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.

5 files changed, 47 insertions, 4 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);
 	
diff --git a/source/blender/makesdna/DNA_cloth_types.h b/source/blender/makesdna/DNA_cloth_types.h
index fd8b08e68c6..b214186fee6 100644
--- a/source/blender/makesdna/DNA_cloth_types.h
+++ b/source/blender/makesdna/DNA_cloth_types.h
@@ -83,7 +83,7 @@ typedef struct ClothSimSettings
 	short	shapekey_rest;  /* vertex group for scaling structural stiffness */
 	short	presets; /* used for presets on GUI */
 	short 	reset;
-	short	pad;
+	short pad;
 
 	struct EffectorWeights *effector_weights;
 } ClothSimSettings;
@@ -101,6 +101,9 @@ typedef struct ClothCollSettings
 	short	self_loop_count;	/* How many iterations for the selfcollision loop	*/
 	short	loop_count;		/* How many iterations for the collision loop.		*/
 	struct Group *group;	/* Only use colliders from this group of objects */
+	short	vgroup_selfcol; /* vgroup to paint which vertices are used for self collisions */
+	short pad;
+	int pad2;
 } ClothCollSettings;
 
 
diff --git a/source/blender/makesrna/intern/rna_cloth.c b/source/blender/makesrna/intern/rna_cloth.c
index 37795edb884..82a838010f6 100644
--- a/source/blender/makesrna/intern/rna_cloth.c
+++ b/source/blender/makesrna/intern/rna_cloth.c
@@ -155,6 +155,25 @@ static void rna_ClothSettings_bend_vgroup_set(PointerRNA *ptr, const char *value
 	rna_object_vgroup_name_index_set(ptr, value, &sim->vgroup_bend);
 }
 
+
+static void rna_CollSettings_selfcol_vgroup_get(PointerRNA *ptr, char *value)
+{
+	ClothCollSettings *coll = (ClothCollSettings *)ptr->data;
+	rna_object_vgroup_name_index_get(ptr, value, coll->vgroup_selfcol);
+}
+
+static int rna_CollSettings_selfcol_vgroup_length(PointerRNA *ptr)
+{
+	ClothCollSettings *coll = (ClothCollSettings *)ptr->data;
+	return rna_object_vgroup_name_index_length(ptr, coll->vgroup_selfcol);
+}
+
+static void rna_CollSettings_selfcol_vgroup_set(PointerRNA *ptr, const char *value)
+{
+	ClothCollSettings *coll = (ClothCollSettings *)ptr->data;
+	rna_object_vgroup_name_index_set(ptr, value, &coll->vgroup_selfcol);
+}
+
 static PointerRNA rna_ClothSettings_rest_shape_key_get(PointerRNA *ptr)
 {
 	Object *ob = (Object *)ptr->id.data;
@@ -523,6 +542,13 @@ static void rna_def_cloth_collision_settings(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_EDITABLE);
 	RNA_def_property_ui_text(prop, "Collision Group", "Limit colliders to this Group");
 	RNA_def_property_update(prop, 0, "rna_cloth_update");
+
+	prop = RNA_def_property(srna, "vertex_group_self_collisions", PROP_STRING, PROP_NONE);
+	RNA_def_property_string_funcs(prop, "rna_CollSettings_selfcol_vgroup_get", "rna_CollSettings_selfcol_vgroup_length",
+	                              "rna_CollSettings_selfcol_vgroup_set");
+	RNA_def_property_ui_text(prop, "Selfcollision Vertex Group",
+	                         "Vertex group to define vertices which are not used during self collisions.");
+	RNA_def_property_update(prop, 0, "rna_cloth_update");
 }
 
 void RNA_def_cloth(BlenderRNA *brna)