Added support of saving and loading of embedded blend tree resources.

src/AnimGraph/AnimGraphBlendTreeResource.h

@@ -21,7 +21,7 @@ struct AnimNode;
 
 struct AnimNodeResource {
   std::string m_name;
-  std::string m_type_name;
+  std::string m_node_type_name;
   AnimNode* m_anim_node = nullptr;
   NodeDescriptorBase* m_socket_accessor = nullptr;
   float m_position[2] = {0.f, 0.f};

src/AnimGraph/AnimGraphEditor.cc

@@ -162,7 +162,7 @@ void SkinnedMeshWidget(SkinnedMesh* skinned_mesh) {
 void AnimGraphEditorRenderSidebar(
     AnimGraphBlendTreeResource& graph_resource,
     AnimNodeResource& node_resource) {
-  ImGui::Text("[%s]", node_resource.m_type_name.c_str());
+  ImGui::Text("[%s]", node_resource.m_node_type_name.c_str());
 
   char node_name_buffer[256];
   memset(node_name_buffer, 0, sizeof(node_name_buffer));
@@ -307,7 +307,7 @@ void AnimGraphEditorUpdate(ax::NodeEditor::EditorContext* context) {
           ImVec2(node_resource.m_position[0], node_resource.m_position[1]));
     }
     ax::NodeEditor::BeginNode(node_id);
-    ImGui::Text("%s", node_resource.m_type_name.c_str());
+    ImGui::Text("%s", node_resource.m_node_type_name.c_str());
 
     // Inputs
     std::vector<Socket>& node_inputs =
@@ -485,7 +485,7 @@ void LegacyAnimGraphEditorUpdate() {
     } else if (&node_resource == &sGraphGresource.getGraphInputNode()) {
       ImGui::TextUnformatted("Graph Inputs");
     } else {
-      ImGui::TextUnformatted(node_resource.m_type_name.c_str());
+      ImGui::TextUnformatted(node_resource.m_node_type_name.c_str());
     }
     ImNodes::EndNodeTitleBar();
 

src/AnimGraph/AnimGraphNodes.h

@@ -262,6 +262,8 @@ static inline AnimNode* AnimNodeFactory(const std::string& name) {
     result = new LockTranslationNode;
   } else if (name == "BlendTree") {
     result = new BlendTreeNode;
+  } else if (name == "BlendTreeSockets") {
+    result = new BlendTreeNode;
   } else if (name == "MathAddNode") {
     result = new MathAddNode;
   } else if (name == "MathFloatToVec3Node") {
@@ -292,6 +294,8 @@ static inline NodeDescriptorBase* AnimNodeDescriptorFactory(
     return CreateNodeDescriptor<LockTranslationNode>(node);
   } else if (node_type_name == "BlendTree") {
     return CreateNodeDescriptor<BlendTreeNode>(node);
+  } else if (node_type_name == "BlendTreeSockets") {
+    return CreateNodeDescriptor<BlendTreeNode>(node);
   } else if (node_type_name == "MathAddNode") {
     return CreateNodeDescriptor<MathAddNode>(node);
   } else if (node_type_name == "MathFloatToVec3Node") {

src/AnimGraph/AnimGraphResource.cc

@@ -14,6 +14,10 @@
 
 using json = nlohmann::json;
 
+// forward declarations
+static json sAnimGraphResourceBlendTreeToJson(const AnimGraphResource& anim_graph_resource);
+static bool sAnimGraphResourceBlendTreeFromJson(const json& json_data, AnimGraphResource* result_graph_resource);
+
 //
 // Socket <-> json
 //
@@ -125,20 +129,24 @@ Socket sJsonToSocket(const json& json_data) {
 // AnimGraphNode <-> json
 //
 json sAnimGraphNodeToJson(
-    const AnimNodeResource& node,
+    const AnimNodeResource* node,
     size_t node_index,
     const std::vector<BlendTreeConnectionResource>& connections) {
   json result;
 
-  result["name"] = node.m_name;
+  result["name"] = node->m_name;
   result["type"] = "AnimNodeResource";
-  result["node_type"] = node.m_type_name;
+  result["node_type"] = node->m_node_type_name;
 
   for (size_t j = 0; j < 2; j++) {
-    result["position"][j] = node.m_position[j];
+    result["position"][j] = node->m_position[j];
   }
 
-  for (const auto& socket : node.m_socket_accessor->m_inputs) {
+  if (node->m_node_type_name == "BlendTree") {
+
+  }
+
+  for (const auto& socket : node->m_socket_accessor->m_inputs) {
     if (socket.m_type == SocketType::SocketTypeAnimation) {
       continue;
     }
@@ -157,28 +165,37 @@ json sAnimGraphNodeToJson(
     }
   }
 
-  for (auto& property : node.m_socket_accessor->m_properties) {
+  for (auto& property : node->m_socket_accessor->m_properties) {
     result["properties"][property.m_name] = sSocketToJson(property);
   }
 
   return result;
 }
 
-AnimNodeResource sAnimGraphNodeFromJson(
+AnimNodeResource* sAnimGraphNodeFromJson(
     const json& json_node,
     size_t node_index) {
-  AnimNodeResource result;
 
-  result.m_name = json_node["name"];
+  std::string node_type = json_node["node_type"];
-  result.m_type_name = json_node["node_type"];
-  result.m_position[0] = json_node["position"][0];
-  result.m_position[1] = json_node["position"][1];
 
-  result.m_anim_node = AnimNodeFactory(result.m_type_name);
+  if (node_type == "BlendTree") {
-  result.m_socket_accessor =
+    AnimGraphResource* result = new AnimGraphResource();
-      AnimNodeDescriptorFactory(result.m_type_name, result.m_anim_node);
+    sAnimGraphResourceBlendTreeFromJson(json_node, result);
+    return result;
+  }
 
-  for (auto& property : result.m_socket_accessor->m_properties) {
+  AnimNodeResource* result;
+  result = new AnimNodeResource();
+  result->m_name = json_node["name"];
+  result->m_node_type_name = node_type;
+  result->m_position[0] = json_node["position"][0];
+  result->m_position[1] = json_node["position"][1];
+
+  result->m_anim_node = AnimNodeFactory(result->m_node_type_name);
+  result->m_socket_accessor =
+      AnimNodeDescriptorFactory(result->m_node_type_name, result->m_anim_node);
+
+  for (auto& property : result->m_socket_accessor->m_properties) {
     property = sJsonToSocket(json_node["properties"][property.m_name]);
   }
 
@@ -187,10 +204,10 @@ AnimNodeResource sAnimGraphNodeFromJson(
       assert(json_node["inputs"][j].contains("name"));
       std::string input_name = json_node["inputs"][j]["name"];
       Socket* input_socket =
-          result.m_socket_accessor->GetInputSocket(input_name.c_str());
+          result->m_socket_accessor->GetInputSocket(input_name.c_str());
       if (input_socket == nullptr) {
         std::cerr << "Could not find input socket with name " << input_name
-                  << " for node type " << result.m_type_name << std::endl;
+                  << " for node type " << result->m_node_type_name << std::endl;
         abort();
       }
       *input_socket = sJsonToSocket(json_node["inputs"][j]);
@@ -230,6 +247,160 @@ BlendTreeConnectionResource sAnimGraphConnectionFromJson(
   return connection;
 }
 
