Simulation: Add modifier to access simulation data

For now the "Simulation" modifier only exists for point cloud objects, because
we need this for the particle system. Right now, the modifier is doing nothing.

There is a new `DEG_add_simulation_relation` function that is used
by the modifier to make sure that the simulation is evaluated before
the modifier is executed.

Reviewers: brecht, sergey

Differential Revision: https://developer.blender.org/D7549

21 files changed, 212 insertions, 1 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_modifier.py b/release/scripts/startup/bl_ui/properties_data_modifier.py
index 6f3dae9e01c..75e9a320130 100644
--- a/release/scripts/startup/bl_ui/properties_data_modifier.py
+++ b/release/scripts/startup/bl_ui/properties_data_modifier.py
@@ -1826,6 +1826,10 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
         col.prop(md, "thresh", text="Threshold")
         col.prop(md, "face_influence")
 
+    def SIMULATION(self, layout, ob, md):
+        layout.prop(md, "simulation")
+        layout.prop(md, "data_path")
+
 
 class DATA_PT_gpencil_modifiers(ModifierButtonsPanel, Panel):
     bl_label = "Modifiers"
diff --git a/source/blender/blenkernel/BKE_simulation.h b/source/blender/blenkernel/BKE_simulation.h
index aad0ada75a9..d1cf782e9e5 100644
--- a/source/blender/blenkernel/BKE_simulation.h
+++ b/source/blender/blenkernel/BKE_simulation.h
@@ -23,9 +23,12 @@ extern "C" {
 
 struct Main;
 struct Simulation;
+struct Depsgraph;
 
 void *BKE_simulation_add(struct Main *bmain, const char *name);
 
+void BKE_simulation_data_update(struct Depsgraph *depsgraph, struct Scene *scene);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/intern/simulation.cc b/source/blender/blenkernel/intern/simulation.cc
index ace91424764..b4cfa7cf0ef 100644
--- a/source/blender/blenkernel/intern/simulation.cc
+++ b/source/blender/blenkernel/intern/simulation.cc
@@ -22,6 +22,7 @@
 
 #include "DNA_ID.h"
 #include "DNA_defaults.h"
+#include "DNA_scene_types.h"
 #include "DNA_simulation_types.h"
 
 #include "BLI_compiler_compat.h"
@@ -44,6 +45,8 @@
 
 #include "BLT_translation.h"
 
+#include "DEG_depsgraph.h"
+
 static void simulation_init_data(ID *id)
 {
   Simulation *simulation = (Simulation *)id;
@@ -108,3 +111,7 @@ IDTypeInfo IDType_ID_SIM = {
     /* free_data */ simulation_free_data,
     /* make_local */ nullptr,
 };
+
+void BKE_simulation_data_update(Depsgraph *UNUSED(depsgraph), Scene *UNUSED(scene))
+{
+}
diff --git a/source/blender/depsgraph/DEG_depsgraph_build.h b/source/blender/depsgraph/DEG_depsgraph_build.h
index 19e9c5c26b1..81157102bb1 100644
--- a/source/blender/depsgraph/DEG_depsgraph_build.h
+++ b/source/blender/depsgraph/DEG_depsgraph_build.h
@@ -39,6 +39,7 @@ struct ID;
 struct Main;
 struct Object;
 struct Scene;
+struct Simulation;
 struct ViewLayer;
 struct bNodeTree;
 
@@ -153,6 +154,9 @@ void DEG_add_object_relation(struct DepsNodeHandle *node_handle,
                              struct Object *object,
                              eDepsObjectComponentType component,
                              const char *description);
+void DEG_add_simulation_relation(struct DepsNodeHandle *node_handle,
+                                 struct Simulation *simulation,
+                                 const char *description);
 void DEG_add_bone_relation(struct DepsNodeHandle *handle,
                            struct Object *object,
                            const char *bone_name,
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index cefe87d1e1f..44ddd9522e0 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -97,6 +97,7 @@
 #include "BKE_scene.h"
 #include "BKE_sequencer.h"
 #include "BKE_shader_fx.h"
+#include "BKE_simulation.h"
 #include "BKE_sound.h"
 #include "BKE_tracking.h"
 #include "BKE_volume.h"
@@ -1753,6 +1754,11 @@ void DepsgraphNodeBuilder::build_simulation(Simulation *simulation)
   add_id_node(&simulation->id);
   build_animdata(&simulation->id);
   build_parameters(&simulation->id);
+
+  add_operation_node(&simulation->id,
+                     NodeType::SIMULATION,
+                     OperationCode::SIMULATION_EVAL,
+                     function_bind(BKE_simulation_data_update, _1, get_cow_datablock(scene_)));
 }
 
