAG_NOOBJCOLL;
}
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_shrink - 1)) {
/* Used for linear interpolation between min and max
* shrink factor based on weight. */
verts->shrink_factor = dvert->dw[j].weight;
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_intern - 1)) {
/* Used to define the stiffness weight on the internal spring connected to this vertex.
*/
verts->internal_stiff = dvert->dw[j].weight;
}
if (dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_pressure - 1)) {
/* Used to define how much the pressure settings should affect the given vertex. */
verts->pressure_factor = dvert->dw[j].weight;
}
}
}
}
}
}
static float cloth_shrink_factor(ClothModifierData *clmd, ClothVertex *verts, int i1, int i2)
{
/* Linear interpolation between min and max shrink factor based on weight. */
float base = 1.0f - clmd->sim_parms->shrink_min;
float shrink_factor_delta = clmd->sim_parms->shrink_min - clmd->sim_parms->shrink_max;
float k1 = base + shrink_factor_delta * verts[i1].shrink_factor;
float k2 = base + shrink_factor_delta * verts[i2].shrink_factor;
/* Use geometrical mean to average two factors since it behaves better
* for diagonals when a rectangle transforms into a trapezoid. */
return sqrtf(k1 * k2);
}
static bool cloth_from_object(
Object *ob, ClothModifierData *clmd, Mesh *mesh, float /*framenr*/, int first)
{
using namespace blender;
int i = 0;
ClothVertex *verts = nullptr;
const float(*shapekey_rest)[3] = nullptr;
const float tnull[3] = {0, 0, 0};
/* If we have a clothObject, free it. */
if (clmd->clothObject != nullptr) {
cloth_free_modifier(clmd);
if (G.debug & G_DEBUG_SIMDATA) {
printf("cloth_free_modifier cloth_from_object\n");
}
}
/* Allocate a new cloth object. */
clmd->clothObject = MEM_new<Cloth>(__func__);
if (clmd->clothObject) {
clmd->clothObject->old_solver_type = 255;
}
else {
BKE_modifier_set_error(ob, &(clmd->modifier), "Out of memory on allocating clmd->clothObject");
return false;
}
/* mesh input objects need Mesh */
if (!mesh) {
return false;
}
cloth_from_mesh(clmd, ob, mesh);
/* create springs */
clmd->clothObject->springs = nullptr;
clmd->clothObject->numsprings = -1;
if (clmd->sim_parms->shapekey_rest &&
!(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_DYNAMIC_BASEMESH))
{
shapekey_rest = static_cast<const float(*)[3]>(
CustomData_get_layer(&mesh->vert_data, CD_CLOTH_ORCO));
}
const Span<float3> positions = mesh->vert_positions();
verts = clmd->clothObject->verts;
/* set initial values */
for (i = 0; i < mesh->totvert; i++, verts++) {
if (first) {
copy_v3_v3(verts->x, positions[i]);
mul_m4_v3(ob->object_to_world, verts->x);
if (shapekey_rest) {
copy_v3_v3(verts->xrest, shapekey_rest[i]);
mul_m4_v3(ob->object_to_world, verts->xrest);
}
else {
copy_v3_v3(verts->xrest, verts->x);
}
}
/* no GUI interface yet */
verts->mass = clmd->sim_parms->mass;
verts->impulse_count = 0;
if (clmd->sim_parms->vgroup_mass > 0) {
verts->goal = clmd->sim_parms->defgoal;
}
else {
verts->goal = 0.0f;
}
verts->shrink_factor = 0.0f;
verts->flags = 0;
copy_v3_v3(verts->xold, verts->x);
copy_v3_v3(verts->xconst, verts->x);
copy_v3_v3(verts->txold, verts->x);
copy_v3_v3(verts->tx, verts->x);
mul_v3_fl(verts->v, 0.0f);
verts->impulse_count = 0;
copy_v3_v3(verts->impulse, tnull);
}
/* apply / set vertex groups */
/* has to be happen before springs are build! */
cloth_apply_vgroup(clmd, mesh);
if (!cloth_build_springs(clmd, mesh)) {
cloth_free_modifier(clmd);
BKE_modifier_set_error(ob, &(clmd->modifier), "Cannot build springs");
return false;
}
/* init our solver */
SIM_cloth_solver_init(ob, clmd);
if (!first) {
SIM_cloth_solver_set_positions(clmd);
}
clmd->clothObject->bvhtree = bvhtree_build_from_cloth(clmd, clmd->coll_parms->epsilon);
if (compare_ff(clmd->coll_parms->selfepsilon, clmd->coll_parms->epsilon, 1e-6f)) {
/* Share the BVH tree if the epsilon is the same. */
clmd->clothObject->bvhselftree = clmd->clothObject->bvhtree;
}
else {