+static json sAnimGraphResourceBlendTreeToJson(const AnimGraphResource& anim_graph_resource) {
+  json result;
+
+  result["name"] = anim_graph_resource.m_name;
+  result["type"] = "AnimNodeResource";
+  result["node_type"] = "BlendTree";
+
+  const BlendTreeResource& blend_tree_resource = anim_graph_resource.m_blend_tree_resource;
+
+  for (size_t i = 0; i < blend_tree_resource.m_nodes.size(); i++) {
+    const AnimNodeResource* node = blend_tree_resource.m_nodes[i];
+
+    if (node->m_node_type_name == "BlendTree") {
+      const AnimGraphResource* graph_resource = dynamic_cast<const AnimGraphResource*>(node);
+      result["nodes"][i] = sAnimGraphResourceBlendTreeToJson(*graph_resource);
+    } else {
+      result["nodes"][i] =
+          sAnimGraphNodeToJson(node, i, blend_tree_resource.m_connections);
+    }
+  }
+
+  for (size_t i = 0; i < blend_tree_resource.m_connections.size(); i++) {
+    const BlendTreeConnectionResource& connection =
+        blend_tree_resource.m_connections[i];
+    result["connections"][i] = sAnimGraphConnectionToJson(connection);
+  }
+
+  // Graph inputs and outputs
+  {
+    const AnimNodeResource* graph_output_node =
+        blend_tree_resource.m_nodes[0];
+    const std::vector<Socket> graph_inputs =
+        graph_output_node->m_socket_accessor->m_inputs;
+    for (size_t i = 0; i < graph_inputs.size(); i++) {
+      result["nodes"][0]["inputs"][i] = sSocketToJson(graph_inputs[i]);
+    }
+
+    const AnimNodeResource* graph_input_node = blend_tree_resource.m_nodes[1];
+    const std::vector<Socket> graph_outputs =
+        graph_input_node->m_socket_accessor->m_outputs;
+    for (size_t i = 0; i < graph_outputs.size(); i++) {
+      result["nodes"][1]["outputs"][i] = sSocketToJson(graph_outputs[i]);
+    }
+  }
+  return result;
+}
+
+static bool sAnimGraphResourceBlendTreeFromJson(const json& json_data, AnimGraphResource* result_graph_resource) {
+  BlendTreeResource& blend_tree_resource = result_graph_resource->m_blend_tree_resource;
+
+  result_graph_resource->m_graph_type_name = "BlendTree";
+  result_graph_resource->m_node_type_name = "BlendTree";
+  result_graph_resource->m_name = json_data["name"];
+
+  // Load nodes
+  for (size_t i = 0, n = json_data["nodes"].size(); i < n; i++) {
+    const json& json_node = json_data["nodes"][i];
+    if (json_node["type"] != "AnimNodeResource") {
+      std::cerr
+          << "Invalid json object. Expected type 'AnimNodeResource' but got '"
+          << json_node["type"] << "'." << std::endl;
+      return false;
+    }
+
+    AnimNodeResource* node = sAnimGraphNodeFromJson(json_node, i);
+    blend_tree_resource.m_nodes.push_back(node);
+  }
+
+  // Graph outputs
+  const json& graph_outputs = json_data["nodes"][0]["inputs"];
+  for (const auto& graph_output : graph_outputs) {
+    AnimNodeResource* graph_node = blend_tree_resource.m_nodes[0];
+    graph_node->m_socket_accessor->m_inputs.push_back(
+        sJsonToSocket(graph_output));
+  }
+
+  // Graph inputs (optional)
+  if (json_data["nodes"][1].contains("outputs")) {
+    const json& graph_inputs = json_data["nodes"][1]["outputs"];
+    for (const auto& graph_input : graph_inputs) {
+      AnimNodeResource* graph_node = blend_tree_resource.m_nodes[1];
+      graph_node->m_socket_accessor->m_outputs.push_back(
+          sJsonToSocket(graph_input));
+    }
+  }
+
+  // Load connections
+  for (const auto& json_connection : json_data["connections"]) {
+    if (json_connection["type"] != "AnimGraphConnectionResource") {
+      std::cerr << "Invalid json object. Expected type "
+                   "'AnimGraphConnectionResource' "
+                   "but got '"
+                << json_connection["type"] << "'." << std::endl;
+      return false;
+    }
+
+    BlendTreeConnectionResource connection =
+        sAnimGraphConnectionFromJson(json_connection);
+    blend_tree_resource.m_connections.push_back(connection);
+  }
+
+  return true;
+}
+
+bool BlendTreeResource::ConnectSockets (
+    const AnimNodeResource* source_node,
+    const std::string& source_socket_name,
+    const AnimNodeResource* target_node,
+    const std::string& target_socket_name) {
+  size_t source_node_index = GetNodeIndex(source_node);
+  size_t target_node_index = GetNodeIndex(target_node);
+  
+  if (source_node_index >= m_nodes.size()
+      || target_node_index >= m_nodes.size()) {
+    std::cerr << "Cannot connect nodes: could not find nodes." << std::endl;
+    return false;
+  }
+
+  Socket* source_socket;
+  Socket* target_socket;
+
+  if (target_node->m_node_type_name == "BlendTree") {
+    const AnimGraphResource* target_graph_resource = dynamic_cast<const AnimGraphResource*>(target_node);
+    AnimNodeResource* graph_output_node = target_graph_resource->m_blend_tree_resource.GetGraphInputNode();
+    target_socket = graph_output_node->m_socket_accessor->GetOutputSocket(target_socket_name.c_str());
+  } else {
+    target_socket =
+        target_node->m_socket_accessor->GetInputSocket(target_socket_name.c_str());
+  }
+
+  if (source_node->m_node_type_name == "BlendTree") {
+    const AnimGraphResource* source_graph_resource = dynamic_cast<const AnimGraphResource*>(source_node);
+    AnimNodeResource* graph_output_node = source_graph_resource->m_blend_tree_resource.GetGraphOutputNode();
+    source_socket = graph_output_node->m_socket_accessor->GetInputSocket(source_socket_name.c_str());
+  } else {
+    source_socket =
+        source_node->m_socket_accessor->GetOutputSocket(source_socket_name.c_str());
+  }
+  
+  if (source_socket == nullptr || target_socket == nullptr) {
+    std::cerr << "Cannot connect nodes: could not find sockets." << std::endl;
+    return false;
+  }
+
+  BlendTreeConnectionResource connection;
+  connection.source_node_index = source_node_index;
+  connection.source_socket_name = source_socket_name;
+  connection.target_node_index = target_node_index;
+  connection.target_socket_name = target_socket_name;
+  m_connections.push_back(connection);
+
+  return true;
+}
+
 bool AnimGraphResource::LoadFromFile(const char* filename) {
   std::ifstream input_file;
   input_file.open(filename);
@@ -253,7 +424,7 @@ bool AnimGraphResource::LoadFromFile(const char* filename) {
   }
 
   if (json_data["node_type"] == "BlendTree") {
-    return LoadBlendTreeResourceFromJson(json_data);
+    return sAnimGraphResourceBlendTreeFromJson(json_data, this);
   } else if (json_data["node_type"] == "StateMachine") {
     return LoadStateMachineResourceFromJson(json_data);
   }
@@ -265,69 +436,14 @@ bool AnimGraphResource::LoadFromFile(const char* filename) {
   return false;
 }
 