 void DepsgraphNodeBuilder::build_scene_sequencer(Scene *scene)
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 6bdb7500b4a..8f977e07f17 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -2578,6 +2578,11 @@ void DepsgraphRelationBuilder::build_simulation(Simulation *simulation)
   }
   build_animdata(&simulation->id);
   build_parameters(&simulation->id);
+
+  OperationKey simulation_update_key(
+      &simulation->id, NodeType::SIMULATION, OperationCode::SIMULATION_EVAL);
+  TimeSourceKey time_src_key;
+  add_relation(time_src_key, simulation_update_key, "TimeSrc -> Simulation");
 }
 
 void DepsgraphRelationBuilder::build_scene_sequencer(Scene *scene)
diff --git a/source/blender/depsgraph/intern/debug/deg_debug_relations_graphviz.cc b/source/blender/depsgraph/intern/debug/deg_debug_relations_graphviz.cc
index bde48affc28..dbe88ee92a8 100644
--- a/source/blender/depsgraph/intern/debug/deg_debug_relations_graphviz.cc
+++ b/source/blender/depsgraph/intern/debug/deg_debug_relations_graphviz.cc
@@ -439,7 +439,8 @@ static void deg_debug_graphviz_node(const DebugContext &ctx, const Node *node)
     case NodeType::SYNCHRONIZATION:
     case NodeType::AUDIO:
     case NodeType::ARMATURE:
-    case NodeType::GENERIC_DATABLOCK: {
+    case NodeType::GENERIC_DATABLOCK:
+    case NodeType::SIMULATION: {
       ComponentNode *comp_node = (ComponentNode *)node;
       if (!comp_node->operations.empty()) {
         deg_debug_graphviz_node_cluster_begin(ctx, node);
diff --git a/source/blender/depsgraph/intern/depsgraph_build.cc b/source/blender/depsgraph/intern/depsgraph_build.cc
index 9e12d00b42f..9e50bd87d6c 100644
--- a/source/blender/depsgraph/intern/depsgraph_build.cc
+++ b/source/blender/depsgraph/intern/depsgraph_build.cc
@@ -34,6 +34,7 @@
 #include "DNA_cachefile_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_simulation_types.h"
 
 #include "BKE_main.h"
 #include "BKE_scene.h"
@@ -103,6 +104,16 @@ void DEG_add_object_relation(DepsNodeHandle *node_handle,
   deg_node_handle->builder->add_node_handle_relation(comp_key, deg_node_handle, description);
 }
 
+void DEG_add_simulation_relation(DepsNodeHandle *node_handle,
+                                 Simulation *simulation,
+                                 const char *description)
+{
+  DEG::OperationKey operation_key(
+      &simulation->id, DEG::NodeType::SIMULATION, DEG::OperationCode::SIMULATION_EVAL);
+  DEG::DepsNodeHandle *deg_node_handle = get_node_handle(node_handle);
+  deg_node_handle->builder->add_node_handle_relation(operation_key, deg_node_handle, description);
+}
+
 void DEG_add_object_cache_relation(DepsNodeHandle *node_handle,
                                    CacheFile *cache_file,
                                    eDepsObjectComponentType component,
diff --git a/source/blender/depsgraph/intern/node/deg_node.cc b/source/blender/depsgraph/intern/node/deg_node.cc
index d95e05a6f4f..10760d3170b 100644
--- a/source/blender/depsgraph/intern/node/deg_node.cc
+++ b/source/blender/depsgraph/intern/node/deg_node.cc
@@ -114,6 +114,8 @@ const char *nodeTypeAsString(NodeType type)
       return "ARMATURE";
     case NodeType::GENERIC_DATABLOCK:
       return "GENERIC_DATABLOCK";
+    case NodeType::SIMULATION:
+      return "SIMULATION";
 
