[Bf-blender-cvs] [48e67c4] master: Added separate damping for bending springs.

[Lukas Tönne]

Commit: 48e67c49a5951d20643533958dc28705cfe476e9
Author: Lukas Tönne
Date:   Fri Sep 26 17:25:21 2014 +0200
Branches: master
https://developer.blender.org/rB48e67c49a5951d20643533958dc28705cfe476e9

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.

===================================================================

M	release/scripts/startup/bl_ui/properties_particle.py
M	source/blender/blenkernel/intern/cloth.c
M	source/blender/blenloader/intern/versioning_270.c
M	source/blender/makesdna/DNA_cloth_types.h
M	source/blender/makesrna/intern/rna_cloth.c
M	source/blender/physics/intern/BPH_mass_spring.cpp

===================================================================

diff --git a/release/scripts/startup/bl_ui/properties_particle.py b/release/scripts/startup/bl_ui/properties_particle.py
index d725738..d9b66a6 100644
--- a/release/scripts/startup/bl_ui/properties_particle.py
+++ b/release/scripts/startup/bl_ui/properties_particle.py
@@ -330,6 +330,7 @@ class PARTICLE_PT_hair_dynamics(ParticleButtonsPanel, Panel):
         sub = col.column(align=True)
         sub.prop(cloth, "spring_damping", text="Spring")
         sub.prop(cloth, "air_damping", text="Air")
+        sub.prop(cloth, "bending_damping", text="Bending")
 
         col.label(text="Quality:")
         col.prop(cloth, "quality", text="Steps", slider=True)
diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index 297a0e4..a77357f 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 3ffde3f..dcdf51f 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 39a1abc..85c91a5 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 57dc3ea..4e1c912 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 0138178..6a768f1 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);