-bool AnimGraphResource::LoadBlendTreeResourceFromJson(nlohmann::json const& json_data) {
-  m_blend_tree_resource.Reset();
-  m_type = "BlendTree";
-  m_name = json_data["name"];
-
-  // Load nodes
-  for (size_t i = 0, n = json_data["nodes"].size(); i < n; i++) {
-    const json& json_node = json_data["nodes"][i];
-    if (json_node["type"] != "AnimNodeResource") {
-      std::cerr
-          << "Invalid json object. Expected type 'AnimNodeResource' but got '"
-          << json_node["type"] << "'." << std::endl;
-      return false;
-    }
-
-    AnimNodeResource node = sAnimGraphNodeFromJson(json_node, i);
-    m_blend_tree_resource.m_nodes.push_back(node);
-  }
-
-  // Graph outputs
-  const json& graph_outputs = json_data["nodes"][0]["inputs"];
-  for (const auto& graph_output : graph_outputs) {
-    AnimNodeResource& graph_node = m_blend_tree_resource.m_nodes[0];
-    graph_node.m_socket_accessor->m_inputs.push_back(
-        sJsonToSocket(graph_output));
-  }
-
-  // Graph inputs (optional)
-  if (json_data["nodes"][1].contains("outputs")) {
-      const json& graph_inputs = json_data["nodes"][1]["outputs"];
-      for (const auto& graph_input : graph_inputs) {
-        AnimNodeResource& graph_node = m_blend_tree_resource.m_nodes[1];
-        graph_node.m_socket_accessor->m_outputs.push_back(
-            sJsonToSocket(graph_input));
-      }
-    }
-
-  // Load connections
-  for (const auto& json_connection : json_data["connections"]) {
-    if (json_connection["type"] != "AnimGraphConnectionResource") {
-      std::cerr << "Invalid json object. Expected type "
-                   "'AnimGraphConnectionResource' "
-                   "but got '"
-                << json_connection["type"] << "'." << std::endl;
-      return false;
-    }
-
-    BlendTreeConnectionResource connection =
-        sAnimGraphConnectionFromJson(json_connection);
-    m_blend_tree_resource.m_connections.push_back(connection);
-  }
-
-  return true;
-}
-
 bool AnimGraphResource::SaveToFile(const char* filename) const {
-  if (m_type == "BlendTree") {
+  if (m_graph_type_name == "BlendTree") {
     return SaveBlendTreeResourceToFile(filename);
-  } else if (m_type == "StateMachine") {
+  } else if (m_graph_type_name == "StateMachine") {
     return SaveStateMachineResourceToFile(filename);
   }
 
-  std::cerr << "Invalid AnimGraphResource type: " << m_type << "." << std::endl;
+  std::cerr << "Invalid AnimGraphResource type: " << m_graph_type_name << "." << std::endl;
 
   return false;
 }
@@ -336,39 +452,8 @@ bool AnimGraphResource::SaveBlendTreeResourceToFile(
     const char* filename) const {
   json result;
 
-  result["name"] = m_name;
+  result = sAnimGraphResourceBlendTreeToJson(
-  result["type"] = "AnimNodeResource";
+      *this);
-  result["node_type"] = "BlendTree";
-
-  for (size_t i = 0; i < m_blend_tree_resource.m_nodes.size(); i++) {
-    const AnimNodeResource& node = m_blend_tree_resource.m_nodes[i];
-    result["nodes"][i] =
-        sAnimGraphNodeToJson(node, i, m_blend_tree_resource.m_connections);
-  }
-
-  for (size_t i = 0; i < m_blend_tree_resource.m_connections.size(); i++) {
-    const BlendTreeConnectionResource& connection =
-        m_blend_tree_resource.m_connections[i];
-    result["connections"][i] = sAnimGraphConnectionToJson(connection);
-  }
-
-  // Graph inputs and outputs
-  {
-    const AnimNodeResource& graph_output_node =
-        m_blend_tree_resource.m_nodes[0];
-    const std::vector<Socket> graph_inputs =
-        graph_output_node.m_socket_accessor->m_inputs;
-    for (size_t i = 0; i < graph_inputs.size(); i++) {
-      result["nodes"][0]["inputs"][i] = sSocketToJson(graph_inputs[i]);
-    }
-
-    const AnimNodeResource& graph_input_node = m_blend_tree_resource.m_nodes[1];
-    const std::vector<Socket> graph_outputs =
-        graph_input_node.m_socket_accessor->m_outputs;
-    for (size_t i = 0; i < graph_outputs.size(); i++) {
-      result["nodes"][1]["outputs"][i] = sSocketToJson(graph_outputs[i]);
-    }
-  }
 
   std::ofstream output_file;
   output_file.open(filename);
@@ -380,9 +465,9 @@ bool AnimGraphResource::SaveBlendTreeResourceToFile(
 
 void AnimGraphResource::CreateBlendTreeInstance(
     AnimGraphBlendTree& result) const {
-  if (m_type != "BlendTree") {
+  if (m_node_type_name != "BlendTree") {
     std::cerr << "Invalid AnimGraphResource. Expected type 'BlendTree' but got '"
-    << m_type << "'." << std::endl;
+    << m_graph_type_name << "'." << std::endl;
     return;
   }
 
@@ -396,11 +481,10 @@ void AnimGraphResource::CreateBlendTreeInstance(
 
 void AnimGraphResource::CreateBlendTreeRuntimeNodeInstances(
     AnimGraphBlendTree& result) const {
-  for (int i = 0; i < m_blend_tree_resource.m_nodes.size(); i++) {
+  for (auto node_resource : m_blend_tree_resource.m_nodes) {
-    const AnimNodeResource& node_resource = m_blend_tree_resource.m_nodes[i];
+    AnimNode* node = AnimNodeFactory(node_resource->m_node_type_name);
-    AnimNode* node = AnimNodeFactory(node_resource.m_type_name);
+    node->m_name = node_resource->m_name;
-    node->m_name = node_resource.m_name;
+    node->m_node_type_name = node_resource->m_node_type_name;
-    node->m_node_type_name = node_resource.m_type_name;
     result.m_nodes.push_back(node);
 
     // runtime node connections
@@ -414,9 +498,9 @@ void AnimGraphResource::PrepareBlendTreeIOData(
   instance.m_node_descriptor =
       AnimNodeDescriptorFactory("BlendTree", instance.m_nodes[0]);
   instance.m_node_descriptor->m_outputs =
-      m_blend_tree_resource.m_nodes[1].m_socket_accessor->m_outputs;
+      m_blend_tree_resource.m_nodes[1]->m_socket_accessor->m_outputs;
   instance.m_node_descriptor->m_inputs =
-      m_blend_tree_resource.m_nodes[0].m_socket_accessor->m_inputs;
+      m_blend_tree_resource.m_nodes[0]->m_socket_accessor->m_inputs;
 
