[Bf-blender-cvs] [af8c0c8] gooseberry: Fix for applying the bending randomness factor.

[Lukas Tönne]

Commit: af8c0c84f600a8c735fc8e4d514b404c962b5b03
Author: Lukas Tönne
Date:   Tue Nov 18 10:30:11 2014 +0100
Branches: gooseberry
https://developer.blender.org/rBaf8c0c84f600a8c735fc8e4d514b404c962b5b03

Fix for applying the bending randomness factor.

A stupid hack is needed here, changing the way the factor is applied to
angular bending springs. In cloth sim the bending factor of individual
springs is applied as a mix value between the bending stiffness and a
max value, but this max value isn't even used in hair sim so that
approach becomes useless.

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

M	source/blender/blenkernel/intern/particle_system.c
M	source/blender/makesrna/intern/rna_particle.c
M	source/blender/physics/intern/BPH_mass_spring.cpp

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

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 3fc7185..b8fb0b4 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -3167,7 +3167,7 @@ static void hair_create_input_dm(ParticleSimulationData *sim, int totpoint, int
 		mul_m4_m4m4(root_mat, sim->ob->obmat, hairmat);
 		normalize_m4(root_mat);
 		
-		bending_stiffness = 1.0f - part->bending_random * psys_frand(psys, p + 666);
+		bending_stiffness = CLAMPIS(1.0f - part->bending_random * psys_frand(psys, p + 666), 0.0f, 1.0f);
 		
 		for (k=0, key=pa->hair; k<pa->totkey; k++,key++) {
 			ClothHairData *hair;
diff --git a/source/blender/makesrna/intern/rna_particle.c b/source/blender/makesrna/intern/rna_particle.c
index 6ebfafb..002cf84 100644
--- a/source/blender/makesrna/intern/rna_particle.c
+++ b/source/blender/makesrna/intern/rna_particle.c
@@ -2404,7 +2404,7 @@ static void rna_def_particle_settings(BlenderRNA *brna)
 	RNA_def_property_float_sdna(prop, NULL, "bending_random");
 	RNA_def_property_range(prop, 0.0f, 1.0f);
 	RNA_def_property_ui_text(prop, "Random Bending Stiffness", "Random stiffness of hairs");
-	RNA_def_property_update(prop, 0, "rna_Particle_reset");
+	RNA_def_property_update(prop, 0, "rna_Particle_redo");
 
 	/*TODO: not found in UI, readonly? */
 	prop = RNA_def_property(srna, "keys_step", PROP_INT, PROP_NONE);
diff --git a/source/blender/physics/intern/BPH_mass_spring.cpp b/source/blender/physics/intern/BPH_mass_spring.cpp
index e7b1029..7bc4941 100644
--- a/source/blender/physics/intern/BPH_mass_spring.cpp
+++ b/source/blender/physics/intern/BPH_mass_spring.cpp
@@ -482,7 +482,11 @@ 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);
+		/* XXX WARNING: angular bending springs for hair apply stiffness factor as an overall factor, unlike cloth springs!
+		 * this is crap, but needed due to cloth/hair mixing ...
+		 * max_bend factor is not even used for hair, so ...
+		 */
+		scaling = s->stiffness * parms->bending;
 		kb = scaling / (20.0f * (parms->avg_spring_len + FLT_EPSILON));
 		
 		scaling = parms->bending_damping;