1 files changed, 72 insertions, 9 deletions

diff --git a/source/blender/blenkernel/intern/effect.c b/source/blender/blenkernel/intern/effect.c
index 13e9bb1bf24..4104b6080c5 100644
--- a/source/blender/blenkernel/intern/effect.c
+++ b/source/blender/blenkernel/intern/effect.c
@@ -270,11 +270,71 @@ void BKE_effector_relations_free(ListBase *lb)
   }
 }
 
+/* Check that the force field isn't disabled via its flags. */
+static bool is_effector_enabled(PartDeflect *pd, bool use_rotation)
+{
+  switch (pd->forcefield) {
+    case PFIELD_BOID:
+    case PFIELD_GUIDE:
+      return true;
+
+    case PFIELD_TEXTURE:
+      return (pd->flag & PFIELD_DO_LOCATION) != 0 && pd->tex != NULL;
+
+    default:
+      if (use_rotation) {
+        return (pd->flag & (PFIELD_DO_LOCATION | PFIELD_DO_ROTATION)) != 0;
+      }
+      else {
+        return (pd->flag & PFIELD_DO_LOCATION) != 0;
+      }
+  }
+}
+
+/* Check that the force field won't have zero effect due to strength settings. */
+static bool is_effector_nonzero_strength(PartDeflect *pd)
+{
+  if (pd->f_strength != 0.0f) {
+    return true;
+  }
+
+  if (pd->forcefield == PFIELD_TEXTURE) {
+    return false;
+  }
+
+  if (pd->f_noise > 0.0f || pd->f_flow != 0.0f) {
+    return true;
+  }
+
+  switch (pd->forcefield) {
+    case PFIELD_BOID:
+    case PFIELD_GUIDE:
+      return true;
+
+    case PFIELD_VORTEX:
+      return pd->shape != PFIELD_SHAPE_POINT;
+
+    case PFIELD_DRAG:
+      return pd->f_damp != 0.0f;
+
+    default:
+      return false;
+  }
+}
+
+/* Check if the force field will affect its user. */
+static bool is_effector_relevant(PartDeflect *pd, EffectorWeights *weights, bool use_rotation)
+{
+  return (weights->weight[pd->forcefield] != 0.0f) && is_effector_enabled(pd, use_rotation) &&
+         is_effector_nonzero_strength(pd);
+}
+
 /* Create effective list of effectors from relations built beforehand. */
 ListBase *BKE_effectors_create(Depsgraph *depsgraph,
                                Object *ob_src,
                                ParticleSystem *psys_src,
-                               EffectorWeights *weights)
+                               EffectorWeights *weights,
+                               bool use_rotation)
 {
   Scene *scene = DEG_get_evaluated_scene(depsgraph);
   ListBase *relations = DEG_get_effector_relations(depsgraph, weights->group);
@@ -299,7 +359,8 @@ ListBase *BKE_effectors_create(Depsgraph *depsgraph,
       }
 
       PartDeflect *pd = (relation->pd == relation->psys->part->pd) ? part->pd : part->pd2;
-      if (weights->weight[pd->forcefield] == 0.0f) {
+
+      if (!is_effector_relevant(pd, weights, use_rotation)) {
         continue;
       }
 
@@ -310,7 +371,7 @@ ListBase *BKE_effectors_create(Depsgraph *depsgraph,
       if (ob == ob_src) {
         continue;
       }
-      if (weights->weight[ob->pd->forcefield] == 0.0f) {
+      if (!is_effector_relevant(ob->pd, weights, use_rotation)) {
         continue;
       }
       if (ob->pd->shape == PFIELD_SHAPE_POINTS && BKE_object_get_evaluated_mesh(ob) == NULL) {
@@ -903,7 +964,9 @@ static void do_texture_effector(EffectorCache *eff,
     madd_v3_v3fl(force, efd->nor, fac);
   }
 
-  add_v3_v3(total_force, force);
+  if (eff->pd->flag & PFIELD_DO_LOCATION) {
+    add_v3_v3(total_force, force);
+  }
 }
 static void do_physical_effector(EffectorCache *eff,
                                  EffectorData *efd,
@@ -918,6 +981,7 @@ static void do_physical_effector(EffectorCache *eff,
   float strength = pd->f_strength;
   float damp = pd->f_damp;
   float noise_factor = pd->f_noise;
+  float flow_falloff = efd->falloff;
 
   if (noise_factor > 0.0f) {
     strength += wind_func(rng, noise_factor);
@@ -1027,6 +1091,7 @@ static void do_physical_effector(EffectorCache *eff,
       break;
     case PFIELD_FLUIDFLOW:
       zero_v3(force);
+      flow_falloff = 0;
 #ifdef WITH_FLUID
       if (pd->f_source) {
         float density;
@@ -1036,8 +1101,7 @@ static void do_physical_effector(EffectorCache *eff,
             influence *= density;
           }
           mul_v3_fl(force, influence);
-          /* apply flow */
-          madd_v3_v3fl(total_force, point->vel, -pd->f_flow * influence);
+          flow_falloff = influence;
         }
       }
 #endif
@@ -1047,9 +1111,8 @@ static void do_physical_effector(EffectorCache *eff,
   if (pd->flag & PFIELD_DO_LOCATION) {
     madd_v3_v3fl(total_force, force, 1.0f / point->vel_to_sec);
 
-    if (ELEM(pd->forcefield, PFIELD_HARMONIC, PFIELD_DRAG, PFIELD_FLUIDFLOW) == 0 &&
-        pd->f_flow != 0.0f) {
-      madd_v3_v3fl(total_force, point->vel, -pd->f_flow * efd->falloff);
+    if (!ELEM(pd->forcefield, PFIELD_HARMONIC, PFIELD_DRAG) && pd->f_flow != 0.0f) {
+      madd_v3_v3fl(total_force, point->vel, -pd->f_flow * flow_falloff);
     }
   }