     /* Total number of meaningful node types. */
     case NodeType::NUM_TYPES:
@@ -172,6 +174,7 @@ eDepsSceneComponentType nodeTypeToSceneComponent(NodeType type)
     case NodeType::SHADING:
     case NodeType::CACHE:
     case NodeType::PROXY:
+    case NodeType::SIMULATION:
       return DEG_SCENE_COMP_PARAMETERS;
   }
   BLI_assert(!"Unhandled node type, not suppsed to happen.");
@@ -245,6 +248,7 @@ eDepsObjectComponentType nodeTypeToObjectComponent(NodeType type)
     case NodeType::BATCH_CACHE:
     case NodeType::DUPLI:
     case NodeType::SYNCHRONIZATION:
+    case NodeType::SIMULATION:
     case NodeType::UNDEFINED:
     case NodeType::NUM_TYPES:
       return DEG_OB_COMP_PARAMETERS;
diff --git a/source/blender/depsgraph/intern/node/deg_node.h b/source/blender/depsgraph/intern/node/deg_node.h
index ad1eba2f7ba..f0ce38ddeae 100644
--- a/source/blender/depsgraph/intern/node/deg_node.h
+++ b/source/blender/depsgraph/intern/node/deg_node.h
@@ -127,6 +127,8 @@ enum class NodeType {
   DUPLI,
   /* Synchronization back to original datablock. */
   SYNCHRONIZATION,
+  /* Simulation component. */
+  SIMULATION,
 
   /* Total number of meaningful node types. */
   NUM_TYPES,
diff --git a/source/blender/depsgraph/intern/node/deg_node_component.cc b/source/blender/depsgraph/intern/node/deg_node_component.cc
index e2c1f74ec46..f4d042fecf9 100644
--- a/source/blender/depsgraph/intern/node/deg_node_component.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_component.cc
@@ -333,6 +333,7 @@ DEG_COMPONENT_NODE_DEFINE(Synchronization, SYNCHRONIZATION, 0);
 DEG_COMPONENT_NODE_DEFINE(Audio, AUDIO, 0);
 DEG_COMPONENT_NODE_DEFINE(Armature, ARMATURE, 0);
 DEG_COMPONENT_NODE_DEFINE(GenericDatablock, GENERIC_DATABLOCK, 0);
+DEG_COMPONENT_NODE_DEFINE(Simulation, SIMULATION, 0);
 
 /* Node Types Register =================================== */
 
@@ -362,6 +363,7 @@ void deg_register_component_depsnodes()
   register_node_typeinfo(&DNTI_AUDIO);
   register_node_typeinfo(&DNTI_ARMATURE);
   register_node_typeinfo(&DNTI_GENERIC_DATABLOCK);
+  register_node_typeinfo(&DNTI_SIMULATION);
 }
 
 }  // namespace DEG
diff --git a/source/blender/depsgraph/intern/node/deg_node_component.h b/source/blender/depsgraph/intern/node/deg_node_component.h
index 41d5c130ffd..ca37401d200 100644
--- a/source/blender/depsgraph/intern/node/deg_node_component.h
+++ b/source/blender/depsgraph/intern/node/deg_node_component.h
@@ -191,6 +191,7 @@ DEG_COMPONENT_NODE_DECLARE_GENERIC(Synchronization);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(Audio);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(Armature);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(GenericDatablock);
+DEG_COMPONENT_NODE_DECLARE_GENERIC(Simulation);
 
 /* Bone Component */
 struct BoneComponentNode : public ComponentNode {
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.cc b/source/blender/depsgraph/intern/node/deg_node_operation.cc
index d327e1da8a1..2381076161f 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.cc
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.cc
@@ -194,6 +194,8 @@ const char *operationCodeAsString(OperationCode opcode)
     /* instancing/duplication. */
     case OperationCode::DUPLI:
       return "DUPLI";
+    case OperationCode::SIMULATION_EVAL:
+      return "SIMULATION_EVAL";
   }
   BLI_assert(!"Unhandled operation code, should never happen.");
   return "UNKNOWN";
diff --git a/source/blender/depsgraph/intern/node/deg_node_operation.h b/source/blender/depsgraph/intern/node/deg_node_operation.h
index 2faf139ec93..865a25d2124 100644
--- a/source/blender/depsgraph/intern/node/deg_node_operation.h
+++ b/source/blender/depsgraph/intern/node/deg_node_operation.h
@@ -198,6 +198,9 @@ enum class OperationCode {
 
