source/blender/blenkernel/BKE_bake_geometry_nodes_modifier.hh

@@ -48,8 +48,11 @@ struct PrevCache {
   SubFrame frame;
 };
 
+/**
+ * Baked data that corresponds to either a Simulation Output or Bake node.
+ */
 struct NodeBakeCache {
-  /** All cached frames. */
+  /** All cached frames sorted by frame. */
   Vector<std::unique_ptr<FrameCache>> frames;
 
   /** Where to load blobs from disk when loading the baked data lazily. */
@@ -59,15 +62,10 @@ struct NodeBakeCache {
   /** Used to avoid checking if a bake exists many times. */
   bool failed_finding_bake = false;
 
-  IndexRange frame_range() const
-  {
-    if (this->frames.is_empty()) {
-      return {};
-    }
-    const int start_frame = this->frames.first()->frame.frame();
-    const int end_frame = this->frames.last()->frame.frame();
-    return {start_frame, end_frame - start_frame + 1};
-  }
+  /** Range spanning from the first to the last baked frame. */
+  IndexRange frame_range() const;
+
+  void reset();
 };
 
 struct SimulationNodeCache {
@@ -89,21 +87,16 @@ struct BakeNodeCache {
 
 struct ModifierCache {
   mutable std::mutex mutex;
+  /**
+   * Set of nested node IDs (see #bNestedNodeRef) that is expected to be baked in the next
+   * evaluation. This is filled and cleared by the bake operator.
+   */
   Set<int> requested_bakes;
   Map<int, std::unique_ptr<SimulationNodeCache>> simulation_cache_by_id;
   Map<int, std::unique_ptr<BakeNodeCache>> bake_cache_by_id;
 
-  SimulationNodeCache *get_simulation_node_cache(const int id)
-  {
-    std::unique_ptr<SimulationNodeCache> *ptr = this->simulation_cache_by_id.lookup_ptr(id);
-    return ptr ? (*ptr).get() : nullptr;
-  }
-
-  BakeNodeCache *get_bake_node_cache(const int id)
-  {
-    std::unique_ptr<BakeNodeCache> *ptr = this->bake_cache_by_id.lookup_ptr(id);
-    return ptr ? (*ptr).get() : nullptr;
-  }
+  SimulationNodeCache *get_simulation_node_cache(const int id);
+  BakeNodeCache *get_bake_node_cache(const int id);
 };
 
 /**

source/blender/blenkernel/intern/bake_geometry_nodes_modifier.cc

@@ -36,6 +36,34 @@ void BakeNodeCache::reset()
   new (this) BakeNodeCache();
 }
 
+void NodeBakeCache::reset()
+{
+  std::destroy_at(this);
+  new (this) NodeBakeCache();
+}
+
+IndexRange NodeBakeCache::frame_range() const
+{
+  if (this->frames.is_empty()) {
+    return {};
+  }
+  const int start_frame = this->frames.first()->frame.frame();
+  const int end_frame = this->frames.last()->frame.frame();
+  return {start_frame, end_frame - start_frame + 1};
+}
+
+SimulationNodeCache *ModifierCache::get_simulation_node_cache(const int id)
+{
+  std::unique_ptr<SimulationNodeCache> *ptr = this->simulation_cache_by_id.lookup_ptr(id);
+  return ptr ? (*ptr).get() : nullptr;
+}
+
+BakeNodeCache *ModifierCache::get_bake_node_cache(const int id)
+{
+  std::unique_ptr<BakeNodeCache> *ptr = this->bake_cache_by_id.lookup_ptr(id);
+  return ptr ? (*ptr).get() : nullptr;
+}
+
 void scene_simulation_states_reset(Scene &scene)
 {
   FOREACH_SCENE_OBJECT_BEGIN (&scene, ob) {

source/blender/editors/space_action/action_draw.cc

@@ -880,6 +880,7 @@ void timeline_draw_cache(const SpaceAction *saction, const Object *ob, const Sce
         continue;
       }
       if (nmd->node_group->nested_node_refs_num == 0) {
+        /* Skip when there are no bake nodes or simulations. */
         continue;
       }
       const blender::bke::bake::ModifierCache &modifier_cache = *nmd->runtime->cache;

source/blender/modifiers/intern/MOD_nodes.cc

@@ -875,10 +875,7 @@ static bool try_find_baked_data(bake::NodeBakeCache &bake,
   if (meta_files.is_empty()) {
     return false;
   }
-  /* Reset bake. */
-  std::destroy_at(&bake);
-  new (&bake) bake::NodeBakeCache();
-
+  bake.reset();
   for (const bake::MetaFile &meta_file : meta_files) {
     auto frame_cache = std::make_unique<bake::FrameCache>();
     frame_cache->frame = meta_file.frame;
@@ -1253,6 +1250,7 @@ class NodesModifierBakeParams : public nodes::GeoNodesBakeParams {
 
     if (depsgraph_is_active_) {
       if (modifier_cache_->requested_bakes.contains(id)) {
+        /* This node is baked during the current evaluation. */
         auto &store_info = behavior.emplace<sim_output::StoreNewState>();
         store_info.store_fn = [modifier_cache = modifier_cache_,
                                node_cache = &node_cache,