clmd->clothObject->bvhselftree = bvhtree_build_from_cloth(clmd, clmd->coll_parms->selfepsilon);
}
return true;
}
static void cloth_from_mesh(ClothModifierData *clmd, const Object *ob, Mesh *mesh)
{
const blender::Span<int> corner_verts = mesh->corner_verts();
const blender::Span<MLoopTri> looptris = mesh->looptris();
const uint mvert_num = mesh->totvert;
/* Allocate our vertices. */
clmd->clothObject->mvert_num = mvert_num;
clmd->clothObject->verts = MEM_cnew_array<ClothVertex>(clmd->clothObject->mvert_num, __func__);
if (clmd->clothObject->verts == nullptr) {
cloth_free_modifier(clmd);
BKE_modifier_set_error(
ob, &(clmd->modifier), "Out of memory on allocating clmd->clothObject->verts");
printf("cloth_free_modifier clmd->clothObject->verts\n");
return;
}
/* save face information */
if (clmd->hairdata == nullptr) {
clmd->clothObject->primitive_num = looptris.size();
}
else {
clmd->clothObject->primitive_num = mesh->totedge;
}
clmd->clothObject->tri = static_cast<MVertTri *>(
MEM_malloc_arrayN(looptris.size(), sizeof(MVertTri), __func__));
if (clmd->clothObject->tri == nullptr) {
cloth_free_modifier(clmd);
BKE_modifier_set_error(
ob, &(clmd->modifier), "Out of memory on allocating clmd->clothObject->looptri");
printf("cloth_free_modifier clmd->clothObject->looptri\n");
return;
}
BKE_mesh_runtime_verttri_from_looptri(
clmd->clothObject->tri, corner_verts.data(), looptris.data(), looptris.size());
clmd->clothObject->edges = mesh->edges().data();
/* Free the springs since they can't be correct if the vertices
* changed.
*/
if (clmd->clothObject->springs != nullptr) {
MEM_freeN(clmd->clothObject->springs);
}
}
/* -------------------------------------------------------------------- */
/** \name Spring Network Building Implementation
* \{ */
BLI_INLINE void spring_verts_ordered_set(ClothSpring *spring, int v0, int v1)
{
if (v0 < v1) {
spring->ij = v0;
spring->kl = v1;
}
else {
spring->ij = v1;
spring->kl = v0;
}
}
static void cloth_free_edgelist(LinkNodePair *edgelist, uint mvert_num)
{
if (edgelist) {
for (uint i = 0; i < mvert_num; i++) {
BLI_linklist_free(edgelist[i].list, nullptr);
}
MEM_freeN(edgelist);
}
}
static void cloth_free_errorsprings(Cloth *cloth,
LinkNodePair *edgelist,
BendSpringRef *spring_ref)
{
if (cloth->springs != nullptr) {
LinkNode *search = cloth->springs;
while (search) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
MEM_SAFE_FREE(spring->pa);
MEM_SAFE_FREE(spring->pb);
MEM_freeN(spring);
search = search->next;
}
BLI_linklist_free(cloth->springs, nullptr);
cloth->springs = nullptr;
}
cloth_free_edgelist(edgelist, cloth->mvert_num);
MEM_SAFE_FREE(spring_ref);
cloth->edgeset.clear_and_shrink();
}
BLI_INLINE void cloth_bend_poly_dir(
ClothVertex *verts, int i, int j, const int *inds, int len, float r_dir[3])
{
float cent[3] = {0};
float fact = 1.0f / len;
for (int x = 0; x < len; x++) {
madd_v3_v3fl(cent, verts[inds[x]].xrest, fact);
}
normal_tri_v3(r_dir, verts[i].xrest, verts[j].xrest, cent);
}
static float cloth_spring_angle(
ClothVertex *verts, int i, int j, int *i_a, int *i_b, int len_a, int len_b)
{
float dir_a[3], dir_b[3];
float tmp[3], vec_e[3];
float sin, cos;
/* Poly vectors. */
cloth_bend_poly_dir(verts, j, i, i_a, len_a, dir_a);
cloth_bend_poly_dir(verts, i, j, i_b, len_b, dir_b);
/* Edge vector. */
sub_v3_v3v3(vec_e, verts[i].xrest, verts[j].xrest);
normalize_v3(vec_e);
/* Compute angle. */
cos = dot_v3v3(dir_a, dir_b);
cross_v3_v3v3(tmp, dir_a, dir_b);
sin = dot_v3v3(tmp, vec_e);
return atan2f(sin, cos);
}
static void cloth_hair_update_bending_targets(ClothModifierData *clmd)
{
Cloth *cloth = clmd->clothObject;
LinkNode *search = nullptr;
float hair_frame[3][3], dir_old[3], dir_new[3];
int prev_mn; /* to find hair chains */
if (!clmd->hairdata) {
return;
}
/* XXX NOTE: we need to propagate frames from the root up,
* but structural hair springs are stored in reverse order.
* The bending springs however are then inserted in the same
* order as vertices again ...