   /* Duplication/instancing system. --------------------------------------- */
   DUPLI,
+
+  /* Simulation. ---------------------------------------------------------- */
+  SIMULATION_EVAL,
 };
 const char *operationCodeAsString(OperationCode opcode);
 
diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 6eba41982a7..13cbda5aad7 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -2191,6 +2191,9 @@ TreeElementIcon tree_element_get_icon(TreeStoreElem *tselem, TreeElement *te)
             case eModifierType_WeightedNormal:
               data.icon = ICON_MOD_NORMALEDIT;
               break;
+            case eModifierType_Simulation:
+              data.icon = ICON_PHYSICS; /* TODO: Use correct icon. */
+              break;
               /* Default */
             case eModifierType_None:
             case eModifierType_ShapeKey:
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 9c72bd02c2b..972ef197954 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -94,6 +94,7 @@ typedef enum ModifierType {
   eModifierType_WeightedNormal = 54,
   eModifierType_Weld = 55,
   eModifierType_Fluid = 56,
+  eModifierType_Simulation = 57,
   NUM_MODIFIER_TYPES,
 } ModifierType;
 
@@ -2118,6 +2119,13 @@ enum {
 #define MOD_MESHSEQ_READ_ALL \
   (MOD_MESHSEQ_READ_VERT | MOD_MESHSEQ_READ_POLY | MOD_MESHSEQ_READ_UV | MOD_MESHSEQ_READ_COLOR)
 
+typedef struct SimulationModifierData {
+  ModifierData modifier;
+
+  struct Simulation *simulation;
+  char data_path[64];
+} SimulationModifierData;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 638268adff7..48e3c47208f 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -289,6 +289,13 @@ const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
      "Spawn particles from the shape"},
     {eModifierType_Softbody, "SOFT_BODY", ICON_MOD_SOFT, "Soft Body", ""},
     {eModifierType_Surface, "SURFACE", ICON_MODIFIER, "Surface", ""},
+#ifdef WITH_NEW_SIMULATION_TYPE
+    {eModifierType_Simulation,
+     "SIMULATION",
+     ICON_PHYSICS,
+     "Simulation",
+     ""}, /* TODO: Use correct icon. */
+#endif
     {0, NULL, 0, NULL, NULL},
 };
 
@@ -716,6 +723,8 @@ static StructRNA *rna_Modifier_refine(struct PointerRNA *ptr)
       return &RNA_SurfaceDeformModifier;
     case eModifierType_WeightedNormal:
       return &RNA_WeightedNormalModifier;
+    case eModifierType_Simulation:
+      return &RNA_SimulationModifier;
     /* Default */
     case eModifierType_Fluidsim: /* deprecated */
     case eModifierType_None:
@@ -6552,6 +6561,29 @@ static void rna_def_modifier_weightednormal(BlenderRNA *brna)
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 }
 
+static void rna_def_modifier_simulation_access(BlenderRNA *brna)
+{
+  StructRNA *srna;
+  PropertyRNA *prop;
+
+  srna = RNA_def_struct(brna, "SimulationModifier", "Modifier");
+  RNA_def_struct_ui_text(srna, "Simulation Modifier", "");
+  RNA_def_struct_sdna(srna, "SimulationModifierData");
+  RNA_def_struct_ui_icon(srna, ICON_PHYSICS); /* TODO: Use correct icon. */
+
+#  ifdef WITH_NEW_SIMULATION_TYPE
+  prop = RNA_def_property(srna, "simulation", PROP_POINTER, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Simulation", "Simulation to access");
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
+#  endif
+
+  prop = RNA_def_property(srna, "data_path", PROP_STRING, PROP_NONE);
+  RNA_def_property_ui_text(
+      prop, "Data Path", "Identifier of the simulation component that should be accessed");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+}
+
 void RNA_def_modifier(BlenderRNA *brna)
 {
   StructRNA *srna;
@@ -6677,6 +6709,7 @@ void RNA_def_modifier(BlenderRNA *brna)
   rna_def_modifier_meshseqcache(brna);
   rna_def_modifier_surfacedeform(brna);
   rna_def_modifier_weightednormal(brna);
+  rna_def_modifier_simulation_access(brna);
 }
 
 #endif
diff --git a/source/blender/modifiers/CMakeLists.txt b/source/blender/modifiers/CMakeLists.txt
index 48acbdc17f3..8ab7d35070b 100644
--- a/source/blender/modifiers/CMakeLists.txt
+++ b/source/blender/modifiers/CMakeLists.txt
@@ -78,6 +78,7 @@ set(SRC
   intern/MOD_shapekey.c
   intern/MOD_shrinkwrap.c
   intern/MOD_simpledeform.c
+  intern/MOD_simulation.cc
   intern/MOD_skin.c
   intern/MOD_smooth.c
   intern/MOD_softbody.c
diff --git a/source/blender/modifiers/MOD_modifiertypes.h b/source/blender/modifiers/MOD_modifiertypes.h
index 5dc4adf4393..ba676bbe459 100644
--- a/source/blender/modifiers/MOD_modifiertypes.h
+++ b/source/blender/modifiers/MOD_modifiertypes.h
@@ -86,6 +86,7 @@ extern ModifierTypeInfo modifierType_CorrectiveSmooth;
 extern ModifierTypeInfo modifierType_MeshSequenceCache;
 extern ModifierTypeInfo modifierType_SurfaceDeform;
 extern ModifierTypeInfo modifierType_WeightedNormal;
+extern ModifierTypeInfo modifierType_Simulation;
 
