Added an option for texture forcefields to use the root location of a particle for its texture coords.

Without this, animating grass would either look like seaweed (with low freq texture)
Or the grass would wrinkle up and get kinks (high freq texture)
This lets you use a high frequency texture while having straight grass.

6 files changed, 16 insertions, 13 deletions

diff --git a/source/blender/blenkernel/BKE_particle.h b/source/blender/blenkernel/BKE_particle.h
index 85fa079cef4..9ac3c148345 100644
--- a/source/blender/blenkernel/BKE_particle.h
+++ b/source/blender/blenkernel/BKE_particle.h
@@ -293,7 +293,7 @@ void psys_particle_on_dm(struct Object *ob, struct DerivedMesh *dm, int from, in
 void initialize_particle(struct ParticleData *pa, int p, struct Object *ob, struct ParticleSystem *psys, struct ParticleSystemModifierData *psmd);
 void reset_particle(struct ParticleData *pa, struct ParticleSystem *psys, struct ParticleSystemModifierData *psmd, struct Object *ob, float dtime, float cfra, float *vg_vel, float *vg_tan, float *vg_rot);
 
-void do_effectors(int pa_no, struct ParticleData *pa, struct ParticleKey *state, struct Object *ob, struct ParticleSystem *psys, float *force_field, float *vel,float framestep, float cfra);
+void do_effectors(int pa_no, struct ParticleData *pa, struct ParticleKey *state, struct Object *ob, struct ParticleSystem *psys, float *texco, float *force_field, float *vel,float framestep, float cfra);
 
 void psys_calc_dmcache(struct Object *ob, struct DerivedMesh *dm, struct ParticleSystem *psys);
 int psys_particle_dm_face_lookup(struct Object *ob, struct DerivedMesh *dm, int index, float *fw, struct LinkNode *node);
diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index 2538ddf511b..03d29a882c7 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -1682,7 +1682,7 @@ static void do_rough_end(float *loc, float t, float fac, float shape, ParticleKe
 
 	VECADD(state->co,state->co,rough);
 }
-static void do_path_effectors(Object *ob, ParticleSystem *psys, int i, ParticleCacheKey *ca, int k, int steps, float effector, float dfra, float cfra, float *length, float *vec)
+static void do_path_effectors(Object *ob, ParticleSystem *psys, int i, ParticleCacheKey *ca, int k, int steps, float *rootco, float effector, float dfra, float cfra, float *length, float *vec)
 {
 	float force[3] = {0.0f,0.0f,0.0f}, vel[3] = {0.0f,0.0f,0.0f};
 	ParticleKey eff_key;
@@ -1693,7 +1693,7 @@ static void do_path_effectors(Object *ob, ParticleSystem *psys, int i, ParticleC
 	QUATCOPY(eff_key.rot,(ca-1)->rot);
 
 	pa= psys->particles+i;
-	do_effectors(i, pa, &eff_key, ob, psys, force, vel, dfra, cfra);
+	do_effectors(i, pa, &eff_key, ob, psys, rootco, force, vel, dfra, cfra);
 
 	VecMulf(force, effector*pow((float)k / (float)steps, 100.0f * psys->part->eff_hair) / (float)steps);
 
@@ -2102,7 +2102,7 @@ void psys_thread_create_path(ParticleThread *thread, struct ChildParticle *cpa,
 	if(part->flag & PART_CHILD_EFFECT) {
 		for(k=0,state=keys; k<=ctx->steps; k++,state++) {
 			if(k) {
-				do_path_effectors(ob, psys, cpa->pa[0], state, k, ctx->steps, pa_effector, 0.0f, ctx->cfra, &eff_length, eff_vec);
+				do_path_effectors(ob, psys, cpa->pa[0], state, k, ctx->steps, keys->co, pa_effector, 0.0f, ctx->cfra, &eff_length, eff_vec);
 			}
 			else {
 				VecSubf(eff_vec,(state+1)->co,state->co);
@@ -2527,7 +2527,7 @@ void psys_cache_paths(Object *ob, ParticleSystem *psys, float cfra, int editupda
 		for(k=0, ca=cache[i]; k<=steps; k++, ca++) {
 			/* apply effectors */
 			if(!(psys->part->flag & PART_CHILD_EFFECT) && edit==0 && k)
-				do_path_effectors(ob, psys, i, ca, k, steps, effector, dfra, cfra, &length, vec);
+				do_path_effectors(ob, psys, i, ca, k, steps, cache[i]->co, effector, dfra, cfra, &length, vec);
 
 			/* apply guide curves to path data */
 			if(edit==0 && psys->effectors.first && (psys->part->flag & PART_CHILD_GUIDE)==0)
diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 9ba704e6c8d..5531b600f97 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -2603,7 +2603,7 @@ static void precalc_effectors(Object *ob, ParticleSystem *psys, ParticleSystemMo
 