* This messy situation can be resolved when solver data is
* generated directly from a dedicated hair system.
*/
prev_mn = -1;
for (search = cloth->springs; search; search = search->next) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
ClothHairData *hair_ij, *hair_kl;
bool is_root = spring->kl != prev_mn;
if (spring->type != CLOTH_SPRING_TYPE_BENDING_HAIR) {
continue;
}
hair_ij = &clmd->hairdata[spring->ij];
hair_kl = &clmd->hairdata[spring->kl];
if (is_root) {
/* initial hair frame from root orientation */
copy_m3_m3(hair_frame, hair_ij->rot);
/* surface normal is the initial direction,
* parallel transport then keeps it aligned to the hair direction
*/
copy_v3_v3(dir_new, hair_frame[2]);
}
copy_v3_v3(dir_old, dir_new);
sub_v3_v3v3(dir_new, cloth->verts[spring->mn].x, cloth->verts[spring->kl].x);
normalize_v3(dir_new);
/* get local targets for kl/mn vertices by putting rest targets into the current frame,
* then multiply with the rest length to get the actual goals
*/
mul_v3_m3v3(spring->target, hair_frame, hair_kl->rest_target);
mul_v3_fl(spring->target, spring->restlen);
/* move frame to next hair segment */
cloth_parallel_transport_hair_frame(hair_frame, dir_old, dir_new);
prev_mn = spring->mn;
}
}
static void cloth_hair_update_bending_rest_targets(ClothModifierData *clmd)
{
Cloth *cloth = clmd->clothObject;
LinkNode *search = nullptr;
float hair_frame[3][3], dir_old[3], dir_new[3];
int prev_mn; /* to find hair roots */
if (!clmd->hairdata) {
return;
}
/* XXX NOTE: we need to propagate frames from the root up,
* but structural hair springs are stored in reverse order.
* The bending springs however are then inserted in the same
* order as vertices again ...
* This messy situation can be resolved when solver data is
* generated directly from a dedicated hair system.
*/
prev_mn = -1;
for (search = cloth->springs; search; search = search->next) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
ClothHairData *hair_ij, *hair_kl;
bool is_root = spring->kl != prev_mn;
if (spring->type != CLOTH_SPRING_TYPE_BENDING_HAIR) {
continue;
}
hair_ij = &clmd->hairdata[spring->ij];
hair_kl = &clmd->hairdata[spring->kl];
if (is_root) {
/* initial hair frame from root orientation */
copy_m3_m3(hair_frame, hair_ij->rot);
/* surface normal is the initial direction,
* parallel transport then keeps it aligned to the hair direction
*/
copy_v3_v3(dir_new, hair_frame[2]);
}
copy_v3_v3(dir_old, dir_new);
sub_v3_v3v3(dir_new, cloth->verts[spring->mn].xrest, cloth->verts[spring->kl].xrest);
normalize_v3(dir_new);
/* dir expressed in the hair frame defines the rest target direction */
copy_v3_v3(hair_kl->rest_target, dir_new);
mul_transposed_m3_v3(hair_frame, hair_kl->rest_target);
/* move frame to next hair segment */
cloth_parallel_transport_hair_frame(hair_frame, dir_old, dir_new);
prev_mn = spring->mn;
}
}
/* update stiffness if vertex group values are changing from frame to frame */
static void cloth_update_springs(ClothModifierData *clmd)
{
Cloth *cloth = clmd->clothObject;
LinkNode *search = nullptr;
search = cloth->springs;
while (search) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
spring->lin_stiffness = 0.0f;
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
if (spring->type & CLOTH_SPRING_TYPE_BENDING) {
spring->ang_stiffness = (cloth->verts[spring->kl].bend_stiff +
cloth->verts[spring->ij].bend_stiff) /
2.0f;
}
}
if (spring->type & CLOTH_SPRING_TYPE_STRUCTURAL) {
spring->lin_stiffness = (cloth->verts[spring->kl].struct_stiff +
cloth->verts[spring->ij].struct_stiff) /
2.0f;
}
else if (spring->type & CLOTH_SPRING_TYPE_SHEAR) {
spring->lin_stiffness = (cloth->verts[spring->kl].shear_stiff +
cloth->verts[spring->ij].shear_stiff) /
2.0f;
}
else if (spring->type == CLOTH_SPRING_TYPE_BENDING) {
spring->lin_stiffness = (cloth->verts[spring->kl].bend_stiff +
cloth->verts[spring->ij].bend_stiff) /
2.0f;
}
else if (spring->type & CLOTH_SPRING_TYPE_INTERNAL) {
spring->lin_stiffness = (cloth->verts[spring->kl].internal_stiff +
cloth->verts[spring->ij].internal_stiff) /
2.0f;
}
