[Bf-blender-cvs] [d4a46809d0] cloth-improvements: Implement single sided collisions
Luca Rood
noreply at git.blender.org
Tue Jan 17 02:32:58 CET 2017
Commit: d4a46809d05402fbef8639d10cede39fe0a724f8
Author: Luca Rood
Date: Mon Jan 16 23:31:22 2017 -0200
Branches: cloth-improvements
https://developer.blender.org/rBd4a46809d05402fbef8639d10cede39fe0a724f8
Implement single sided collisions
===================================================================
M release/scripts/startup/bl_ui/properties_physics_cloth.py
M source/blender/blenkernel/BKE_cloth.h
M source/blender/blenkernel/intern/collision.c
M source/blender/makesrna/intern/rna_cloth.c
===================================================================
diff --git a/release/scripts/startup/bl_ui/properties_physics_cloth.py b/release/scripts/startup/bl_ui/properties_physics_cloth.py
index d7396d7889..f5f5ce36d7 100644
--- a/release/scripts/startup/bl_ui/properties_physics_cloth.py
+++ b/release/scripts/startup/bl_ui/properties_physics_cloth.py
@@ -243,9 +243,11 @@ class PHYSICS_PT_cloth_collision(PhysicButtonsPanel, Panel):
col.prop(cloth, "distance_min", slider=True, text="Distance")
col.prop(cloth, "distance_repel", slider=True, text="Repel Distance")
- sub = layout.column()
- sub.active = cloth.use_collision
- sub.prop(cloth, "group")
+ col = layout.column()
+ col.active = cloth.use_collision
+ col.prop(cloth, "group")
+
+ col.prop(cloth, "use_normal")
layout.separator()
diff --git a/source/blender/blenkernel/BKE_cloth.h b/source/blender/blenkernel/BKE_cloth.h
index c505e5fcbd..9e2b98a7ae 100644
--- a/source/blender/blenkernel/BKE_cloth.h
+++ b/source/blender/blenkernel/BKE_cloth.h
@@ -180,6 +180,7 @@ typedef enum {
typedef enum {
CLOTH_COLLSETTINGS_FLAG_ENABLED = ( 1 << 1 ), /* enables cloth - object collisions */
CLOTH_COLLSETTINGS_FLAG_SELF = ( 1 << 2 ), /* enables selfcollisions */
+ CLOTH_COLLSETTINGS_FLAG_USE_NORMAL = ( 1 << 3 ), /* enable collision side detection based on normal */
} CLOTH_COLLISIONSETTINGS_FLAGS;
/* Spring types as defined in the paper.*/
diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c
index b79f69d413..46d82784e4 100644
--- a/source/blender/blenkernel/intern/collision.c
+++ b/source/blender/blenkernel/intern/collision.c
@@ -234,6 +234,8 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
float v1[3], v2[3], relativeVelocity[3];
float magrelVel;
float epsilon2 = BLI_bvhtree_get_epsilon ( collmd->bvhtree );
+ float collider_norm[3];
+ bool backside;
cloth1 = clmd->clothObject;
@@ -262,6 +264,16 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
collmd->current_x[collpair->bp3].co,
&u1, &u2, &u3 );
+ /* compute collision normal */
+ if (clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_USE_NORMAL) {
+ normal_tri_v3(collider_norm, collmd->current_x[collpair->bp1].co, collmd->current_x[collpair->bp2].co, collmd->current_x[collpair->bp3].co);
+ backside = dot_v3v3(collider_norm, collpair->normal) < 0.0f;
+ }
+ else {
+ copy_v3_v3(collider_norm, collpair->normal);
+ backside = false;
+ }
+
/* Calculate relative "velocity". */
collision_interpolateOnTriangle ( v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, cloth1->verts[collpair->ap3].tv, w1, w2, w3 );
@@ -270,7 +282,7 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
sub_v3_v3v3(relativeVelocity, v2, v1);
/* Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal'). */
- magrelVel = dot_v3v3(relativeVelocity, collpair->normal);
+ magrelVel = dot_v3v3(relativeVelocity, collider_norm);
/* printf("magrelVel: %f\n", magrelVel); */
@@ -286,7 +298,7 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
float temp[3], spf;
/* calculate tangential velocity */
- copy_v3_v3 ( temp, collpair->normal );
+ copy_v3_v3 ( temp, collider_norm );
mul_v3_fl(temp, magrelVel);
sub_v3_v3v3(vrel_t_pre, relativeVelocity, temp);
@@ -316,14 +328,38 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
/* Impulse shoud be uniform throughout polygon, the scaling used above was wrong */
impulse = magrelVel / 1.5f;
- VECADDMUL ( i1, collpair->normal, w1 * impulse );
- cloth1->verts[collpair->ap1].impulse_count++;
+ if (backside) {
+ float pt_relvel[3];
+ float pt_magvel;
+
+ sub_v3_v3v3(pt_relvel, collmd->current_v[collpair->bp1].co, cloth1->verts[collpair->ap1].tv);
+ pt_magvel = dot_v3v3(pt_relvel, collider_norm);
