Cloth: Add support for "Self Collision Vertex Group".

Self collision vertex groups enable artists to exclude selected vertices from getting involved in self collisions. This speeds simulations and it also resolves some self collision issues.

3 files changed, 17 insertions, 3 deletions

diff --git a/source/blender/blenkernel/BKE_cloth.h b/source/blender/blenkernel/BKE_cloth.h
index 378cc72beb1..3475ef532da 100644
--- a/source/blender/blenkernel/BKE_cloth.h
+++ b/source/blender/blenkernel/BKE_cloth.h
@@ -56,7 +56,7 @@ struct CollisionTree;
 
 /* Bits to or into the ClothVertex.flags. */
 #define CLOTH_VERT_FLAG_PINNED 1
-#define CLOTH_VERT_FLAG_COLLISION 2
+#define CLOTH_VERT_FLAG_NOSELFCOLL 2 /* vertex NOT used for self collisions */
 #define CLOTH_VERT_FLAG_PINNED_EM 3
 
 /**
diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index e067b7195ce..b681426f8a7 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -143,6 +143,7 @@ void cloth_init(ClothModifierData *clmd )
 	clmd->coll_parms->collision_list = NULL;
 	clmd->coll_parms->self_loop_count = 1.0;
 	clmd->coll_parms->selfepsilon = 0.75;
+	clmd->coll_parms->vgroup_selfcol = 0;
 
 	/* These defaults are copied from softbody.c's
 	 * softbody_calc_forces() function.
@@ -756,10 +757,12 @@ static void cloth_to_object (Object *ob,  ClothModifierData *clmd, float (*verte
 int cloth_uses_vgroup(ClothModifierData *clmd)
 {
 	return (((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SCALING ) || 
-		(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL )) && 
+		(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL ) ||
+		(clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_SELF)) && 
 		((clmd->sim_parms->vgroup_mass>0) || 
 		(clmd->sim_parms->vgroup_struct>0)||
-		(clmd->sim_parms->vgroup_bend>0)));
+		(clmd->sim_parms->vgroup_bend>0)  ||
+		(clmd->coll_parms->vgroup_selfcol>0)));
 }
 
 /**
@@ -815,6 +818,13 @@ static void cloth_apply_vgroup ( ClothModifierData *clmd, DerivedMesh *dm )
 							verts->bend_stiff = dvert->dw [j].weight;
 						}
 					}
+
+					if (clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_SELF ) {
+						if ( dvert->dw[j].def_nr == (clmd->coll_parms->vgroup_selfcol-1)) {
+							if( dvert->dw [j].weight > 0.0)
+								verts->flags |= CLOTH_VERT_FLAG_NOSELFCOLL;
+						}
+					}
 					/*
 					// for later
 					if ( dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_weight-1))
diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c
index 32e9dd7508b..44f524304d2 100644
--- a/source/blender/blenkernel/intern/collision.c
+++ b/source/blender/blenkernel/intern/collision.c
@@ -840,6 +840,10 @@ int cloth_bvh_objcollision(Object *ob, ClothModifierData * clmd, float step, flo
 								continue;
 							}
 						}
+
+						if( ( cloth->verts[i].flags & CLOTH_VERT_FLAG_NOSELFCOLL ) || 
+							( cloth->verts[j].flags & CLOTH_VERT_FLAG_NOSELFCOLL ) )
+							continue;
 	
 						sub_v3_v3v3(temp, verts[i].tx, verts[j].tx);