else if (spring->type == CLOTH_SPRING_TYPE_BENDING_HAIR) {
ClothVertex *v1 = &cloth->verts[spring->ij];
ClothVertex *v2 = &cloth->verts[spring->kl];
if (clmd->hairdata) {
/* copy extra hair data to generic cloth vertices */
v1->bend_stiff = clmd->hairdata[spring->ij].bending_stiffness;
v2->bend_stiff = clmd->hairdata[spring->kl].bending_stiffness;
}
spring->lin_stiffness = (v1->bend_stiff + v2->bend_stiff) / 2.0f;
}
else if (spring->type == CLOTH_SPRING_TYPE_GOAL) {
/* WARNING: Appending NEW goal springs does not work
* because implicit solver would need reset! */
/* Activate / Deactivate existing springs */
if (!(cloth->verts[spring->ij].flags & CLOTH_VERT_FLAG_PINNED) &&
(cloth->verts[spring->ij].goal > ALMOST_ZERO))
{
spring->flags &= ~CLOTH_SPRING_FLAG_DEACTIVATE;
}
else {
spring->flags |= CLOTH_SPRING_FLAG_DEACTIVATE;
}
}
search = search->next;
}
cloth_hair_update_bending_targets(clmd);
}
/* Update rest verts, for dynamically deformable cloth */
static void cloth_update_verts(Object *ob, ClothModifierData *clmd, Mesh *mesh)
{
using namespace blender;
uint i = 0;
const Span<float3> positions = mesh->vert_positions();
ClothVertex *verts = clmd->clothObject->verts;
/* vertex count is already ensured to match */
for (i = 0; i < mesh->totvert; i++, verts++) {
copy_v3_v3(verts->xrest, positions[i]);
mul_m4_v3(ob->object_to_world, verts->xrest);
}
}
/* Write rest vert locations to a copy of the mesh. */
static Mesh *cloth_make_rest_mesh(ClothModifierData *clmd, Mesh *mesh)
{
using namespace blender;
Mesh *new_mesh = BKE_mesh_copy_for_eval(mesh);
ClothVertex *verts = clmd->clothObject->verts;
MutableSpan<float3> positions = mesh->vert_positions_for_write();
/* vertex count is already ensured to match */
for (const int i : positions.index_range()) {
positions[i] = verts[i].xrest;
}
BKE_mesh_tag_positions_changed(new_mesh);
return new_mesh;
}
/* Update spring rest length, for dynamically deformable cloth */
static void cloth_update_spring_lengths(ClothModifierData *clmd, Mesh *mesh)
{
Cloth *cloth = clmd->clothObject;
LinkNode *search = cloth->springs;
uint struct_springs = 0;
uint i = 0;
uint mvert_num = uint(mesh->totvert);
float shrink_factor;
clmd->sim_parms->avg_spring_len = 0.0f;
for (i = 0; i < mvert_num; i++) {
cloth->verts[i].avg_spring_len = 0.0f;
}
while (search) {
ClothSpring *spring = static_cast<ClothSpring *>(search->link);
if (spring->type != CLOTH_SPRING_TYPE_SEWING) {
if (spring->type & (CLOTH_SPRING_TYPE_STRUCTURAL | CLOTH_SPRING_TYPE_SHEAR |
CLOTH_SPRING_TYPE_BENDING | CLOTH_SPRING_TYPE_INTERNAL))
{
shrink_factor = cloth_shrink_factor(clmd, cloth->verts, spring->ij, spring->kl);
}
else {
shrink_factor = 1.0f;
}
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest, cloth->verts[spring->ij].xrest) *
shrink_factor;
if (spring->type & CLOTH_SPRING_TYPE_BENDING) {
spring->restang = cloth_spring_angle(
cloth->verts, spring->ij, spring->kl, spring->pa, spring->pb, spring->la, spring->lb);
}
}
if (spring->type & CLOTH_SPRING_TYPE_STRUCTURAL) {
clmd->sim_parms->avg_spring_len += spring->restlen;
cloth->verts[spring->ij].avg_spring_len += spring->restlen;
cloth->verts[spring->kl].avg_spring_len += spring->restlen;
struct_springs++;
}
search = search->next;
}
if (struct_springs > 0) {
clmd->sim_parms->avg_spring_len /= struct_springs;
}
for (i = 0; i < mvert_num; i++) {
if (cloth->verts[i].spring_count > 0) {
cloth->verts[i].avg_spring_len = cloth->verts[i].avg_spring_len * 0.49f /
float(cloth->verts[i].spring_count);
}
}
}
BLI_INLINE void cross_identity_v3(float r[3][3], const float v[3])
{
zero_m3(r);
r[0][1] = v[2];
r[0][2] = -v[1];
r[1][0] = -v[2];
r[1][2] = v[0];
r[2][0] = v[1];
r[2][1] = -v[0];
}
BLI_INLINE void madd_m3_m3fl(float r[3][3], const float m[3][3], float f)
{
r[0][0] += m[0][0] * f;
r[0][1] += m[0][1] * f;
r[0][2] += m[0][2] * f;
r[1][0] += m[1][0] * f;
r[1][1] += m[1][1] * f;
r[1][2] += m[1][2] * f;
r[2][0] += m[2][0] * f;
r[2][1] += m[2][1] * f;
r[2][2] += m[2][2] * f;
}
void cloth_parallel_transport_hair_frame(float mat[3][3],
const float dir_old[3],
