[Bf-blender-cvs] [3a77ea6] hair_immediate_fixes: Partial response force for hair collisions.
Lukas Tönne
noreply at git.blender.org
Mon Sep 1 18:49:23 CEST 2014
Commit: 3a77ea644e7bdf7df5c7ea4b0fa7330df9bcb034
Author: Lukas Tönne
Date: Mon Sep 1 17:46:17 2014 +0200
Branches: hair_immediate_fixes
https://developer.blender.org/rB3a77ea644e7bdf7df5c7ea4b0fa7330df9bcb034
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 8160145..a215b9d 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. @@
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