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.

1 files changed, 4 insertions, 4 deletions

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)