const float dir_new[3])
{
float rot[3][3];
/* rotation between segments */
rotation_between_vecs_to_mat3(rot, dir_old, dir_new);
/* rotate the frame */
mul_m3_m3m3(mat, rot, mat);
}
/* Add a shear and a bend spring between two verts within a face. */
static bool cloth_add_shear_bend_spring(ClothModifierData *clmd,
LinkNodePair *edgelist,
const blender::Span<int> corner_verts,
const blender::OffsetIndices<int> faces,
int i,
int j,
int k)
{
Cloth *cloth = clmd->clothObject;
ClothSpring *spring;
const int *tmp_corner;
float shrink_factor;
int x, y;
/* Combined shear/bend properties. */
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (!spring) {
return false;
}
spring_verts_ordered_set(spring, corner_verts[faces[i][j]], corner_verts[faces[i][k]]);
shrink_factor = cloth_shrink_factor(clmd, cloth->verts, spring->ij, spring->kl);
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest, cloth->verts[spring->ij].xrest) *
shrink_factor;
spring->type |= CLOTH_SPRING_TYPE_SHEAR;
spring->lin_stiffness = (cloth->verts[spring->kl].shear_stiff +
cloth->verts[spring->ij].shear_stiff) /
2.0f;
if (edgelist) {
BLI_linklist_append(&edgelist[spring->ij], spring);
BLI_linklist_append(&edgelist[spring->kl], spring);
}
/* Bending specific properties. */
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
spring->type |= CLOTH_SPRING_TYPE_BENDING;
spring->la = k - j + 1;
spring->lb = faces[i].size() - k + j + 1;
spring->pa = static_cast<int *>(MEM_mallocN(sizeof(*spring->pa) * spring->la, "spring poly"));
if (!spring->pa) {
return false;
}
spring->pb = static_cast<int *>(MEM_mallocN(sizeof(*spring->pb) * spring->lb, "spring poly"));
if (!spring->pb) {
return false;
}
tmp_corner = &corner_verts[faces[i].start()];
for (x = 0; x < spring->la; x++) {
spring->pa[x] = tmp_corner[j + x];
}
for (x = 0; x <= j; x++) {
spring->pb[x] = tmp_corner[x];
}
for (y = k; y < faces[i].size(); x++, y++) {
spring->pb[x] = tmp_corner[y];
}
spring->mn = -1;
spring->restang = cloth_spring_angle(
cloth->verts, spring->ij, spring->kl, spring->pa, spring->pb, spring->la, spring->lb);
spring->ang_stiffness = (cloth->verts[spring->ij].bend_stiff +
cloth->verts[spring->kl].bend_stiff) /
2.0f;
}
BLI_linklist_prepend(&cloth->springs, spring);
return true;
}
BLI_INLINE bool cloth_bend_set_poly_vert_array(int **poly, int len, const int *corner_verts)
{
int *p = static_cast<int *>(MEM_mallocN(sizeof(int) * len, "spring poly"));
if (!p) {
return false;
}
for (int i = 0; i < len; i++) {
p[i] = corner_verts[i];
}
*poly = p;
return true;
}
static bool find_internal_spring_target_vertex(BVHTreeFromMesh *treedata,
const blender::Span<blender::float3> vert_normals,
uint v_idx,
RNG *rng,
float max_length,
float max_diversion,
bool check_normal,
int *r_tar_v_idx)
{
float co[3], no[3], new_co[3];
float radius;
copy_v3_v3(co, treedata->vert_positions[v_idx]);
negate_v3_v3(no, vert_normals[v_idx]);
float vec_len = sin(max_diversion);
float offset[3];
offset[0] = 0.5f - BLI_rng_get_float(rng);
offset[1] = 0.5f - BLI_rng_get_float(rng);
offset[2] = 0.5f - BLI_rng_get_float(rng);
normalize_v3(offset);
mul_v3_fl(offset, vec_len);
add_v3_v3(no, offset);
normalize_v3(no);
/* Nudge the start point so we do not hit it with the ray. */
copy_v3_v3(new_co, no);
mul_v3_fl(new_co, FLT_EPSILON);
add_v3_v3(new_co, co);
radius = 0.0f;
if (max_length == 0.0f) {
max_length = FLT_MAX;
}
BVHTreeRayHit rayhit = {0};
rayhit.index = -1;
rayhit.dist = max_length;
BLI_bvhtree_ray_cast(
treedata->tree, new_co, no, radius, &rayhit, treedata->raycast_callback, treedata);
int vert_idx = -1;
const int *corner_verts = treedata->corner_verts;
const MLoopTri *lt = nullptr;
if (rayhit.index != -1 && rayhit.dist <= max_length) {
if (check_normal && dot_v3v3(rayhit.no, no) < 0.0f) {
/* We hit a point that points in the same direction as our starting point. */
return false;
}
float min_len = FLT_MAX;
lt = &treedata->looptri[rayhit.index];
for (int i = 0; i < 3; i++) {
int tmp_vert_idx = corner_verts[lt->tri[i]];
if (tmp_vert_idx == v_idx) {
/* We managed to hit ourselves. */
return false;
