source/blender/blenkernel/BKE_simulation_state.hh

@@ -162,7 +162,7 @@ class ModifierSimulationCache {
   CacheState cache_state_ = CacheState::Valid;
   bool failed_finding_bake_ = false;
 
-  void try_discover_bake(StringRefNull meta_dir, StringRefNull bdata_dir);
+  void try_discover_bake(StringRefNull absolute_bake_dir);
 
   bool has_state_at_frame(const SubFrame &frame) const;
   bool has_states() const;

source/blender/blenkernel/BKE_simulation_state_serialize.hh

@@ -143,12 +143,11 @@ class DiskBDataWriter : public BDataWriter {
 };
 
 /**
- * Get the directory that contains all baked simulation data for the given modifier. This is a
+ * Get the directory that contains all baked simulation data for the given modifier.
- * parent directory of the two directories below.
  */
-std::string get_bake_directory(const Main &bmain, const Object &object, const ModifierData &md);
+std::string get_default_modifier_bake_directory(const Main &bmain,
-std::string get_bdata_directory(const Main &bmain, const Object &object, const ModifierData &md);
+                                                const Object &object,
-std::string get_meta_directory(const Main &bmain, const Object &object, const ModifierData &md);
+                                                const ModifierData &md);
 
 /**
  * Encode the simulation state in a #DictionaryValue which also contains references to external

source/blender/blenkernel/intern/simulation_state.cc

@@ -37,19 +37,24 @@ StringSimulationStateItem::StringSimulationStateItem(std::string value) : value_
 {
 }
 
-void ModifierSimulationCache::try_discover_bake(const StringRefNull meta_dir,
+void ModifierSimulationCache::try_discover_bake(const StringRefNull absolute_bake_dir)
-                                                const StringRefNull bdata_dir)
 {
   if (failed_finding_bake_) {
     return;
   }
-  if (!BLI_is_dir(meta_dir.c_str()) || !BLI_is_dir(bdata_dir.c_str())) {
+
+  char meta_dir[FILE_MAX];
+  BLI_path_join(meta_dir, sizeof(meta_dir), absolute_bake_dir.c_str(), "meta");
+  char bdata_dir[FILE_MAX];
+  BLI_path_join(bdata_dir, sizeof(bdata_dir), absolute_bake_dir.c_str(), "bdata");
+
+  if (!BLI_is_dir(meta_dir) || !BLI_is_dir(bdata_dir)) {
     failed_finding_bake_ = true;
     return;
   }
 
   direntry *dir_entries = nullptr;
-  const int dir_entries_num = BLI_filelist_dir_contents(meta_dir.c_str(), &dir_entries);
+  const int dir_entries_num = BLI_filelist_dir_contents(meta_dir, &dir_entries);
   BLI_SCOPED_DEFER([&]() { BLI_filelist_free(dir_entries, dir_entries_num); });
 
   if (dir_entries_num == 0) {

source/blender/blenkernel/intern/simulation_state_serialize.cc

@@ -42,26 +42,18 @@ static std::string escape_name(const StringRef name)
   return ss.str();
 }
 
-static std::string get_blendcache_directory(const Main &bmain)
+static std::string get_blend_file_name(const Main &bmain)
 {
-  StringRefNull blend_file_path = BKE_main_blendfile_path(&bmain);
+  const StringRefNull blend_file_path = BKE_main_blendfile_path(&bmain);
-  char blend_directory[FILE_MAX];
   char blend_name[FILE_MAX];
-  BLI_path_split_dir_file(blend_file_path.c_str(),
+
-                          blend_directory,
+  BLI_path_split_file_part(blend_file_path.c_str(), blend_name, sizeof(blend_name));
-                          sizeof(blend_directory),
-                          blend_name,
-                          sizeof(blend_name));
   const int64_t type_start_index = StringRef(blend_name).rfind(".");
   if (type_start_index == StringRef::not_found) {
     return "";
   }
   blend_name[type_start_index] = '\0';
-  const std::string blendcache_name = "blendcache_" + StringRef(blend_name);
+  return "blendcache_" + StringRef(blend_name);
-
-  char blendcache_dir[FILE_MAX];
-  BLI_path_join(blendcache_dir, sizeof(blendcache_dir), blend_directory, blendcache_name.c_str());
-  return blendcache_dir;
 }
 
 static std::string get_modifier_sim_name(const Object &object, const ModifierData &md)
@@ -71,29 +63,18 @@ static std::string get_modifier_sim_name(const Object &object, const ModifierDat
   return "sim_" + object_name_escaped + "_" + modifier_name_escaped;
 }
 