   //
   // graph inputs
@@ -466,9 +550,9 @@ void AnimGraphResource::PrepareBlendTreeIOData(
   // TODO: instead of every connection, only create data blocks for the source sockets and make sure every source socket gets allocated once.
   size_t connection_data_storage_size = 0;
   for (const auto& connection : m_blend_tree_resource.m_connections) {
-    const AnimNodeResource& source_node =
+    const AnimNodeResource* source_node =
         m_blend_tree_resource.m_nodes[connection.source_node_index];
-    Socket* source_socket = source_node.m_socket_accessor->GetOutputSocket(
+    Socket* source_socket = source_node->m_socket_accessor->GetOutputSocket(
         connection.source_socket_name.c_str());
     connection_data_storage_size += source_socket->m_type_size;
   }
@@ -483,7 +567,7 @@ void AnimGraphResource::PrepareBlendTreeIOData(
       nullptr);
   for (int i = 0; i < m_blend_tree_resource.m_nodes.size(); i++) {
     instance_node_descriptors[i] = AnimNodeDescriptorFactory(
-        m_blend_tree_resource.m_nodes[i].m_type_name,
+        m_blend_tree_resource.m_nodes[i]->m_node_type_name,
         instance.m_nodes[i]);
   }
 
@@ -579,13 +663,13 @@ void AnimGraphResource::PrepareBlendTreeIOData(
 void AnimGraphResource::SetRuntimeNodeProperties(
     AnimGraphBlendTree& result) const {
   for (int i = 2; i < m_blend_tree_resource.m_nodes.size(); i++) {
-    const AnimNodeResource& node_resource = m_blend_tree_resource.m_nodes[i];
+    const AnimNodeResource* node_resource = m_blend_tree_resource.m_nodes[i];
 
     NodeDescriptorBase* node_instance_accessor =
-        AnimNodeDescriptorFactory(node_resource.m_type_name, result.m_nodes[i]);
+        AnimNodeDescriptorFactory(node_resource->m_node_type_name, result.m_nodes[i]);
 
     std::vector<Socket>& resource_properties =
-        node_resource.m_socket_accessor->m_properties;
+        node_resource->m_socket_accessor->m_properties;
     for (const auto& property : resource_properties) {
       const std::string& name = property.m_name;
 

src/AnimGraph/AnimGraphResource.h

@@ -14,22 +14,16 @@ struct AnimGraphBlendTree;
 struct AnimGraphStateMachine;
 
 struct AnimNodeResource {
+  virtual ~AnimNodeResource() = default;
+
   std::string m_name;
-  std::string m_type_name;
+  std::string m_node_type_name;
   AnimNode* m_anim_node = nullptr;
   NodeDescriptorBase* m_socket_accessor = nullptr;
   float m_position[2] = {0.f, 0.f};
 };
 
-static inline AnimNodeResource AnimNodeResourceFactory(
+static inline AnimNodeResource* AnimNodeResourceFactory(const std::string& node_type_name);
-    const std::string& node_type_name) {
-  AnimNodeResource result;
-  result.m_type_name = node_type_name;
-  result.m_anim_node = AnimNodeFactory(node_type_name);
-  result.m_socket_accessor =
-      AnimNodeDescriptorFactory(node_type_name, result.m_anim_node);
-  return result;
-}
 
 struct BlendTreeConnectionResource {
   size_t source_node_index = -1;
@@ -39,7 +33,7 @@ struct BlendTreeConnectionResource {
 };
 
 struct BlendTreeResource {
-  std::vector<AnimNodeResource> m_nodes;
+  std::vector<AnimNodeResource*> m_nodes;
   std::vector<BlendTreeConnectionResource> m_connections;
 
   ~BlendTreeResource() { CleanupNodes();
@@ -52,27 +46,28 @@ struct BlendTreeResource {
   }
 
   void CleanupNodes() {
-    for (AnimNodeResource& node_resource : m_nodes) {
+    for (AnimNodeResource* node_resource : m_nodes) {
-      delete node_resource.m_anim_node;
+      delete node_resource->m_anim_node;
-      delete node_resource.m_socket_accessor;
+      delete node_resource->m_socket_accessor;
+      delete node_resource;
     }
 
     m_nodes.clear();
   }
 
   void InitGraphConnectors() {
-    m_nodes.push_back(AnimNodeResourceFactory("BlendTree"));
+    m_nodes.push_back(AnimNodeResourceFactory("BlendTreeSockets"));
-    m_nodes[0].m_name = "Outputs";
+    m_nodes[0]->m_name = "Outputs";
-    m_nodes.push_back(AnimNodeResourceFactory("BlendTree"));
+    m_nodes.push_back(AnimNodeResourceFactory("BlendTreeSockets"));
-    m_nodes[1].m_name = "Inputs";
+    m_nodes[1]->m_name = "Inputs";
   }
 
-  AnimNodeResource& GetGraphOutputNode() { return m_nodes[0]; }
+  [[nodiscard]] AnimNodeResource* GetGraphOutputNode() const { return m_nodes[0]; }
-  AnimNodeResource& GetGraphInputNode() { return m_nodes[1]; }
+  [[nodiscard]] AnimNodeResource* GetGraphInputNode() const { return m_nodes[1]; }
 
-  size_t GetNodeIndex(const AnimNodeResource& node_resource) const {
+  size_t GetNodeIndex(const AnimNodeResource* node_resource) const {
     for (size_t i = 0, n = m_nodes.size(); i < n; i++) {
-      if (&m_nodes[i] == &node_resource) {
+      if (m_nodes[i] == node_resource) {
         return i;
       }
     }
@@ -81,38 +76,10 @@ struct BlendTreeResource {
   }
 
   bool ConnectSockets (
-      const AnimNodeResource& source_node,
+      const AnimNodeResource* source_node,
       const std::string& source_socket_name,
-      const AnimNodeResource& target_node,
+      const AnimNodeResource* target_node,
-      const std::string& target_socket_name) {
+      const std::string& target_socket_name);
-    size_t source_node_index = GetNodeIndex(source_node);
-    size_t target_node_index = GetNodeIndex(target_node);
-
-    if (source_node_index >= m_nodes.size()
-        || target_node_index >= m_nodes.size()) {
-      std::cerr << "Cannot connect nodes: could not find nodes." << std::endl;
-      return false;
-    }
-
-    Socket* source_socket =
-        source_node.m_socket_accessor->GetOutputSocket(source_socket_name.c_str());
-    Socket* target_socket =
-        target_node.m_socket_accessor->GetInputSocket(target_socket_name.c_str());
-
-    if (source_socket == nullptr || target_socket == nullptr) {
-      std::cerr << "Cannot connect nodes: could not find sockets." << std::endl;
-      return false;
-    }
-
-    BlendTreeConnectionResource connection;
-    connection.source_node_index = source_node_index;
-    connection.source_socket_name = source_socket_name;
-    connection.target_node_index = target_node_index;
-    connection.target_socket_name = target_socket_name;
-    m_connections.push_back(connection);
-
-    return true;
-  }
 
   std::vector<Socket*> GetConstantNodeInputs(
       std::vector<NodeDescriptorBase*>& instance_node_descriptors) const {
@@ -125,7 +92,7 @@ struct BlendTreeResource {
         Socket& input = instance_node_descriptors[i]->m_inputs[j];
 
         if (*input.m_reference.ptr_ptr == nullptr) {
-          memcpy(&input.m_value, &m_nodes[i].m_socket_accessor->m_inputs[j].m_value, sizeof(Socket::SocketValue));
+          memcpy(&input.m_value, &m_nodes[i]->m_socket_accessor->m_inputs[j].m_value, sizeof(Socket::SocketValue));
           result.push_back(&input);
         }
       }
@@ -147,8 +114,8 @@ struct StateMachineResource {
   std::vector<StateMachineTransitionResources> m_transitions;
 };
 