 /* MOD_util.c */
 void modifier_type_init(ModifierTypeInfo *types[]);
diff --git a/source/blender/modifiers/intern/MOD_simulation.cc b/source/blender/modifiers/intern/MOD_simulation.cc
new file mode 100644
index 00000000000..f52daf53186
--- /dev/null
+++ b/source/blender/modifiers/intern/MOD_simulation.cc
@@ -0,0 +1,109 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2005 by the Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup modifiers
+ */
+
+#include <iostream>
+#include <string>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_utildefines.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+#include "DNA_modifier_types.h"
+#include "DNA_object_types.h"
+#include "DNA_pointcloud_types.h"
+#include "DNA_scene_types.h"
+#include "DNA_simulation_types.h"
+
+#include "BKE_customdata.h"
+#include "BKE_lib_query.h"
+#include "BKE_mesh.h"
+#include "BKE_modifier.h"
+
+#include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
+
+#include "MOD_modifiertypes.h"
+
+static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
+{
+  SimulationModifierData *smd = (SimulationModifierData *)md;
+  if (smd->simulation) {
+    DEG_add_simulation_relation(ctx->node, smd->simulation, "Accessed Simulation");
+  }
+}
+
+static void foreachIDLink(ModifierData *md, Object *ob, IDWalkFunc walk, void *userData)
+{
+  SimulationModifierData *smd = (SimulationModifierData *)md;
+  walk(userData, ob, (ID **)&smd->simulation, IDWALK_CB_USER);
+}
+
+static bool isDisabled(const struct Scene *UNUSED(scene),
+                       ModifierData *md,
+                       bool UNUSED(useRenderParams))
+{
+  SimulationModifierData *smd = (SimulationModifierData *)md;
+  return smd->simulation == nullptr;
+}
+
+static PointCloud *modifyPointCloud(ModifierData *md,
+                                    const ModifierEvalContext *UNUSED(ctx),
+                                    PointCloud *pointcloud)
+{
+  SimulationModifierData *smd = (SimulationModifierData *)md;
+  UNUSED_VARS(smd);
+  return pointcloud;
+}
+
+ModifierTypeInfo modifierType_Simulation = {
+    /* name */ "Simulation",
+    /* structName */ "SimulationModifierData",
+    /* structSize */ sizeof(SimulationModifierData),
+    /* type */ eModifierTypeType_None,
+    /* flags */ (ModifierTypeFlag)0,
+
+    /* copyData */ BKE_modifier_copydata_generic,
+
+    /* deformVerts */ NULL,
+    /* deformMatrices */ NULL,
+    /* deformVertsEM */ NULL,
+    /* deformMatricesEM */ NULL,
+    /* modifyMesh */ NULL,
+    /* modifyHair */ NULL,
+    /* modifyPointCloud */ modifyPointCloud,
+    /* modifyVolume */ NULL,
+
+    /* initData */ NULL,
+    /* requiredDataMask */ NULL,
+    /* freeData */ NULL,
+    /* isDisabled */ isDisabled,
+    /* updateDepsgraph */ updateDepsgraph,
+    /* dependsOnTime */ NULL,
+    /* dependsOnNormals */ NULL,
+    /* foreachObjectLink */ NULL,
+    /* foreachIDLink */ foreachIDLink,
+    /* foreachTexLink */ NULL,
+    /* freeRuntimeData */ NULL,
+};
diff --git a/source/blender/modifiers/intern/MOD_util.c b/source/blender/modifiers/intern/MOD_util.c
index f6b7c829c13..bd453c24a31 100644
--- a/source/blender/modifiers/intern/MOD_util.c
+++ b/source/blender/modifiers/intern/MOD_util.c
@@ -337,5 +337,6 @@ void modifier_type_init(ModifierTypeInfo *types[])
   INIT_TYPE(MeshSequenceCache);
   INIT_TYPE(SurfaceDeform);
   INIT_TYPE(WeightedNormal);
+  INIT_TYPE(Simulation);
 #undef INIT_TYPE
 }