-std::string get_bake_directory(const Main &bmain, const Object &object, const ModifierData &md)
+std::string get_default_modifier_bake_directory(const Main &bmain,
+                                                const Object &object,
+                                                const ModifierData &md)
 {
-  char bdata_dir[FILE_MAX];
+  char dir[FILE_MAX];
-  BLI_path_join(bdata_dir,
+  /* Make path that's relative to the .blend file. */
-                sizeof(bdata_dir),
+  BLI_path_join(dir,
-                get_blendcache_directory(bmain).c_str(),
+                sizeof(dir),
+                "//",
+                get_blend_file_name(bmain).c_str(),
                 get_modifier_sim_name(object, md).c_str());
-  return bdata_dir;
+  return dir;
-}
-
-std::string get_bdata_directory(const Main &bmain, const Object &object, const ModifierData &md)
-{
-  char bdata_dir[FILE_MAX];
-  BLI_path_join(
-      bdata_dir, sizeof(bdata_dir), get_bake_directory(bmain, object, md).c_str(), "bdata");
-  return bdata_dir;
-}
-
-std::string get_meta_directory(const Main &bmain, const Object &object, const ModifierData &md)
-{
-  char meta_dir[FILE_MAX];
-  BLI_path_join(meta_dir, sizeof(meta_dir), get_bake_directory(bmain, object, md).c_str(), "meta");
-  return meta_dir;
 }
 
 std::shared_ptr<DictionaryValue> BDataSlice::serialize() const

source/blender/blenloader/intern/versioning_300.cc

@@ -67,6 +67,7 @@
 #include "BKE_modifier.h"
 #include "BKE_node.hh"
 #include "BKE_screen.h"
+#include "BKE_simulation_state_serialize.hh"
 #include "BKE_workspace.h"
 
 #include "RNA_access.h"
@@ -4483,5 +4484,21 @@ void blo_do_versions_300(FileData *fd, Library * /*lib*/, Main *bmain)
     /* Keep this block, even when empty. */
 
     BKE_animdata_main_cb(bmain, version_liboverride_nla_frame_start_end, NULL);
+
+    /* Store simulation bake directory in geometry nodes modifier. */
+    LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+      LISTBASE_FOREACH (ModifierData *, md, &ob->modifiers) {
+        if (md->type != eModifierType_Nodes) {
+          continue;
+        }
+        NodesModifierData *nmd = reinterpret_cast<NodesModifierData *>(md);
+        if (nmd->simulation_bake_directory) {
+          continue;
+        }
+        const std::string bake_dir = blender::bke::sim::get_default_modifier_bake_directory(
+            *bmain, *ob, *md);
+        nmd->simulation_bake_directory = BLI_strdup(bake_dir.c_str());
+      }
+    }
   }
 }

source/blender/editors/object/object_bake_simulation.cc

@@ -209,8 +209,7 @@ static bool bake_simulation_poll(bContext *C)
 
 struct ModifierBakeData {
   NodesModifierData *nmd;
-  std::string meta_dir;
+  std::string absolute_bake_dir;
-  std::string bdata_dir;
   std::unique_ptr<bke::sim::BDataSharing> bdata_sharing;
 };
 
@@ -244,6 +243,9 @@ static void bake_simulation_job_startjob(void *customdata,
     if (!BKE_id_is_editable(job.bmain, &object->id)) {
       continue;
     }
+
+    const char *base_path = ID_BLEND_PATH(job.bmain, &object->id);
+
     ObjectBakeData bake_data;
     bake_data.object = object;
     LISTBASE_FOREACH (ModifierData *, md, &object->modifiers) {
@@ -252,10 +254,14 @@ static void bake_simulation_job_startjob(void *customdata,
         if (nmd->simulation_cache != nullptr) {
           nmd->simulation_cache->reset();
         }
-        bake_data.modifiers.append({nmd,
+        if (StringRef(nmd->simulation_bake_directory).is_empty()) {
-                                    bke::sim::get_meta_directory(*job.bmain, *object, *md),
+          nmd->simulation_bake_directory = BLI_strdup(
-                                    bke::sim::get_bdata_directory(*job.bmain, *object, *md),
+              bke::sim::get_default_modifier_bake_directory(*job.bmain, *object, *md).c_str());
-                                    std::make_unique<BDataSharing>()});
+        }
+        char absolute_bake_dir[FILE_MAX];
+        STRNCPY(absolute_bake_dir, nmd->simulation_bake_directory);
+        BLI_path_abs(absolute_bake_dir, base_path);
+        bake_data.modifiers.append({nmd, absolute_bake_dir, std::make_unique<BDataSharing>()});
       }
     }
     objects_to_bake.append(std::move(bake_data));
@@ -305,12 +311,14 @@ static void bake_simulation_job_startjob(void *customdata,
         char bdata_path[FILE_MAX];
         BLI_path_join(bdata_path,
                       sizeof(bdata_path),
-                      modifier_bake_data.bdata_dir.c_str(),
+                      modifier_bake_data.absolute_bake_dir.c_str(),
+                      "bdata",
                       bdata_file_name.c_str());
         char meta_path[FILE_MAX];
         BLI_path_join(meta_path,
                       sizeof(meta_path),
-                      modifier_bake_data.meta_dir.c_str(),
+                      modifier_bake_data.absolute_bake_dir.c_str(),
+                      "meta",
                       meta_file_name.c_str());
 