-struct AnimGraphResource {
+struct AnimGraphResource: AnimNodeResource {
-  std::string m_type;
+  std::string m_graph_type_name;
   std::string m_name;
 
   BlendTreeResource m_blend_tree_resource;
@@ -163,7 +130,6 @@ struct AnimGraphResource {
  private:
   // BlendTree
   bool SaveBlendTreeResourceToFile(const char* filename) const;
-  bool LoadBlendTreeResourceFromJson(nlohmann::json const& json_data);
   void CreateBlendTreeRuntimeNodeInstances(AnimGraphBlendTree& result) const;
   void PrepareBlendTreeIOData(AnimGraphBlendTree& instance) const;
   void SetRuntimeNodeProperties(AnimGraphBlendTree& result) const;
@@ -172,4 +138,30 @@ struct AnimGraphResource {
   bool LoadStateMachineResourceFromJson(nlohmann::json const& json_data);
 };
 
+static inline AnimNodeResource* AnimNodeResourceFactory(
+    const std::string& node_type_name) {
+  AnimNodeResource* result;
+
+  if (node_type_name == "BlendTree") {
+    AnimGraphResource* blend_tree_resource = new AnimGraphResource();
+    blend_tree_resource->m_blend_tree_resource.InitGraphConnectors();
+    result = blend_tree_resource;
+  } else {
+    result = new AnimNodeResource();
+  }
+
+  result->m_node_type_name = node_type_name;
+
+  if (node_type_name == "BlendTreeSockets") {
+    result->m_anim_node = AnimNodeFactory("BlendTree");
+    result->m_socket_accessor = new NodeDescriptorBase();
+  } else {
+    result->m_anim_node = AnimNodeFactory(node_type_name);
+    result->m_socket_accessor =
+        AnimNodeDescriptorFactory(node_type_name, result->m_anim_node);
+  }
+
+  return result;
+}
+
 #endif  //ANIMTESTBED_ANIMGRAPHRESOURCE_H

tests/AnimGraphResourceTests.cc

@@ -55,24 +55,23 @@ TEST_CASE("InputAttributeConversion", "[AnimGraphResource]") {
 TEST_CASE("AnimSamplerGraph", "[AnimGraphResource]") {
   AnimGraphResource graph_resource;
   graph_resource.m_name = "AnimSamplerBlendTree";
-  graph_resource.m_type = "BlendTree";
+  graph_resource.m_graph_type_name = "BlendTree";
 
   BlendTreeResource& blend_tree_resource = graph_resource.m_blend_tree_resource;
-  blend_tree_resource.Reset();
   blend_tree_resource.InitGraphConnectors();
 
   // Prepare graph inputs and outputs
   blend_tree_resource.m_nodes.push_back(AnimNodeResourceFactory("AnimSampler"));
   size_t walk_node_index = blend_tree_resource.m_nodes.size() - 1;
 
-  AnimNodeResource& walk_node = blend_tree_resource.m_nodes[walk_node_index];
+  AnimNodeResource* walk_node = blend_tree_resource.m_nodes[walk_node_index];
-  walk_node.m_name = "WalkAnim";
+  walk_node->m_name = "WalkAnim";
-  walk_node.m_socket_accessor->SetPropertyValue(
+  walk_node->m_socket_accessor->SetPropertyValue(
       "Filename",
       std::string("media/Walking-loop.ozz"));
 
-  AnimNodeResource& graph_node = blend_tree_resource.m_nodes[0];
+  AnimNodeResource* graph_node = blend_tree_resource.m_nodes[0];
-  graph_node.m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
+  graph_node->m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
 
   blend_tree_resource.ConnectSockets(
       walk_node,
@@ -80,10 +79,10 @@ TEST_CASE("AnimSamplerGraph", "[AnimGraphResource]") {
       blend_tree_resource.GetGraphOutputNode(),
       "GraphOutput");
 
-  graph_resource.SaveToFile("AnimSamplerBlendTree.json");
+  graph_resource.SaveToFile("TestGraphAnimSamplerBlendTree.json");
 
   AnimGraphResource graph_resource_loaded;
-  graph_resource_loaded.LoadFromFile("AnimSamplerBlendTree.json");
+  graph_resource_loaded.LoadFromFile("TestGraphAnimSamplerBlendTree.json");
 
   AnimGraphBlendTree anim_graph_blend_tree;
   graph_resource_loaded.CreateBlendTreeInstance(anim_graph_blend_tree);
@@ -96,8 +95,8 @@ TEST_CASE("AnimSamplerGraph", "[AnimGraphResource]") {
   REQUIRE(anim_graph_blend_tree.Init(graph_context));
 
   REQUIRE(anim_graph_blend_tree.m_nodes.size() == 3);
-  REQUIRE(anim_graph_blend_tree.m_nodes[0]->m_node_type_name == "BlendTree");
+  REQUIRE(anim_graph_blend_tree.m_nodes[0]->m_node_type_name == "BlendTreeSockets");
-  REQUIRE(anim_graph_blend_tree.m_nodes[1]->m_node_type_name == "BlendTree");
+  REQUIRE(anim_graph_blend_tree.m_nodes[1]->m_node_type_name == "BlendTreeSockets");
   REQUIRE(anim_graph_blend_tree.m_nodes[2]->m_node_type_name == "AnimSampler");
 
   // connections within the graph
@@ -139,7 +138,7 @@ TEST_CASE("AnimSamplerGraph", "[AnimGraphResource]") {
 TEST_CASE("AnimSamplerSpeedScaleGraph", "[AnimGraphResource]") {
   AnimGraphResource graph_resource;
   graph_resource.m_name = "AnimSamplerSpeedScaleGraph";
-  graph_resource.m_type = "BlendTree";
+  graph_resource.m_graph_type_name = "BlendTree";
 
   BlendTreeResource& blend_tree_resource = graph_resource.m_blend_tree_resource;
   blend_tree_resource.Reset();
@@ -152,22 +151,22 @@ TEST_CASE("AnimSamplerSpeedScaleGraph", "[AnimGraphResource]") {
   blend_tree_resource.m_nodes.push_back(AnimNodeResourceFactory("SpeedScale"));
   size_t speed_scale_node_index = blend_tree_resource.m_nodes.size() - 1;
 
-  AnimNodeResource& walk_node = blend_tree_resource.m_nodes[walk_node_index];
+  AnimNodeResource* walk_node = blend_tree_resource.m_nodes[walk_node_index];
-  walk_node.m_name = "WalkAnim";
+  walk_node->m_name = "WalkAnim";
-  walk_node.m_socket_accessor->SetPropertyValue(
+  walk_node->m_socket_accessor->SetPropertyValue(
       "Filename",
       std::string("media/Walking-loop.ozz"));
 
-  AnimNodeResource& speed_scale_node =
+  AnimNodeResource* speed_scale_node =
       blend_tree_resource.m_nodes[speed_scale_node_index];
-  speed_scale_node.m_name = "SpeedScale";
+  speed_scale_node->m_name = "SpeedScale";
   float speed_scale_value = 1.35f;
-  speed_scale_node.m_socket_accessor->SetInputValue(
+  speed_scale_node->m_socket_accessor->SetInputValue(
       "SpeedScale",
       speed_scale_value);
 
