Commit: 1ed88bb24e13f7d911de708e5b2479a937734183 Author: Lukas Tönne Date: Mon Sep 1 17:46:17 2014 +0200 Branches: master https://developer.blender.org/rB1ed88bb24e13f7d911de708e5b2479a937734183
Partial response force for hair collisions. This implements a penalty force as well as a repulsion force to avoid further penetration, as suggested in "Simulating Complex Hair with Robust Collision Handling" (http://graphics.snu.ac.kr/publications/2005-choe-HairSim/Choe_2005_SCA.pdf) Friction forces are still missing. More problematic is handling of moving colliders, when face swap places with the hair vertex and a collision is missed, putting the vertex inside the mesh volume. Larger margins might help, but ultimately using Bullet collision detection is probably more reliable and failsafe. =================================================================== M source/blender/blenkernel/BKE_effect.h M source/blender/blenkernel/intern/collision.c M source/blender/blenkernel/intern/effect.c M source/blender/blenloader/intern/readfile.c M source/blender/makesdna/DNA_cloth_types.h M source/blender/makesrna/intern/rna_cloth.c =================================================================== diff --git a/source/blender/blenkernel/BKE_effect.h b/source/blender/blenkernel/BKE_effect.h index d6991a4..852f9de 100644 --- a/source/blender/blenkernel/BKE_effect.h +++ b/source/blender/blenkernel/BKE_effect.h @@ -160,6 +160,7 @@ struct SimDebugData *BKE_sim_debug_data_new(void); void BKE_sim_debug_data_add_dot(struct SimDebugData *debug_data, const float p[3], float r, float g, float b, int hash); void BKE_sim_debug_data_add_line(struct SimDebugData *debug_data, const float p1[3], const float p2[3], float r, float g, float b, int hash); void BKE_sim_debug_data_add_vector(struct SimDebugData *debug_data, const float p[3], const float d[3], float r, float g, float b, int hash); +void BKE_sim_debug_data_remove(struct SimDebugData *debug_data, int hash); void BKE_sim_debug_data_clear(struct SimDebugData *debug_data); void BKE_sim_debug_data_free(struct SimDebugData *debug_data); diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c index b38609e..94e2c55 100644 --- a/source/blender/blenkernel/intern/collision.c +++ b/source/blender/blenkernel/intern/collision.c @@ -33,6 +33,7 @@ #include "MEM_guardedalloc.h" #include "DNA_cloth_types.h" +#include "DNA_effect_types.h" #include "DNA_group_types.h" #include "DNA_object_types.h" #include "DNA_object_force.h" @@ -45,6 +46,7 @@ #include "BLI_edgehash.h" #include "BKE_cloth.h" +#include "BKE_effect.h" #include "BKE_modifier.h" #include "BKE_scene.h" @@ -59,6 +61,41 @@ #endif +/* ==== hash functions for debugging ==== */ +static unsigned int hash_int_2d(unsigned int kx, unsigned int ky) +{ +#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) + + unsigned int a, b, c; + + a = b = c = 0xdeadbeef + (2 << 2) + 13; + a += kx; + b += ky; + + c ^= b; c -= rot(b,14); + a ^= c; a -= rot(c,11); + b ^= a; b -= rot(a,25); + c ^= b; c -= rot(b,16); + a ^= c; a -= rot(c,4); + b ^= a; b -= rot(a,14); + c ^= b; c -= rot(b,24); + + return c; + +#undef rot +} + +static int hash_vertex(int type, int vertex) +{ + return hash_int_2d((unsigned int)type, (unsigned int)vertex); +} + +static int hash_collpair(int type, CollPair *collpair) +{ + return hash_int_2d((unsigned int)type, hash_int_2d((unsigned int)collpair->face1, (unsigned int)collpair->face2)); +} +/* ================ */ + /*********************************** Collision modifier