+
+ VECADDMUL ( i1, collider_norm, pt_magvel * 0.25f );
+ cloth1->verts[collpair->ap1].impulse_count++;
+
+ sub_v3_v3v3(pt_relvel, collmd->current_v[collpair->bp2].co, cloth1->verts[collpair->ap2].tv);
+ pt_magvel = dot_v3v3(pt_relvel, collider_norm);
+
+ VECADDMUL ( i2, collider_norm, pt_magvel * 0.25f );
+ cloth1->verts[collpair->ap2].impulse_count++;
+
+ sub_v3_v3v3(pt_relvel, collmd->current_v[collpair->bp3].co, cloth1->verts[collpair->ap3].tv);
+ pt_magvel = dot_v3v3(pt_relvel, collider_norm);
+
+ VECADDMUL ( i3, collider_norm, pt_magvel * 0.25f );
+ cloth1->verts[collpair->ap3].impulse_count++;
+ }
+ else {
+ VECADDMUL ( i1, collider_norm, w1 * impulse );
+ cloth1->verts[collpair->ap1].impulse_count++;
- VECADDMUL ( i2, collpair->normal, w2 * impulse );
- cloth1->verts[collpair->ap2].impulse_count++;
+ VECADDMUL ( i2, collider_norm, w2 * impulse );
+ cloth1->verts[collpair->ap2].impulse_count++;
- VECADDMUL ( i3, collpair->normal, w3 * impulse );
- cloth1->verts[collpair->ap3].impulse_count++;
+ VECADDMUL ( i3, collider_norm, w3 * impulse );
+ cloth1->verts[collpair->ap3].impulse_count++;
+ }
/* Apply repulse impulse if distance too short
* I_r = -min(dt*kd, m(0, 1d/dt - v_n))
@@ -333,7 +369,13 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
* DG TODO: Fix usage of dt here! */
spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
- d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f - collpair->distance;
+ if (backside) {
+ d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f;
+ }
+ else {
+ d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f - collpair->distance;
+ }
+
if ( ( magrelVel < 0.1f*d*spf ) && ( d > ALMOST_ZERO ) ) {
repulse = MIN2 ( d*1.0f/spf, 0.1f*d*spf - magrelVel );
@@ -347,9 +389,9 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
/* Impulse shoud be uniform throughout polygon, the scaling used above was wrong */
impulse = repulse / 1.5f;
- VECADDMUL ( i1, collpair->normal, impulse );
- VECADDMUL ( i2, collpair->normal, impulse );
- VECADDMUL ( i3, collpair->normal, impulse );
+ VECADDMUL ( i1, collider_norm, impulse );
+ VECADDMUL ( i2, collider_norm, impulse );
+ VECADDMUL ( i3, collider_norm, impulse );
}
result = 1;
@@ -361,8 +403,15 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
* v += impulse; x_new = x + v;
* We don't use dt!! */
float spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
+ float d;
+
+ if (backside) {
+ d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f;
+ }
+ else {
+ d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f - (float)collpair->distance;
+ }
- float d = clmd->coll_parms->epsilon*8.0f/9.0f + epsilon2*8.0f/9.0f - (float)collpair->distance;
if ( d > ALMOST_ZERO) {
/* stay on the safe side and clamp repulse */
float repulse = d*1.0f/spf;
@@ -372,9 +421,9 @@ static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionM
/* Impulse shoud be uniform throughout polygon, the scaling used above was wrong */
float impulse = repulse / 4.5f;
- VECADDMUL ( i1, collpair->normal, impulse );
- VECADDMUL ( i2, collpair->normal, impulse );
- VECADDMUL ( i3, collpair->normal, impulse );
+ VECADDMUL ( i1, collider_norm, impulse );
+ VECADDMUL ( i2, collider_norm, impulse );
+ VECADDMUL ( i3, collider_norm, impulse );
cloth1->verts[collpair->ap1].impulse_count++;
cloth1->verts[collpair->ap2].impulse_count++;
diff --git a/source/blender/makesrna/intern/rna_cloth.c b/source/blender/makesrna/intern/rna_cloth.c
index 13de955d52..095d90b182 100644
--- a/source/blender/makesrna/intern/rna_cloth.c
+++ b/source/blender/makesrna/intern/rna_cloth.c
@@ -842,6 +842,11 @@ static void rna_def_cloth_collision_settings(BlenderRNA *brna)
"How many collision iterations should be done. (higher is better quality but slower)");
RNA_def_property_update(prop, 0, "rna_cloth_update");
+ prop = RNA_def_property(srna, "use_normal", PROP_BOOLEAN, PROP_NONE);
+ RNA_def_property_boolean_sdna(prop, NULL, "flags", CLOTH_COLLSETTINGS_FLAG_USE_NORMAL);
+ RNA_def_property_ui_text(prop, "Single Sided", "Collision acts with respect to the collider normals (improves penetration recovery)");
+ RNA_def_property_update(prop, 0, "rna_cloth_update");
+
/* self collision */
prop = RNA_def_property(srna, "use_self_collision", PROP_BOOLEAN, PROP_NONE);
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