-  AnimNodeResource& graph_node = blend_tree_resource.m_nodes[0];
+  AnimNodeResource* graph_node = blend_tree_resource.GetGraphOutputNode();
-  graph_node.m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
+  graph_node->m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
 
   blend_tree_resource.ConnectSockets(walk_node, "Output", speed_scale_node, "Input");
 
@@ -177,16 +176,15 @@ TEST_CASE("AnimSamplerSpeedScaleGraph", "[AnimGraphResource]") {
       blend_tree_resource.GetGraphOutputNode(),
       "GraphOutput");
 
-  graph_resource.SaveToFile("AnimSamplerSpeedScaleGraph.animgraph.json");
+  graph_resource.SaveToFile("TestGraphAnimSamplerSpeedScaleGraph.animgraph.json");
   AnimGraphResource graph_resource_loaded;
   graph_resource_loaded.LoadFromFile(
-      "AnimSamplerSpeedScaleGraph.animgraph.json");
+      "TestGraphAnimSamplerSpeedScaleGraph.animgraph.json");
 
   BlendTreeResource& blend_tree_resource_loaded = graph_resource_loaded.m_blend_tree_resource;
 
   Socket* speed_scale_resource_loaded_input =
-      blend_tree_resource_loaded.m_nodes[speed_scale_node_index]
+      blend_tree_resource_loaded.m_nodes[speed_scale_node_index]->m_socket_accessor->GetInputSocket("SpeedScale");
-          .m_socket_accessor->GetInputSocket("SpeedScale");
   REQUIRE(speed_scale_resource_loaded_input != nullptr);
 
   REQUIRE_THAT(
@@ -203,7 +201,7 @@ TEST_CASE("AnimSamplerSpeedScaleGraph", "[AnimGraphResource]") {
 TEST_CASE("Blend2Graph", "[AnimGraphResource]") {
   AnimGraphResource graph_resource;
   graph_resource.m_name = "WalkRunBlendGraph";
-  graph_resource.m_type = "BlendTree";
+  graph_resource.m_graph_type_name = "BlendTree";
 
   BlendTreeResource& blend_tree_resource = graph_resource.m_blend_tree_resource;
   blend_tree_resource.Reset();
@@ -219,25 +217,25 @@ TEST_CASE("Blend2Graph", "[AnimGraphResource]") {
   blend_tree_resource.m_nodes.push_back(AnimNodeResourceFactory("Blend2"));
   size_t blend_node_index = blend_tree_resource.m_nodes.size() - 1;
 
-  AnimNodeResource& walk_node = blend_tree_resource.m_nodes[walk_node_index];
+  AnimNodeResource* walk_node = blend_tree_resource.m_nodes[walk_node_index];
-  walk_node.m_name = "WalkAnim";
+  walk_node->m_name = "WalkAnim";
-  walk_node.m_socket_accessor->SetPropertyValue(
+  walk_node->m_socket_accessor->SetPropertyValue(
       "Filename",
       std::string("media/Walking-loop.ozz"));
-  AnimNodeResource& run_node = blend_tree_resource.m_nodes[run_node_index];
+  AnimNodeResource* run_node = blend_tree_resource.m_nodes[run_node_index];
-  run_node.m_socket_accessor->SetPropertyValue(
+  run_node->m_socket_accessor->SetPropertyValue(
       "Filename",
       std::string("media/Running0-loop.ozz"));
-  run_node.m_name = "RunAnim";
+  run_node->m_name = "RunAnim";
-  AnimNodeResource& blend_node = blend_tree_resource.m_nodes[blend_node_index];
+  AnimNodeResource* blend_node = blend_tree_resource.m_nodes[blend_node_index];
-  blend_node.m_name = "BlendWalkRun";
+  blend_node->m_name = "BlendWalkRun";
 
-  AnimNodeResource& graph_node = blend_tree_resource.m_nodes[0];
+  AnimNodeResource* graph_node = blend_tree_resource.GetGraphOutputNode();
-  graph_node.m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
+  graph_node->m_socket_accessor->RegisterInput<AnimData>("GraphOutput", nullptr);
 
-  REQUIRE(graph_node.m_socket_accessor->m_inputs.size() == 1);
+  REQUIRE(graph_node->m_socket_accessor->m_inputs.size() == 1);
-  REQUIRE(blend_node.m_socket_accessor->GetInputIndex("Input0") == 0);
+  REQUIRE(blend_node->m_socket_accessor->GetInputIndex("Input0") == 0);
-  REQUIRE(blend_node.m_socket_accessor->GetInputIndex("Input1") == 1);
+  REQUIRE(blend_node->m_socket_accessor->GetInputIndex("Input1") == 1);
 
   blend_tree_resource.ConnectSockets(walk_node, "Output", blend_node, "Input0");
   blend_tree_resource.ConnectSockets(run_node, "Output", blend_node, "Input1");
@@ -247,10 +245,10 @@ TEST_CASE("Blend2Graph", "[AnimGraphResource]") {
       blend_tree_resource.GetGraphOutputNode(),
       "GraphOutput");
 
-  graph_resource.SaveToFile("Blend2Graph.animgraph.json");
+  graph_resource.SaveToFile("TestGraphBlend2Graph.animgraph.json");
 
   AnimGraphResource graph_resource_loaded;
-  graph_resource_loaded.LoadFromFile("Blend2Graph.animgraph.json");
+  graph_resource_loaded.LoadFromFile("TestGraphBlend2Graph.animgraph.json");
 
   AnimGraphBlendTree blend_tree_graph;
   graph_resource_loaded.CreateBlendTreeInstance(blend_tree_graph);
@@ -263,8 +261,8 @@ TEST_CASE("Blend2Graph", "[AnimGraphResource]") {
   REQUIRE(blend_tree_graph.Init(graph_context));
 
   REQUIRE(blend_tree_graph.m_nodes.size() == 5);
-  REQUIRE(blend_tree_graph.m_nodes[0]->m_node_type_name == "BlendTree");
+  REQUIRE(blend_tree_graph.m_nodes[0]->m_node_type_name == "BlendTreeSockets");
-  REQUIRE(blend_tree_graph.m_nodes[1]->m_node_type_name == "BlendTree");
+  REQUIRE(blend_tree_graph.m_nodes[1]->m_node_type_name == "BlendTreeSockets");
   REQUIRE(blend_tree_graph.m_nodes[2]->m_node_type_name == "AnimSampler");
   REQUIRE(blend_tree_graph.m_nodes[3]->m_node_type_name == "AnimSampler");
   REQUIRE(blend_tree_graph.m_nodes[4]->m_node_type_name == "Blend2");
@@ -349,7 +347,7 @@ TEST_CASE("Blend2Graph", "[AnimGraphResource]") {
 TEST_CASE("ResourceSaveLoadMathGraphInputs", "[AnimGraphResource]") {
   AnimGraphResource graph_resource_origin;
   graph_resource_origin.m_name = "TestInputOutputGraph";
-  graph_resource_origin.m_type = "BlendTree";
+  graph_resource_origin.m_graph_type_name = "BlendTree";
 
   BlendTreeResource& blend_tree_resource = graph_resource_origin.m_blend_tree_resource;
   blend_tree_resource.Reset();
@@ -359,23 +357,23 @@ TEST_CASE("ResourceSaveLoadMathGraphInputs", "[AnimGraphResource]") {
   blend_tree_resource.m_nodes.push_back(AnimNodeResourceFactory("MathFloatToVec3Node"));
   size_t float_to_vec3_node_index = blend_tree_resource.m_nodes.size() - 1;
 
