7 files changed, 32 insertions, 8 deletions
diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index 9fb42d5e989..4132fc86608 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -132,6 +132,8 @@ void cloth_init(ClothModifierData *clmd )
 	clmd->sim_parms->goalfrict = 0.0f;
 	clmd->sim_parms->velocity_smooth = 0.0f;
 
+	clmd->sim_parms->voxel_res = 32;
+
 	if (!clmd->sim_parms->effector_weights)
 		clmd->sim_parms->effector_weights = BKE_add_effector_weights(NULL);
 
diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index bde3f0f2512..3ffde3f2583 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -472,4 +472,23 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 			}
 		}
 	}
+
+	if (!DNA_struct_elem_find(fd->filesdna, "ClothSimSettings", "int", "voxel_res")) {
+		Object *ob;
+		ModifierData *md;
+		for (ob = main->object.first; ob; ob = ob->id.next) {
+			for (md = ob->modifiers.first; md; md = md->next) {
+				if (md->type == eModifierType_Cloth) {
+					ClothModifierData *clmd = (ClothModifierData*) md;
+					clmd->sim_parms->voxel_res = 32;
+				}
+				else if (md->type == eModifierType_ParticleSystem) {
+					ParticleSystemModifierData *pmd = (ParticleSystemModifierData*) md;
+					if (pmd->psys->clmd) {
+						pmd->psys->clmd->sim_parms->voxel_res = 32;
+					}
+				}
+			}
+		}
+	}
 }
diff --git a/source/blender/makesdna/DNA_cloth_types.h b/source/blender/makesdna/DNA_cloth_types.h
index 4d862e48109..c7eee96bd06 100644
--- a/source/blender/makesdna/DNA_cloth_types.h
+++ b/source/blender/makesdna/DNA_cloth_types.h
@@ -75,6 +75,7 @@ typedef struct ClothSimSettings {
 	float	vel_damping; /* damp the velocity to speed up getting to the resting position */
 	float	shrink_min;  /* min amount to shrink cloth by 0.0f (no shrink) - 1.0f (shrink to nothing) */
 	float	shrink_max;  /* max amount to shrink cloth by 0.0f (no shrink) - 1.0f (shrink to nothing) */
+	int		voxel_res;   /* resolution of voxel grid for interaction */
 
 	int 	stepsPerFrame;	/* Number of time steps per frame.		*/
 	int	flags;		/* flags, see CSIMSETT_FLAGS enum above.	*/
@@ -88,7 +89,6 @@ typedef struct ClothSimSettings {
 	short	shapekey_rest;  /* vertex group for scaling structural stiffness */
 	short	presets; /* used for presets on GUI */
 	short 	reset;
-	char    pad[4];
 
 	struct EffectorWeights *effector_weights;
 } ClothSimSettings;
diff --git a/source/blender/makesrna/intern/rna_cloth.c b/source/blender/makesrna/intern/rna_cloth.c
index 5d911dd3ddf..8528a664458 100644
--- a/source/blender/makesrna/intern/rna_cloth.c
+++ b/source/blender/makesrna/intern/rna_cloth.c
@@ -410,6 +410,13 @@ static void rna_def_cloth_sim_settings(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Shrink Factor Max", "Max amount to shrink cloth by");
 	RNA_def_property_update(prop, 0, "rna_cloth_update");
 
+	prop = RNA_def_property(srna, "voxel_resolution", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "voxel_res");
+	RNA_def_property_range(prop, 1, 128);
+	RNA_def_property_int_default(prop, 32);
+	RNA_def_property_ui_text(prop, "Voxel Grid Resolution", "Resolution of the voxel grid for interaction effects");
+	RNA_def_property_update(prop, 0, "rna_cloth_update");
+
 	/* springs */
 
 	prop = RNA_def_property(srna, "use_stiffness_scale", PROP_BOOLEAN, PROP_NONE);
diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp b/source/blender/physics/intern/BPH_mass_spring.cpp
index e9107394bd2..0fa14fa4eab 100644
--- a/source/blender/physics/intern/BPH_mass_spring.cpp
+++ b/source/blender/physics/intern/BPH_mass_spring.cpp
@@ -421,7 +421,7 @@ static void cloth_calc_volume_force(ClothModifierData *clmd)
 	
 	/* gather velocities & density */
 	if (smoothfac > 0.0f || pressfac > 0.0f) {
-		HairVertexGrid *vertex_grid = BPH_hair_volume_create_vertex_grid(gmin, gmax);
+		HairVertexGrid *vertex_grid = BPH_hair_volume_create_vertex_grid(clmd->sim_parms->voxel_res, gmin, gmax);
 		
 		for (i = 0; i < numverts; i++) {
 			float x[3], v[3];
diff --git a/source/blender/physics/intern/hair_volume.c b/source/blender/physics/intern/hair_volume.c
index c129f029873..2d5efa8260b 100644
--- a/source/blender/physics/intern/hair_volume.c
+++ b/source/blender/physics/intern/hair_volume.c
@@ -57,9 +57,6 @@
 
 static float I[3][3] = {{1, 0, 0}, {0, 1, 0}, {0, 0, 1}};
 
-/* 10x10x10 grid gives nice initial results */
-static const int hair_grid_res = 10;
-
 static int hair_grid_size(int res)
 {
 	return res * res * res;
@@ -296,9 +293,8 @@ void BPH_hair_volume_normalize_vertex_grid(HairVertexGrid *grid)
 	}
 }
 
-HairVertexGrid *BPH_hair_volume_create_vertex_grid(const float gmin[3], const float gmax[3])
+HairVertexGrid *BPH_hair_volume_create_vertex_grid(int res, const float gmin[3], const float gmax[3])
 {
-	int res = hair_grid_res;
 	int size = hair_grid_size(res);
 	HairVertexGrid *grid;
 	int	            i = 0;
diff --git a/source/blender/physics/intern/implicit.h b/source/blender/physics/intern/implicit.h
index 66ee92f950e..28c4cbcf7ae 100644
--- a/source/blender/physics/intern/implicit.h
+++ b/source/blender/physics/intern/implicit.h
@@ -150,7 +150,7 @@ bool BPH_mass_spring_force_spring_goal(struct Implicit_Data *data, int i, int sp
 struct HairVertexGrid;
 struct HairColliderGrid;
 
-struct HairVertexGrid *BPH_hair_volume_create_vertex_grid(const float gmin[3], const float gmax[3]);
+struct HairVertexGrid *BPH_hair_volume_create_vertex_grid(int res, const float gmin[3], const float gmax[3]);
 void BPH_hair_volume_free_vertex_grid(struct HairVertexGrid *grid);
 
 void BPH_hair_volume_add_vertex(struct HairVertexGrid *grid, const float x[3], const float v[3]);