Added separate damping for bending springs.

The bend damping factor was hardcoded to the same value as the stiffness.
Now it has its own factor in the settings and button in hair dynamics.

5 files changed, 39 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index 297a0e462d0..a77357faee5 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -120,6 +120,7 @@ void cloth_init(ClothModifierData *clmd )
 	clmd->sim_parms->structural = 15.0;
 	clmd->sim_parms->shear = 15.0;
 	clmd->sim_parms->bending = 0.5;
+	clmd->sim_parms->bending_damping = 0.5;
 	clmd->sim_parms->Cdis = 5.0; 
 	clmd->sim_parms->Cvi = 1.0;
 	clmd->sim_parms->mass = 0.3f;
diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index 3ffde3f2583..dcdf51f3dd6 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -491,4 +491,23 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 			}
 		}
 	}
+	
+	if (!DNA_struct_elem_find(fd->filesdna, "ClothSimSettings", "float", "bending_damping")) {
+		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->bending_damping = 0.5f;
+				}
+				else if (md->type == eModifierType_ParticleSystem) {
+					ParticleSystemModifierData *pmd = (ParticleSystemModifierData*) md;
+					if (pmd->psys->clmd) {
+						pmd->psys->clmd->sim_parms->bending_damping = 0.5f;
+					}
+				}
+			}
+		}
+	}
 }
diff --git a/source/blender/makesdna/DNA_cloth_types.h b/source/blender/makesdna/DNA_cloth_types.h
index 39a1abcc76a..85c91a510c0 100644
--- a/source/blender/makesdna/DNA_cloth_types.h
+++ b/source/blender/makesdna/DNA_cloth_types.h
@@ -76,6 +76,10 @@ typedef struct ClothSimSettings {
 	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) */
 	
+	/* XXX various hair stuff
+	 * should really be separate, this struct is a horrible mess already
+	 */
+	float	bending_damping;	/* damping of bending springs */
 	int		voxel_res;          /* resolution of voxel grid for interaction */
 	int		voxel_filter_size;  /* filter size for voxel grid */
 
@@ -91,7 +95,6 @@ typedef struct ClothSimSettings {
 	short	shapekey_rest;  /* vertex group for scaling structural stiffness */
 	short	presets; /* used for presets on GUI */
 	short 	reset;
-	int		pad;
 
 	struct EffectorWeights *effector_weights;
 } ClothSimSettings;
diff --git a/source/blender/makesrna/intern/rna_cloth.c b/source/blender/makesrna/intern/rna_cloth.c
index 57dc3ea293d..4e1c91269a3 100644
--- a/source/blender/makesrna/intern/rna_cloth.c
+++ b/source/blender/makesrna/intern/rna_cloth.c
@@ -544,6 +544,13 @@ static void rna_def_cloth_sim_settings(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Bending Stiffness Maximum", "Maximum bending stiffness value");
 	RNA_def_property_update(prop, 0, "rna_cloth_update");
 
+	prop = RNA_def_property(srna, "bending_damping", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "bending_damping");
+	RNA_def_property_range(prop, 0.0f, 1000.0f);
+	RNA_def_property_ui_text(prop, "Bending Spring Damping",
+	                         "Damping of bending motion");
+	RNA_def_property_update(prop, 0, "rna_cloth_update");
+
 	prop = RNA_def_property(srna, "use_sewing_springs", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flags", CLOTH_SIMSETTINGS_FLAG_SEW);
 	RNA_def_property_ui_text(prop, "Sew Cloth", "Pulls loose edges together");
diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp b/source/blender/physics/intern/BPH_mass_spring.cpp
index 0138178b722..6a768f10d11 100644
--- a/source/blender/physics/intern/BPH_mass_spring.cpp
+++ b/source/blender/physics/intern/BPH_mass_spring.cpp
@@ -410,7 +410,10 @@ BLI_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s,
 		s->flags |= CLOTH_SPRING_FLAG_NEEDED;
 		
 		scaling = parms->bending + s->stiffness * fabsf(parms->max_bend - parms->bending);
-		cb = kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
+		kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
+		
+		scaling = parms->bending_damping;
+		cb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
 		
 		BPH_mass_spring_force_spring_bending(data, s->ij, s->kl, s->matrix_ij_kl, s->restlen, kb, cb, s->f, s->dfdx, s->dfdv);
 #endif
@@ -422,7 +425,10 @@ BLI_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s,
 		s->flags |= CLOTH_SPRING_FLAG_NEEDED;
 		
 		scaling = parms->bending + s->stiffness * fabsf(parms->max_bend - parms->bending);
-		cb = kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
+		kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
+		
+		scaling = parms->bending_damping;
+		cb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
 		
 		/* XXX assuming same restlen for ij and jk segments here, this can be done correctly for hair later */
 		BPH_mass_spring_force_spring_bending_angular(data, s->ij, s->kl, s->mn, s->matrix_ij_kl, s->matrix_kl_mn, s->matrix_ij_mn, s->target, kb, cb);