-  AnimNodeResource& graph_output_node =
+  AnimNodeResource* graph_output_node =
       blend_tree_resource.GetGraphOutputNode();
-  graph_output_node.m_socket_accessor->RegisterInput<float>(
+  graph_output_node->m_socket_accessor->RegisterInput<float>(
       "GraphFloatOutput",
       nullptr);
-  graph_output_node.m_socket_accessor->RegisterInput<Vec3>(
+  graph_output_node->m_socket_accessor->RegisterInput<Vec3>(
       "GraphVec3Output",
       nullptr);
 
-  AnimNodeResource& graph_input_node =
+  AnimNodeResource* graph_input_node =
       blend_tree_resource.GetGraphInputNode();
-  graph_input_node.m_socket_accessor->RegisterOutput<float>(
+  graph_input_node->m_socket_accessor->RegisterOutput<float>(
       "GraphFloatInput",
       nullptr);
 
   // Prepare graph inputs and outputs
-  AnimNodeResource& float_to_vec3_node =
+  AnimNodeResource* float_to_vec3_node =
       blend_tree_resource.m_nodes[float_to_vec3_node_index];
 
   REQUIRE(blend_tree_resource.ConnectSockets(
@@ -407,7 +405,7 @@ TEST_CASE("ResourceSaveLoadMathGraphInputs", "[AnimGraphResource]") {
       "GraphVec3Output"));
 
   WHEN("Saving and loading graph resource") {
-    const char* filename = "ResourceSaveLoadGraphInputs.json";
+    const char* filename = "TestGraphResourceSaveLoadGraphInputs.json";
     graph_resource_origin.SaveToFile(filename);
 
     AnimGraphResource graph_resource_loaded;
@@ -415,31 +413,31 @@ TEST_CASE("ResourceSaveLoadMathGraphInputs", "[AnimGraphResource]") {
 
     BlendTreeResource& graph_blend_tree_loaded = graph_resource_loaded.m_blend_tree_resource;
 
-    const AnimNodeResource& graph_loaded_output_node =
+    const AnimNodeResource* graph_loaded_output_node =
         graph_blend_tree_loaded.m_nodes[0];
-    const AnimNodeResource& graph_loaded_input_node =
+    const AnimNodeResource* graph_loaded_input_node =
         graph_blend_tree_loaded.m_nodes[1];
 
     THEN("Graph inputs and outputs must be in loaded resource as well.") {
       REQUIRE(
-          graph_output_node.m_socket_accessor->m_inputs.size()
+          graph_output_node->m_socket_accessor->m_inputs.size()
-          == graph_loaded_output_node.m_socket_accessor->m_inputs.size());
+          == graph_loaded_output_node->m_socket_accessor->m_inputs.size());
 
       REQUIRE(
-          graph_input_node.m_socket_accessor->m_outputs.size()
+          graph_input_node->m_socket_accessor->m_outputs.size()
-          == graph_loaded_input_node.m_socket_accessor->m_outputs.size());
+          == graph_loaded_input_node->m_socket_accessor->m_outputs.size());
 
       REQUIRE(
-          graph_loaded_input_node.m_socket_accessor->GetOutputSocket(
+          graph_loaded_input_node->m_socket_accessor->GetOutputSocket(
               "GraphFloatInput")
           != nullptr);
 
       REQUIRE(
-          graph_loaded_output_node.m_socket_accessor->GetInputSocket(
+          graph_loaded_output_node->m_socket_accessor->GetInputSocket(
               "GraphFloatOutput")
           != nullptr);
       REQUIRE(
-          graph_loaded_output_node.m_socket_accessor->GetInputSocket(
+          graph_loaded_output_node->m_socket_accessor->GetInputSocket(
               "GraphVec3Output")
           != nullptr);
 
@@ -488,7 +486,7 @@ TEST_CASE("ResourceSaveLoadMathGraphInputs", "[AnimGraphResource]") {
 TEST_CASE("SimpleMathEvaluations", "[AnimGraphResource]") {
   AnimGraphResource graph_resource_origin;
   graph_resource_origin.m_name = "TestSimpleMathGraph";
-  graph_resource_origin.m_type = "BlendTree";
+  graph_resource_origin.m_graph_type_name = "BlendTree";
 
   BlendTreeResource& blend_tree_resource = graph_resource_origin.m_blend_tree_resource;
   blend_tree_resource.Reset();
@@ -501,29 +499,29 @@ TEST_CASE("SimpleMathEvaluations", "[AnimGraphResource]") {
   blend_tree_resource.m_nodes.push_back(AnimNodeResourceFactory("MathAddNode"));
   size_t math_add1_node_index = blend_tree_resource.m_nodes.size() - 1;
 
-  AnimNodeResource& graph_output_node =
+  AnimNodeResource* graph_output_node =
       blend_tree_resource.GetGraphOutputNode();
 
-  graph_output_node.m_socket_accessor->RegisterInput<float>(
+  graph_output_node->m_socket_accessor->RegisterInput<float>(
       "GraphFloat0Output",
       nullptr);
-  graph_output_node.m_socket_accessor->RegisterInput<float>(
+  graph_output_node->m_socket_accessor->RegisterInput<float>(
       "GraphFloat1Output",
       nullptr);
-  graph_output_node.m_socket_accessor->RegisterInput<float>(
+  graph_output_node->m_socket_accessor->RegisterInput<float>(
       "GraphFloat2Output",
       nullptr);
 
-  AnimNodeResource& graph_input_node =
+  AnimNodeResource* graph_input_node =
       blend_tree_resource.GetGraphInputNode();
-  graph_input_node.m_socket_accessor->RegisterOutput<float>(
+  graph_input_node->m_socket_accessor->RegisterOutput<float>(
       "GraphFloatInput",
       nullptr);
 
   // Prepare graph inputs and outputs
-  AnimNodeResource& math_add0_node =
+  AnimNodeResource* math_add0_node =
       blend_tree_resource.m_nodes[math_add0_node_index];
-  AnimNodeResource& math_add1_node =
+  AnimNodeResource* math_add1_node =
       blend_tree_resource.m_nodes[math_add1_node_index];
 
   // direct output
@@ -572,7 +570,7 @@ TEST_CASE("SimpleMathEvaluations", "[AnimGraphResource]") {
       "GraphFloat2Output"));
 
   WHEN("Saving and loading graph resource") {
-    const char* filename = "ResourceSaveLoadGraphInputs.json";
+    const char* filename = "TestGraphResourceSaveLoadGraphInputs.json";
     graph_resource_origin.SaveToFile(filename);
 