code start ***********************************/ @@ -914,24 +951,35 @@ int cloth_bvh_objcollision(Object *ob, ClothModifierData *clmd, float step, floa return 1|MIN2 ( ret, 1 ); } +BLI_INLINE void max_v3_v3v3(float r[3], const float a[3], const float b[3]) +{ + r[0] = max_ff(a[0], b[0]); + r[1] = max_ff(a[1], b[1]); + r[2] = max_ff(a[2], b[2]); +} -static int cloth_points_collision_response_static(ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end) +static bool cloth_points_collision_response_static(ClothModifierData *clmd, CollisionModifierData *collmd, PartDeflect *pd, + CollPair *collpair, CollPair *collision_end, float dt) { - int result = 0; - Cloth *cloth1; + bool result = false; + float restitution = (1.0f - clmd->coll_parms->damping) * (1.0f - pd->pdef_sbdamp); + float inv_dt = 1.0f / dt; + Cloth *cloth1 = clmd->clothObject; + float w1, w2, u1, u2, u3; - float v1[3], v2[3], relativeVelocity[3]; - float magrelVel; + float v1[3], v2_old[3], v2_new[3], v_rel_old[3], v_rel_new[3]; +// float magrelVel; float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree ); - cloth1 = clmd->clothObject; - for ( ; collpair != collision_end; collpair++ ) { -// float i1[3], i2[3], i3[3]; + float margin_distance = collpair->distance - epsilon2; + float impulse[3]; + float mag_v_rel; -// zero_v3(i1); -// zero_v3(i2); -// zero_v3(i3); + if (margin_distance > 0.0f) + continue; + + zero_v3(impulse); /* only handle static collisions here */ if ( collpair->flag & COLLISION_IN_FUTURE ) @@ -951,17 +999,75 @@ static int cloth_points_collision_response_static(ClothModifierData *clmd, Colli /* Calculate relative velocity */ copy_v3_v3(v1, cloth1->verts[collpair->ap1].tv); - collision_interpolateOnTriangle ( v2, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, u1, u2, u3 ); + collision_interpolateOnTriangle ( v2_new, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, u1, u2, u3 ); + /* XXX assume constant velocity of the collider for now */ + copy_v3_v3(v2_old, v2_new); - sub_v3_v3v3(relativeVelocity, v2, v1); + sub_v3_v3v3(v_rel_old, v1, v2_old); + sub_v3_v3v3(v_rel_new, v1, v2_new); - /* Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal'). */ - magrelVel = dot_v3v3(relativeVelocity, collpair->normal); + /* normal component of the relative velocity */ + mag_v_rel = dot_v3v3(v_rel_old, collpair->normal); - /* printf("magrelVel: %f\n", magrelVel); */ + /**** DEBUG ****/ + if (clmd->debug_data) { + BKE_sim_debug_data_add_dot(clmd->debug_data, collpair->pa, 0.9, 0.2, 0.2, hash_collpair(833, collpair)); + BKE_sim_debug_data_add_dot(clmd->debug_data, collpair->pb, 0.2, 0.9, 0.2, hash_collpair(834, collpair)); + BKE_sim_debug_data_add_line(clmd->debug_data, collpair->pa, collpair->pb, 0.8, 0.8, 0.8, hash_collpair(835, collpair)); + BKE_sim_debug_data_add_vector(clmd->debug_data, collpair->pa, collpair->normal, 1.0, 1.0, 0.0, hash_collpair(836, collpair)); + } + /********/ - /* Calculate masses of points. - * TODO */ + if (mag_v_rel < -ALMOST_ZERO) { + float v_nor_old, v_nor_new; + float v_tan_old[3], v_tan_new[3]; + float repulse[3]; + + /* 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); + + mul_v3_v3fl(repulse, collpair->normal, -margin_distance * inv_dt); + sub_v3_v3(repulse, v1); + +// if (margin_distance < -epsilon2) { + { + float bounce[3]; + + mul_v3_v3fl(bounce, collpair->normal, -(v_nor_new + v_nor_old * restitution)); +// max_v3_v3v3(impulse, repulse, bounce); + copy_v3_v3(impulse, bounce); + } +// else { +// copy_v3_v3(impulse, repulse); +// } + cloth1->verts[collpair->ap1].impulse_count++; + BKE_sim_debug_data_add_vector(clmd->debug_data, collpair->pa, impulse, 0.0, 1.0, 0.6, hash_collpair(873, collpair)); + + result = true; + } + else { + BKE_sim_debug_data_remove(clmd->debug_data, hash_collpair(833, collpair)); + BKE_sim_debug_data_remove(clmd->debug_data, hash_collpair(834, collpair)); + BKE_sim_debug_data_remove(clmd->debug_data, hash_collpair(835, collpair)); + BKE_sim_debug_data_remove(clmd->debug_data, hash_collpair(873, collpair)); + } + + if (result) { + int i = 0; + + for (i = 0; i < 3; i++) { + if (cloth1->verts[collpair->ap1].impulse_count > 0 && fabsf(cloth1->verts[collpair->ap1].impulse[i]) < fabsf(impulse[i])) + cloth1->verts[collpair->ap1].impulse[i] = impulse[i]; + } + } #if 0 /* If v_n_mag < 0 the edges are approaching each other. */ @@ -1163,7 +1269,8 @@ static void cloth_points_objcollisions_nearcheck(ClothModifierData * clmd, Colli } } -static int cloth_points_objcollisions_resolve ( ClothModifierData * clmd, CollisionModifierData *collmd, CollPair *collisions, CollPair *collisions_index) +static int cloth_points_objcollisions_resolve(ClothModifierData * clmd, CollisionModifierData *collmd, PartDeflect *pd, + CollPair *collisions, CollPair *collisions_index, float dt) { Cloth *cloth = clmd->clothObject; int i=0, numverts = clmd->clothObject->numverts; @@ -1172,7 +1279,7 @@ static int cloth_points_objcollisions_resolve ( ClothModifierData * clmd, Collis // process all collisions if ( collmd->bvhtree ) { - int result = cloth_points_collision_response_static(clmd, collmd, collisions, collisions_index); + bool result = cloth_points_collision_response_static(clmd, collmd, pd, collisions, collisions_index, dt); // apply impulses in parallel if (result) { @@ -1189,36 +1296,6 @@ static int cloth_points_objcollisions_resolve ( ClothModifierData * clmd, Collis } } } -#if 0 - // process all collisions (calculate impulses, TODO: also repulses if distance too short) - result = 1; - for ( j = 0; j < 2; j++ ) { /* 5 is just a value that ensures convergence */ - result = 0; - - if ( collmd->bvhtree ) { - result += cloth_points_collision_response_static(clmd, collmd, collisions, collisions_index); - - // apply impulses in parallel - if (result) { - for (i = 0; i < numverts; i++) { - // calculate "velocities" (just xnew = xold + v; no dt in v) - if (verts[i].impulse_count) { - // VECADDMUL ( verts[i].tv, verts[i].impulse, 1.0f / verts[i].impulse_count ); - VECADD ( verts[i].tv, verts[i].tv, verts[i].impulse); - zero_v3(verts[i].impulse); - verts[i].impulse_count = 0; - - ret++; - } - } - } - } - - if (!result) { - break; - } - } -#endif return ret; } @@ -1244,7 +1321,7 @@ int cloth_points_objcollision(Object *ob, ClothModifierData *clmd, float step, f //////////////////////////////////////////////////////////// // create temporary cloth points bvh - cloth_bvh = BLI_bvhtree_new(numverts, MAX2(clmd->coll_parms->epsilon, clmd->coll_parms->distance_repel), 2, 26); + cloth_bvh = BLI_bvhtree_new(numverts, MAX2(clmd->coll_parms->epsilon, clmd->coll_parms->distance_repel), 4, 6); /* fill tree */ for (i = 0; i < numverts; i++) { float co[6]; @@ -1300,7 +1377,7 @@ int cloth_points_objcollision(Object *ob, ClothModifierData *clmd, float step, f result, overlap, round_dt); // res @@ Diff output truncated at 10240 characters. @@ _______________________________________________ Bf-blender-cvs mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-blender-cvs