 
 /* calculate forces that all effectors apply to a particle*/
-void do_effectors(int pa_no, ParticleData *pa, ParticleKey *state, Object *ob, ParticleSystem *psys, float *force_field, float *vel,float framestep, float cfra)
+void do_effectors(int pa_no, ParticleData *pa, ParticleKey *state, Object *ob, ParticleSystem *psys, float *rootco, float *force_field, float *vel,float framestep, float cfra)
 {
 	Object *eob;
 	ParticleSystem *epsys;
@@ -2650,14 +2650,15 @@ void do_effectors(int pa_no, ParticleData *pa, ParticleKey *state, Object *ob, P
 
 				if(falloff<=0.0f)
 					;	/* don't do anything */
-				else if(pd->forcefield==PFIELD_TEXTURE)
+				else if(pd->forcefield==PFIELD_TEXTURE) {
 					do_texture_effector(pd->tex, pd->tex_mode, pd->flag&PFIELD_TEX_2D, pd->tex_nabla,
-										pd->flag & PFIELD_TEX_OBJECT, state->co, eob->obmat,
-										pd->f_strength, falloff, force_field);
-				else
+									pd->flag & PFIELD_TEX_OBJECT, (pd->flag & PFIELD_TEX_ROOTCO) ? rootco : state->co, eob->obmat,
+									pd->f_strength, falloff, force_field);
+				} else {
 					do_physical_effector(pd->forcefield,pd->f_strength,distance,
 										falloff,pd->f_dist,pd->f_damp,eob->obmat[2],vec_to_part,
 										pa->state.vel,force_field,pd->flag&PFIELD_PLANAR);
+				}
 			}
 			if(ec->type & PSYS_EC_PARTICLE){
 				int totepart;
@@ -2757,7 +2758,7 @@ static void apply_particle_forces(int pa_no, ParticleData *pa, Object *ob, Parti
 		tvel[0]=tvel[1]=tvel[2]=0.0;
 		/* add effectors */
 		if(part->type != PART_HAIR)
-			do_effectors(pa_no,pa,states+i,ob,psys,force,tvel,dfra,fra);
+			do_effectors(pa_no,pa,states+i,ob,psys,states->co,force,tvel,dfra,fra);
 
 		/* calculate air-particle interaction */
 		if(part->dragfac!=0.0f){
diff --git a/source/blender/makesdna/DNA_object_force.h b/source/blender/makesdna/DNA_object_force.h
index c2500fba7fe..cdee50cfef4 100644
--- a/source/blender/makesdna/DNA_object_force.h
+++ b/source/blender/makesdna/DNA_object_force.h
@@ -163,6 +163,7 @@ typedef struct SoftBody {
 #define PFIELD_USEMIN			256
 #define PFIELD_USEMAXR			512
 #define PFIELD_USEMINR			1024
+#define PFIELD_TEX_ROOTCO		2048
 
 /* pd->falloff */
 #define PFIELD_FALL_SPHERE		0
diff --git a/source/blender/src/buttons_object.c b/source/blender/src/buttons_object.c
index e67c9444c1f..54c592173ce 100644
--- a/source/blender/src/buttons_object.c
+++ b/source/blender/src/buttons_object.c
@@ -3417,7 +3417,8 @@ static void object_panel_fields(Object *ob)
 				if(pd->forcefield == PFIELD_TEXTURE){
 					uiDefIDPoinBut(block, field_testTexture, ID_TE, B_FIELD_CHANGE, "Texture: ", 10, 120, 140, 20, &pd->tex, "Texture to use as force");
 					uiDefButBitS(block, TOG, PFIELD_TEX_OBJECT, B_FIELD_CHANGE, "Use Object Co",	10,100,140,20, &pd->flag, 0.0, 0, 0, 0, "Use object/global coordinates for texture");
-					uiDefButBitS(block, TOG, PFIELD_TEX_2D, B_FIELD_CHANGE, "2D",	10,80,140,20, &pd->flag, 0.0, 0, 0, 0, "Apply force only in 2d");
+					uiDefButBitS(block, TOG, PFIELD_TEX_ROOTCO, B_FIELD_CHANGE, "Root TexCo",	10,80,120,20, &pd->flag, 0.0, 0, 0, 0, "Texture coords from root particle locations");
+					uiDefButBitS(block, TOG, PFIELD_TEX_2D, B_FIELD_CHANGE, "2D",	130,80,20,20, &pd->flag, 0.0, 0, 0, 0, "Apply force only in 2d");
 				}
 				else if(pd->forcefield == PFIELD_HARMONIC) 
 					uiDefButF(block, NUM, B_FIELD_CHANGE, "Damp: ",	10,120,140,20, &pd->f_damp, 0, 10, 10, 0, "Damping of the harmonic force");	
diff --git a/source/blender/src/toolbox.c b/source/blender/src/toolbox.c
index 0db63c787ae..c2773611bb2 100644
--- a/source/blender/src/toolbox.c
+++ b/source/blender/src/toolbox.c
@@ -2268,7 +2268,7 @@ void toolbox_generic( TBitem *generic_menu )
 	uiBut *but;
 	TBitem *menu;
 	int dx=96;
-	short event, mval[2], tot=0;
+	short event, mval[2];
 	long ypos = -5;
 	
 	tb_mainx= -32;