[Bf-blender-cvs] [cfa92fc] gooseberry: Fix for clumping noise randomness being unstable under deformation.

[Lukas Tönne]

Commit: cfa92fcc6f1c90caa3ec5139a9d76076a710ea2a
Author: Lukas Tönne
Date:   Tue Feb 24 16:36:15 2015 +0100
Branches: gooseberry
https://developer.blender.org/rBcfa92fcc6f1c90caa3ec5139a9d76076a710ea2a

Fix for clumping noise randomness being unstable under deformation.

This randomisation was using the deformed parent coordinates for
calculating noise vectors, which causes unwanted movement as the parent
hair deforms. Instead the `orco` coordinates must be used for all noise
vectors, since these are from the undeformed mesh.

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

M	source/blender/blenkernel/intern/particle.c
M	source/blender/blenkernel/intern/particle_child.c

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

diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index 7469dcd..f081c96 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -1362,7 +1362,7 @@ void psys_particle_on_emitter(ParticleSystemModifierData *psmd, int from, int in
 
 extern void do_kink(ParticleKey *state, const float par_co[3], const float par_vel[3], const float par_rot[4], float time, float freq, float shape, float amplitude, float flat,
                     short type, short axis, float obmat[4][4], int smooth_start);
-extern float do_clump(ParticleKey *state, const float par_co[3], float time, const float orco_offset[3], float clumpfac, float clumppow, float pa_clump,
+extern float do_clump(ParticleKey *state, const float par_co[3], const float par_orco[3], float time, const float orco[3], float clumpfac, float clumppow, float pa_clump,
                       bool use_clump_noise, float clump_noise_size, CurveMapping *clumpcurve, float clump_noise_random, float clump_noise_random_size, float mat[4][4]);
 
 void precalc_guides(ParticleSimulationData *sim, ListBase *effectors)
@@ -1487,11 +1487,12 @@ int do_guides(ParticleSettings *part, ListBase *effectors, ParticleKey *state, i
 			float par_co[3] = {0.0f, 0.0f, 0.0f};
 			float par_vel[3] = {0.0f, 0.0f, 0.0f};
 			float par_rot[4] = {1.0f, 0.0f, 0.0f, 0.0f};
-			float orco_offset[3] = {0.0f, 0.0f, 0.0f};
+			float par_orco[3] = {0.0f, 0.0f, 0.0f};
+			float orco[3] = {0.0f, 0.0f, 0.0f};
 			
 			copy_v3_v3(key.co, vec_to_point);
 			do_kink(&key, par_co, par_vel, par_rot, guidetime, pd->kink_freq, pd->kink_shape, pd->kink_amp, 0.f, pd->kink, pd->kink_axis, 0, 0);
-			do_clump(&key, par_co, guidetime, orco_offset, pd->clump_fac, pd->clump_pow, 1.0f,
+			do_clump(&key, par_co, par_orco, guidetime, orco, pd->clump_fac, pd->clump_pow, 1.0f,
 			         part->child_flag & PART_CHILD_USE_CLUMP_NOISE, part->clump_noise_size, clumpcurve,
 			         part->clump_noise_random, part->clump_noise_random_size, NULL);
 			copy_v3_v3(vec_to_point, key.co);
diff --git a/source/blender/blenkernel/intern/particle_child.c b/source/blender/blenkernel/intern/particle_child.c
index 1636840..5c11584 100644
--- a/source/blender/blenkernel/intern/particle_child.c
+++ b/source/blender/blenkernel/intern/particle_child.c
@@ -41,7 +41,7 @@ struct Material;
 
 void do_kink(ParticleKey *state, const float par_co[3], const float par_vel[3], const float par_rot[4], float time, float freq, float shape, float amplitude, float flat,
              short type, short axis, float obmat[4][4], int smooth_start);
-float do_clump(ParticleKey *state, const float par_co[3], float time, const float orco_offset[3], float clumpfac, float clumppow, float pa_clump,
+float do_clump(ParticleKey *state, const float par_co[3], const float par_orco[3], float time, const float orco[3], float clumpfac, float clumppow, float pa_clump,
                bool use_clump_noise, float clump_noise_size, CurveMapping *clumpcurve, float clump_noise_random, float clump_noise_random_size, float mat[4][4]);
 void do_child_modifiers(ParticleSimulationData *sim,
                         ParticleTexture *ptex, const float par_co[3], const float par_vel[3], const float par_rot[4], const float par_orco[3],
@@ -598,7 +598,7 @@ BLI_INLINE void simple_roughness(float mat[4][4], float size, float factor, cons
 	madd_v3_v3fl(result, mat[2], factor * rough[2]);
 }
 
-float do_clump(ParticleKey *state, const float par_co[3], float time, const float orco_offset[3], float clumpfac, float clumppow, float pa_clump,
+float do_clump(ParticleKey *state, const float par_co[3], const float par_orco[3], float time, const float orco[3], float clumpfac, float clumppow, float pa_clump,
                bool use_clump_noise, float clump_noise_size, CurveMapping *clumpcurve, float clump_noise_random, float clump_noise_random_size, float mat[4][4])
 {
 	float clump;
@@ -607,16 +607,17 @@ float do_clump(ParticleKey *state, const float par_co[3], float time, const floa
 	zero_v3(rough_offset);
 	
 	if (use_clump_noise && clump_noise_size != 0.0f) {
-		float center[3], noisevec[3];
+		float center[3], noisevec[3], orco_offset[3];
 		float da[4], pa[12];
 		
+		sub_v3_v3v3(orco_offset, orco, par_orco);
 		mul_v3_v3fl(noisevec, orco_offset, 1.0f / clump_noise_size);
 		voronoi(noisevec[0], noisevec[1], noisevec[2], da, pa, 1.0f, 0);
 		mul_v3_fl(&pa[0], clump_noise_size);
-		add_v3_v3v3(center, par_co, &pa[0]);
+		add_v3_v3v3(center, par_orco, &pa[0]);
 		
 		if (clump_noise_random != 0.0f && mat) {
-			simple_roughness(mat, clump_noise_random_size, clump_noise_random, center, 1.0f, rough_offset);
+			simple_roughness(mat, clump_noise_random_size, clump_noise_random, center, time, rough_offset);
 		}
 		
 		do_clump_level(state->co, state->co, center, time, clumpfac, clumppow, pa_clump, clumpcurve);
@@ -697,11 +698,9 @@ void do_child_modifiers(ParticleSimulationData *sim, ParticleTexture *ptex, cons
 		guided = do_guides(sim->psys->part, sim->psys->effectors, (ParticleKey *)state, cpa->parent, t);
 
 	if (guided == 0) {
-		float orco_offset[3];
 		float clump;
 		
-		sub_v3_v3v3(orco_offset, orco, par_orco);
-		clump = do_clump(state, par_co, t, orco_offset, part->clumpfac, part->clumppow, ptex ? ptex->clump : 1.f,
+		clump = do_clump(state, par_co, par_orco, t, orco, part->clumpfac, part->clumppow, ptex ? ptex->clump : 1.f,
 		                 part->child_flag & PART_CHILD_USE_CLUMP_NOISE, part->clump_noise_size, clumpcurve,
 		                 part->clump_noise_random, part->clump_noise_random_size, mat);