5 files changed, 6 insertions, 53 deletions
diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index ceaeda6e798..269ad8ecc5b 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -1225,11 +1225,6 @@ class CyclesCurveRenderSettings(bpy.types.PropertyGroup):
         items=enum_curve_shape,
         default='RIBBONS',
     )
-    use_curves: BoolProperty(
-        name="Use Cycles Hair Rendering",
-        description="Activate Cycles hair rendering for particle system",
-        default=True,
-    )
     subdivisions: IntProperty(
         name="Subdivisions",
         description="Number of subdivisions used in Cardinal curve intersection (power of 2)",
diff --git a/intern/cycles/blender/addon/ui.py b/intern/cycles/blender/addon/ui.py
index daab26d8ec0..592c59cc661 100644
--- a/intern/cycles/blender/addon/ui.py
+++ b/intern/cycles/blender/addon/ui.py
@@ -387,13 +387,6 @@ class CYCLES_RENDER_PT_hair(CyclesButtonsPanel, Panel):
     bl_label = "Hair"
     bl_options = {'DEFAULT_CLOSED'}
 
-    def draw_header(self, context):
-        layout = self.layout
-        scene = context.scene
-        ccscene = scene.cycles_curves
-
-        layout.prop(ccscene, "use_curves", text="")
-
     def draw(self, context):
         layout = self.layout
         layout.use_property_split = True
@@ -402,8 +395,6 @@ class CYCLES_RENDER_PT_hair(CyclesButtonsPanel, Panel):
         scene = context.scene
         ccscene = scene.cycles_curves
 
-        layout.active = ccscene.use_curves
-
         col = layout.column()
         col.prop(ccscene, "shape", text="Shape")
         if ccscene.shape == 'RIBBONS':
diff --git a/intern/cycles/blender/blender_curves.cpp b/intern/cycles/blender/blender_curves.cpp
index a2a0392d4d5..e1f84925987 100644
--- a/intern/cycles/blender/blender_curves.cpp
+++ b/intern/cycles/blender/blender_curves.cpp
@@ -507,42 +507,6 @@ static void ExportCurveSegmentsMotion(Hair *hair, ParticleCurveData *CData, int
 
 /* Hair Curve Sync */
 
-void BlenderSync::sync_curve_settings(BL::Depsgraph &b_depsgraph)
-{
-  PointerRNA csscene = RNA_pointer_get(&b_scene.ptr, "cycles_curves");
-
-  CurveSystemManager *curve_system_manager = scene->curve_system_manager;
-  CurveSystemManager prev_curve_system_manager = *curve_system_manager;
-
-  curve_system_manager->use_curves = get_boolean(csscene, "use_curves");
-
-  curve_system_manager->curve_shape = (CurveShapeType)get_enum(
-      csscene, "shape", CURVE_NUM_SHAPE_TYPES, CURVE_THICK);
-  curve_system_manager->subdivisions = get_int(csscene, "subdivisions");
-
-  if (curve_system_manager->modified_mesh(prev_curve_system_manager)) {
-    BL::Depsgraph::objects_iterator b_ob;
-
-    for (b_depsgraph.objects.begin(b_ob); b_ob != b_data.objects.end(); ++b_ob) {
-      if (object_is_mesh(*b_ob)) {
-        BL::Object::particle_systems_iterator b_psys;
-        for (b_ob->particle_systems.begin(b_psys); b_psys != b_ob->particle_systems.end();
-             ++b_psys) {
-          if ((b_psys->settings().render_type() == BL::ParticleSettings::render_type_PATH) &&
-              (b_psys->settings().type() == BL::ParticleSettings::type_HAIR)) {
-            BL::ID key = BKE_object_is_modified(*b_ob) ? *b_ob : b_ob->data();
-            geometry_map.set_recalc(key);
-            object_map.set_recalc(*b_ob);
-          }
-        }
-      }
-    }
-  }
-
-  if (curve_system_manager->modified(prev_curve_system_manager))
-    curve_system_manager->tag_update(scene);
-}
-
 bool BlenderSync::object_has_particle_hair(BL::Object b_ob)
 {
   /* Test if the object has a particle modifier with hair. */
@@ -867,7 +831,7 @@ void BlenderSync::sync_hair(BL::Depsgraph b_depsgraph,
   hair->clear();
   hair->used_shaders = used_shaders;
 
-  if (view_layer.use_hair && scene->curve_system_manager->use_curves) {
+  if (view_layer.use_hair) {
 #ifdef WITH_NEW_OBJECT_TYPES
     if (b_ob.type() == BL::Object::type_HAIR) {
       /* Hair object. */
diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index f5fd6f31c75..7a6047ca6a6 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -212,7 +212,6 @@ void BlenderSync::sync_data(BL::RenderSettings &b_render,
   sync_film(b_v3d);
   sync_shaders(b_depsgraph, b_v3d);
   sync_images();
-  sync_curve_settings(b_depsgraph);
 
   geometry_synced.clear(); /* use for objects and motion sync */
 
@@ -732,6 +731,11 @@ SceneParams BlenderSync::get_scene_params(BL::Scene &b_scene, bool background)
   params.use_bvh_unaligned_nodes = RNA_boolean_get(&cscene, "debug_use_hair_bvh");
   params.num_bvh_time_steps = RNA_int_get(&cscene, "debug_bvh_time_steps");
 
+  PointerRNA csscene = RNA_pointer_get(&b_scene.ptr, "cycles_curves");
+  params.hair_subdivisions = get_int(csscene, "subdivisions");
+  params.hair_shape = (CurveShapeType)get_enum(
+      csscene, "shape", CURVE_NUM_SHAPE_TYPES, CURVE_THICK);
+
   if (background && params.shadingsystem != SHADINGSYSTEM_OSL)
     params.persistent_data = r.use_persistent_data();
   else
diff --git a/intern/cycles/blender/blender_sync.h b/intern/cycles/blender/blender_sync.h
index 3c39cfd9446..25032e8d0fa 100644
--- a/intern/cycles/blender/blender_sync.h
+++ b/intern/cycles/blender/blender_sync.h
@@ -159,7 +159,6 @@ class BlenderSync {
   void sync_hair(Hair *hair, BL::Object &b_ob, bool motion, int motion_step = 0);
   void sync_particle_hair(
       Hair *hair, BL::Mesh &b_mesh, BL::Object &b_ob, bool motion, int motion_step = 0);
-  void sync_curve_settings(BL::Depsgraph &b_depsgraph);
   bool object_has_particle_hair(BL::Object b_ob);
 
   /* Camera */