}
float len = len_v3v3(co, rayhit.co);
if (len < min_len) {
min_len = len;
vert_idx = tmp_vert_idx;
}
}
*r_tar_v_idx = vert_idx;
return true;
}
return false;
}
static bool cloth_build_springs(ClothModifierData *clmd, Mesh *mesh)
{
using namespace blender;
using namespace blender::bke;
Cloth *cloth = clmd->clothObject;
ClothSpring *spring = nullptr, *tspring = nullptr, *tspring2 = nullptr;
uint struct_springs = 0, shear_springs = 0, bend_springs = 0, struct_springs_real = 0;
uint mvert_num = uint(mesh->totvert);
uint numedges = uint(mesh->totedge);
uint numface = uint(mesh->faces_num);
float shrink_factor;
const blender::Span<int2> edges = mesh->edges();
const OffsetIndices faces = mesh->faces();
const Span<int> corner_verts = mesh->corner_verts();
const Span<int> corner_edges = mesh->corner_edges();
int index2 = 0; /* our second vertex index */
LinkNodePair *edgelist = nullptr;
LinkNode *search = nullptr, *search2 = nullptr;
BendSpringRef *spring_ref = nullptr;
/* error handling */
if (numedges == 0) {
return false;
}
/* NOTE: handling ownership of springs and edgeset is quite sloppy
* currently they are never initialized but assert just to be sure */
BLI_assert(cloth->springs == nullptr);
BLI_assert(cloth->edgeset.is_empty());
cloth->springs = nullptr;
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
spring_ref = static_cast<BendSpringRef *>(
MEM_callocN(sizeof(*spring_ref) * numedges, __func__));
if (!spring_ref) {
return false;
}
}
else {
edgelist = static_cast<LinkNodePair *>(MEM_callocN(sizeof(*edgelist) * mvert_num, __func__));
if (!edgelist) {
return false;
}
}
bool use_internal_springs = (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_INTERNAL_SPRINGS);
if (use_internal_springs && numface > 0) {
BVHTreeFromMesh treedata = {nullptr};
int tar_v_idx;
Mesh *tmp_mesh = nullptr;
RNG *rng;
/* If using the rest shape key, it's necessary to make a copy of the mesh. */
if (clmd->sim_parms->shapekey_rest &&
!(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_DYNAMIC_BASEMESH))
{
tmp_mesh = cloth_make_rest_mesh(clmd, mesh);
}
Set<OrderedEdge> existing_vert_pairs;
BKE_bvhtree_from_mesh_get(&treedata, tmp_mesh ? tmp_mesh : mesh, BVHTREE_FROM_LOOPTRI, 2);
rng = BLI_rng_new_srandom(0);
const blender::Span<blender::float3> vert_normals = tmp_mesh ? tmp_mesh->vert_normals() :
mesh->vert_normals();
for (int i = 0; i < mvert_num; i++) {
if (find_internal_spring_target_vertex(
&treedata,
vert_normals,
i,
rng,
clmd->sim_parms->internal_spring_max_length,
clmd->sim_parms->internal_spring_max_diversion,
(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_INTERNAL_SPRINGS_NORMAL),
&tar_v_idx))
{
if (existing_vert_pairs.contains({i, tar_v_idx})) {
/* We have already created a spring between these verts! */
continue;
}
existing_vert_pairs.add({i, tar_v_idx});
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (spring) {
spring_verts_ordered_set(spring, i, tar_v_idx);
shrink_factor = cloth_shrink_factor(clmd, cloth->verts, spring->ij, spring->kl);
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest,
cloth->verts[spring->ij].xrest) *
shrink_factor;
spring->lin_stiffness = (cloth->verts[spring->kl].internal_stiff +
cloth->verts[spring->ij].internal_stiff) /
2.0f;
spring->type = CLOTH_SPRING_TYPE_INTERNAL;
spring->flags = 0;
BLI_linklist_prepend(&cloth->springs, spring);
if (spring_ref) {
spring_ref[i].spring = spring;
}
}
else {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
free_bvhtree_from_mesh(&treedata);
if (tmp_mesh) {
BKE_id_free(nullptr, &tmp_mesh->id);
}
return false;
}
}
}
existing_vert_pairs.clear_and_shrink();
free_bvhtree_from_mesh(&treedata);
if (tmp_mesh) {
BKE_id_free(nullptr, &tmp_mesh->id);
}
BLI_rng_free(rng);
}
clmd->sim_parms->avg_spring_len = 0.0f;
for (int i = 0; i < mvert_num; i++) {
cloth->verts[i].avg_spring_len = 0.0f;
}
if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SEW) {
/* cloth->sew_edge_graph should not exist before this */
BLI_assert(cloth->sew_edge_graph.is_empty());
}
/* Structural springs. */
const LooseEdgeCache &loose_edges = mesh->loose_edges();