         BLI_file_ensure_parent_dir_exists(bdata_path);
@@ -429,21 +437,25 @@ static int delete_baked_simulation_exec(bContext *C, wmOperator *op)
   }
 
   for (Object *object : objects) {
+    const char *base_path = ID_BLEND_PATH(bmain, &object->id);
     LISTBASE_FOREACH (ModifierData *, md, &object->modifiers) {
       if (md->type == eModifierType_Nodes) {
         NodesModifierData *nmd = reinterpret_cast<NodesModifierData *>(md);
-        const std::string bake_directory = bke::sim::get_bake_directory(*bmain, *object, *md);
-        if (BLI_exists(bake_directory.c_str())) {
-          if (BLI_delete(bake_directory.c_str(), true, true)) {
-            BKE_reportf(op->reports,
-                        RPT_ERROR,
-                        "Failed to remove bake directory %s",
-                        bake_directory.c_str());
-          }
-        }
         if (nmd->simulation_cache != nullptr) {
           nmd->simulation_cache->reset();
         }
+        if (StringRef(nmd->simulation_bake_directory).is_empty()) {
+          continue;
+        }
+        char absolute_bake_dir[FILE_MAX];
+        STRNCPY(absolute_bake_dir, nmd->simulation_bake_directory);
+        BLI_path_abs(absolute_bake_dir, base_path);
+        if (BLI_exists(absolute_bake_dir)) {
+          if (BLI_delete(absolute_bake_dir, true, true)) {
+            BKE_reportf(
+                op->reports, RPT_ERROR, "Failed to remove bake directory %s", absolute_bake_dir);
+          }
+        }
       }
     }
 

source/blender/makesdna/DNA_modifier_types.h

@@ -2319,6 +2319,11 @@ typedef struct NodesModifierData {
   ModifierData modifier;
   struct bNodeTree *node_group;
   struct NodesModifierSettings settings;
+  /**
+   * Directory where baked simulation states are stored. This may be relative to the .blend file.
+   */
+  char *simulation_bake_directory;
+  void *_pad;
 
   /**
    * Contains logged information from the last evaluation.

source/blender/modifiers/intern/MOD_nodes.cc

@@ -15,6 +15,7 @@
 #include "BLI_listbase.h"
 #include "BLI_math_vector_types.hh"
 #include "BLI_multi_value_map.hh"
+#include "BLI_path_util.h"
 #include "BLI_set.hh"
 #include "BLI_string.h"
 #include "BLI_string_search.h"
@@ -1152,9 +1153,14 @@ static void prepare_simulation_states_for_evaluation(const NodesModifierData &nm
       if (nmd_orig.simulation_cache->cache_state() != bke::sim::CacheState::Baked &&
           !bmain_path.is_empty())
       {
-        nmd_orig.simulation_cache->try_discover_bake(
+        if (!StringRef(nmd.simulation_bake_directory).is_empty()) {
-            bke::sim::get_meta_directory(*bmain, *ctx.object, nmd.modifier),
+          if (const char *base_path = ID_BLEND_PATH(bmain, &ctx.object->id)) {
-            bke::sim::get_bdata_directory(*bmain, *ctx.object, nmd.modifier));
+            char absolute_bake_dir[FILE_MAX];
+            STRNCPY(absolute_bake_dir, nmd.simulation_bake_directory);
+            BLI_path_abs(absolute_bake_dir, base_path);
+            nmd_orig.simulation_cache->try_discover_bake(absolute_bake_dir);
+          }
+        }
       }
     }
 
@@ -1995,6 +2001,8 @@ static void blendWrite(BlendWriter *writer, const ID * /*id_owner*/, const Modif
 
   BLO_write_struct(writer, NodesModifierData, nmd);
 
+  BLO_write_string(writer, nmd->simulation_bake_directory);
+
   if (nmd->settings.properties != nullptr) {
     Map<IDProperty *, IDPropertyUIDataBool *> boolean_props;
     if (!BLO_write_is_undo(writer)) {
@@ -2033,6 +2041,7 @@ static void blendWrite(BlendWriter *writer, const ID * /*id_owner*/, const Modif
 static void blendRead(BlendDataReader *reader, ModifierData *md)
 {
   NodesModifierData *nmd = reinterpret_cast<NodesModifierData *>(md);
+  BLO_read_data_address(reader, &nmd->simulation_bake_directory);
   if (nmd->node_group == nullptr) {
     nmd->settings.properties = nullptr;
   }
@@ -2053,6 +2062,9 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
 
   tnmd->runtime_eval_log = nullptr;
   tnmd->simulation_cache = nullptr;
+  tnmd->simulation_bake_directory = nmd->simulation_bake_directory ?
+                                        BLI_strdup(nmd->simulation_bake_directory) :
+                                        nullptr;
 
   if (nmd->settings.properties != nullptr) {
     tnmd->settings.properties = IDP_CopyProperty_ex(nmd->settings.properties, flag);
@@ -2068,6 +2080,7 @@ static void freeData(ModifierData *md)
   }
 
   MEM_delete(nmd->simulation_cache);
+  MEM_SAFE_FREE(nmd->simulation_bake_directory);
 
   clear_runtime_data(nmd);
 }