for (int i = 0; i < numedges; i++) {
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (spring) {
spring_verts_ordered_set(spring, edges[i][0], edges[i][1]);
if (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SEW && loose_edges.count > 0 &&
loose_edges.is_loose_bits[i])
{
/* handle sewing (loose edges will be pulled together) */
spring->restlen = 0.0f;
spring->lin_stiffness = 1.0f;
spring->type = CLOTH_SPRING_TYPE_SEWING;
cloth->sew_edge_graph.add({edges[i][0], edges[i][1]});
}
else {
shrink_factor = cloth_shrink_factor(clmd, cloth->verts, spring->ij, spring->kl);
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest,
cloth->verts[spring->ij].xrest) *
shrink_factor;
spring->lin_stiffness = (cloth->verts[spring->kl].struct_stiff +
cloth->verts[spring->ij].struct_stiff) /
2.0f;
spring->type = CLOTH_SPRING_TYPE_STRUCTURAL;
clmd->sim_parms->avg_spring_len += spring->restlen;
cloth->verts[spring->ij].avg_spring_len += spring->restlen;
cloth->verts[spring->kl].avg_spring_len += spring->restlen;
cloth->verts[spring->ij].spring_count++;
cloth->verts[spring->kl].spring_count++;
struct_springs_real++;
}
spring->flags = 0;
struct_springs++;
BLI_linklist_prepend(&cloth->springs, spring);
if (spring_ref) {
spring_ref[i].spring = spring;
}
}
else {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
}
if (struct_springs_real > 0) {
clmd->sim_parms->avg_spring_len /= struct_springs_real;
}
for (int i = 0; i < mvert_num; i++) {
if (cloth->verts[i].spring_count > 0) {
cloth->verts[i].avg_spring_len = cloth->verts[i].avg_spring_len * 0.49f /
float(cloth->verts[i].spring_count);
}
}
cloth->edgeset.reserve(numedges);
if (numface) {
for (int i = 0; i < numface; i++) {
/* Shear springs. */
/* Triangle faces already have shear springs due to structural geometry. */
if (faces[i].size() > 3) {
for (int j = 1; j < faces[i].size() - 1; j++) {
if (j > 1) {
if (cloth_add_shear_bend_spring(clmd, edgelist, corner_verts, faces, i, 0, j)) {
shear_springs++;
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
bend_springs++;
}
}
else {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
}
for (int k = j + 2; k < faces[i].size(); k++) {
if (cloth_add_shear_bend_spring(clmd, edgelist, corner_verts, faces, i, j, k)) {
shear_springs++;
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
bend_springs++;
}
}
else {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
}
}
}
/* Angular bending springs along struct springs. */
if (clmd->sim_parms->bending_model == CLOTH_BENDING_ANGULAR) {
for (int j = 0; j < faces[i].size(); j++) {
const int edge_i = corner_edges[faces[i][j]];
BendSpringRef *curr_ref = &spring_ref[edge_i];
curr_ref->face++;
/* First poly found for this edge, store poly index. */
if (curr_ref->face == 1) {
curr_ref->index = i;
}
/* Second poly found for this edge, add bending data. */
else if (curr_ref->face == 2) {
spring = curr_ref->spring;
spring->type |= CLOTH_SPRING_TYPE_BENDING;
spring->la = faces[curr_ref->index].size();
spring->lb = faces[i].size();
if (!cloth_bend_set_poly_vert_array(
&spring->pa, spring->la, &corner_verts[faces[curr_ref->index].start()]) ||
!cloth_bend_set_poly_vert_array(
&spring->pb, spring->lb, &corner_verts[faces[i].start()]))
{
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
spring->mn = edge_i;
spring->restang = cloth_spring_angle(cloth->verts,
spring->ij,
spring->kl,
spring->pa,
spring->pb,
spring->la,
spring->lb);
spring->ang_stiffness = (cloth->verts[spring->ij].bend_stiff +
cloth->verts[spring->kl].bend_stiff) /
2.0f;
bend_springs++;
}
/* Third poly found for this edge, remove bending data. */
else if (curr_ref->face == 3) {
spring = curr_ref->spring;
spring->type &= ~CLOTH_SPRING_TYPE_BENDING;
MEM_freeN(spring->pa);
MEM_freeN(spring->pb);
spring->pa = nullptr;
spring->pb = nullptr;
bend_springs--;
}
}
}
}
/* Linear bending springs. */
if (clmd->sim_parms->bending_model == CLOTH_BENDING_LINEAR) {
search2 = cloth->springs;
for (int i = struct_springs; i < struct_springs + shear_springs; i++) {
if (!search2) {
break;
}
tspring2 = static_cast<ClothSpring *>(search2->link);
search = edgelist[tspring2->kl].list;
while (search) {
tspring = static_cast<ClothSpring *>(search->link);
index2 = ((tspring->ij == tspring2->kl) ? (tspring->kl) : (tspring->ij));
/* Check for existing spring. */
/* Check also if start-point is equal to endpoint. */
if ((index2 != tspring2->ij) && !cloth->edgeset.contains({tspring2->ij, index2})) {
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (!spring) {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
spring_verts_ordered_set(spring, tspring2->ij, index2);
shrink_factor = cloth_shrink_factor(clmd, cloth->verts, spring->ij, spring->kl);
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest,
cloth->verts[spring->ij].xrest) *
shrink_factor;
spring->type = CLOTH_SPRING_TYPE_BENDING;
spring->lin_stiffness = (cloth->verts[spring->kl].bend_stiff +
cloth->verts[spring->ij].bend_stiff) /
2.0f;
cloth->edgeset.add({spring->ij, spring->kl});
bend_springs++;
BLI_linklist_prepend(&cloth->springs, spring);
}
search = search->next;
}
search2 = search2->next;
}
}
}
else if (struct_springs > 2) {
if (G.debug_value != 1112) {
search = cloth->springs;
search2 = search->next;
while (search && search2) {
tspring = static_cast<ClothSpring *>(search->link);
tspring2 = static_cast<ClothSpring *>(search2->link);
if (tspring->ij == tspring2->kl) {
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (!spring) {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
spring->ij = tspring2->ij;
spring->kl = tspring->ij;
spring->mn = tspring->kl;
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest,
cloth->verts[spring->ij].xrest);
spring->type = CLOTH_SPRING_TYPE_BENDING_HAIR;
spring->lin_stiffness = (cloth->verts[spring->kl].bend_stiff +
cloth->verts[spring->ij].bend_stiff) /
2.0f;
bend_springs++;
BLI_linklist_prepend(&cloth->springs, spring);
}
search = search->next;
search2 = search2->next;
}
}
else {
/* bending springs for hair strands
* The current algorithm only goes through the edges in order of the mesh edges list
* and makes springs between the outer vert of edges sharing a vertex. This works just
* fine for hair, but not for user generated string meshes. This could/should be later
* extended to work with non-ordered edges so that it can be used for general "rope
* dynamics" without the need for the vertices or edges to be ordered through the length
* of the strands. -jahka */
search = cloth->springs;
search2 = search->next;
while (search && search2) {
tspring = static_cast<ClothSpring *>(search->link);
tspring2 = static_cast<ClothSpring *>(search2->link);
if (tspring->ij == tspring2->kl) {
spring = (ClothSpring *)MEM_callocN(sizeof(ClothSpring), "cloth spring");
if (!spring) {
cloth_free_errorsprings(cloth, edgelist, spring_ref);
return false;
}
spring->ij = tspring2->ij;
spring->kl = tspring->kl;
spring->restlen = len_v3v3(cloth->verts[spring->kl].xrest,
cloth->verts[spring->ij].xrest);
spring->type = CLOTH_SPRING_TYPE_BENDING;
spring->lin_stiffness = (cloth->verts[spring->kl].bend_stiff +
cloth->verts[spring->ij].bend_stiff) /
2.0f;
bend_springs++;
BLI_linklist_prepend(&cloth->springs, spring);
}
search = search->next;
search2 = search2->next;
}
}
cloth_hair_update_bending_rest_targets(clmd);
}
/* NOTE: the edges may already exist so run reinsert. */
/* Insert other near springs in `edgeset` AFTER bending springs are calculated
* (for self-collision). */
for (int i = 0; i < numedges; i++) { /* struct springs */
cloth->edgeset.add({edges[i][0], edges[i][1]});
}
for (int i = 0; i < numface; i++) { /* edge springs */
if (faces[i].size() == 4) {
cloth->edgeset.add({corner_verts[faces[i].start() + 0], corner_verts[faces[i].start() + 2]});
cloth->edgeset.add({corner_verts[faces[i].start() + 1], corner_verts[faces[i].start() + 3]});
}
}
MEM_SAFE_FREE(spring_ref);
cloth->numsprings = struct_springs + shear_springs + bend_springs;
cloth_free_edgelist(edgelist, mvert_num);
#if 0
if (G.debug_value > 0) {
printf("avg_len: %f\n", clmd->sim_parms->avg_spring_len);
}
#endif
return true;
}
/** \} */