     AnimGraphResource graph_resource_loaded;
@@ -618,4 +616,154 @@ TEST_CASE("SimpleMathEvaluations", "[AnimGraphResource]") {
       }
     }
   }
+}
+
+
+//
+// Tests whether BlendTree within a BlendTree can be saved and loaded
+//
+//   +-----------Parent BlendTree-------------+
+//   |                                        |
+//   |           +-----Embd Btree---+         |
+//   |  AnmSmpl--+-\                |         |
+//   |           |  \-SpdScale------+--Out    |
+//   |           |------------------+         |
+//   |                                        |
+//   +----------------------------------------+
+//
+TEST_CASE("EmbeddedBlendTreeSaveLoad", "[AnimGraphResource]") {
+  const char* parent_graph_filename = "TestGraphEmbeddedBlendTree.json";
+  AnimGraphResource parent_graph_resource;
+  parent_graph_resource.m_name = "ParentBlendTree";
+  parent_graph_resource.m_graph_type_name = "BlendTree";
+  parent_graph_resource.m_node_type_name = "BlendTree";
+
+  BlendTreeResource& parent_blend_tree_resource =
+      parent_graph_resource.m_blend_tree_resource;
+  parent_blend_tree_resource.Reset();
+  parent_blend_tree_resource.InitGraphConnectors();
+
+  // Setup parent outputs
+  AnimNodeResource* parent_blend_tree_outputs = parent_blend_tree_resource.GetGraphOutputNode();
+  parent_blend_tree_outputs->m_socket_accessor->RegisterInput<AnimData>("Output", nullptr);
+
+  // Parent AnimSampler
+  parent_blend_tree_resource.m_nodes.push_back(
+      AnimNodeResourceFactory("AnimSampler"));
+
+  AnimNodeResource* walk_node =
+      parent_blend_tree_resource.m_nodes.back();
+  walk_node->m_name = "WalkAnim";
+  walk_node->m_socket_accessor->SetPropertyValue(
+      "Filename",
+      std::string("media/Walking-loop.ozz"));
+
+  //
+  // Embedded Tree
+  //
+  parent_blend_tree_resource.m_nodes.push_back(
+      AnimNodeResourceFactory("BlendTree"));
+  size_t embedded_blend_tree_node_index =
+      parent_blend_tree_resource.m_nodes.size() - 1;
+  AnimGraphResource* embedded_graph =
+      dynamic_cast<AnimGraphResource*>(parent_blend_tree_resource.m_nodes.back());
+  embedded_graph->m_name = "EmbeddedBlendTree";
+  embedded_graph->m_node_type_name = "BlendTree";
+  BlendTreeResource* embedded_blend_tree_resource = &embedded_graph->m_blend_tree_resource;
+
+  // Embedded: outputs
+  AnimNodeResource* embedded_outputs =
+      embedded_blend_tree_resource->GetGraphOutputNode();
+  embedded_outputs->m_socket_accessor->RegisterInput<AnimData>(
+      "AnimOutput",
+      nullptr);
+
+  // Embedded: inputs
+  AnimNodeResource* embedded_inputs =
+      embedded_blend_tree_resource->GetGraphInputNode();
+  embedded_inputs->m_socket_accessor->RegisterOutput<AnimData>(
+      "AnimInput",
+      nullptr);
+
+  // Embedded: SpeedScale node
+  embedded_blend_tree_resource->m_nodes.push_back(
+      AnimNodeResourceFactory("SpeedScale"));
+  AnimNodeResource* embedded_speed_scale_resource = embedded_blend_tree_resource->m_nodes.back();
+
+  embedded_blend_tree_resource->ConnectSockets(embedded_inputs, "AnimInput", embedded_speed_scale_resource, "Input");
+  embedded_blend_tree_resource->ConnectSockets(embedded_speed_scale_resource, "Output", embedded_outputs, "AnimOutput");
+
+  //
+  // Parent: setup connections
+  //
+  REQUIRE(parent_blend_tree_resource.ConnectSockets(walk_node, "Output", embedded_graph, "AnimInput"));
+  REQUIRE(parent_blend_tree_resource.ConnectSockets(embedded_graph, "AnimOutput", parent_blend_tree_outputs, "Output"));
+
+  parent_graph_resource.SaveToFile(parent_graph_filename);
+
+  //
+  // Load the graph
+  //
+  AnimGraphResource parent_graph_resource_loaded;
+  parent_graph_resource_loaded.LoadFromFile(parent_graph_filename);
+
+  //
+  // Check the loaded parent graph
+  //
+  CHECK(parent_graph_resource.m_name == parent_graph_resource_loaded.m_name);
+  CHECK(parent_graph_resource.m_graph_type_name == parent_graph_resource_loaded.m_graph_type_name);
+  CHECK(parent_graph_resource.m_node_type_name
+      == parent_graph_resource_loaded.m_node_type_name);
+  
+  const BlendTreeResource& parent_blend_tree_resource_loaded = parent_graph_resource_loaded.m_blend_tree_resource; 
+  
+  CHECK(parent_blend_tree_resource.m_nodes.size() == parent_blend_tree_resource_loaded.m_nodes.size());
+  for (size_t i = 0; i < parent_blend_tree_resource.m_nodes.size(); i++) {
+    const AnimNodeResource* parent_node = parent_blend_tree_resource.m_nodes[i];
+    const AnimNodeResource* parent_node_loaded = parent_blend_tree_resource_loaded.m_nodes[i];
+    
+    CHECK(parent_node->m_name == parent_node_loaded->m_name);
+    CHECK(parent_node->m_node_type_name == parent_node_loaded->m_node_type_name);
+  }
+  
+  CHECK(parent_blend_tree_resource.m_connections.size() == parent_blend_tree_resource_loaded.m_connections.size());
+  for (size_t i = 0; i < parent_blend_tree_resource.m_connections.size(); i++) {
+    const BlendTreeConnectionResource& parent_connection = parent_blend_tree_resource.m_connections[i];
+    const BlendTreeConnectionResource& parent_connection_loaded = parent_blend_tree_resource_loaded.m_connections[i];
+    
+    CHECK(parent_connection.source_node_index == parent_connection_loaded.source_node_index);
+    CHECK(parent_connection.source_socket_name == parent_connection_loaded.source_socket_name);
+    CHECK(parent_connection.target_node_index == parent_connection_loaded.target_node_index);
+    CHECK(parent_connection.target_socket_name == parent_connection_loaded.target_socket_name);
+  }
+
+  //
+  // Check the loaded embedded graph
+  //
+  REQUIRE(parent_blend_tree_resource_loaded.m_nodes[3]->m_node_type_name == "BlendTree");
+  
+  const AnimGraphResource* embedded_graph_loaded = dynamic_cast<AnimGraphResource*>(parent_blend_tree_resource_loaded.m_nodes[3]);
+  const BlendTreeResource& embedded_blend_tree_resource_loaded = embedded_graph_loaded->m_blend_tree_resource;
+  
+  CHECK(embedded_blend_tree_resource->m_nodes.size() == embedded_blend_tree_resource_loaded.m_nodes.size());
+  CHECK(embedded_blend_tree_resource->m_connections.size() == embedded_blend_tree_resource_loaded.m_connections.size());
+  
+  for (size_t i = 0; i < embedded_blend_tree_resource->m_nodes.size(); i++) {
+    const AnimNodeResource* parent_node = embedded_blend_tree_resource->m_nodes[i];
+    const AnimNodeResource* parent_node_loaded = embedded_blend_tree_resource_loaded.m_nodes[i];
+    
+    CHECK(parent_node->m_name == parent_node_loaded->m_name);
+    CHECK(parent_node->m_node_type_name == parent_node_loaded->m_node_type_name);
+  }
+  
+  CHECK(embedded_blend_tree_resource->m_connections.size() == embedded_blend_tree_resource_loaded.m_connections.size());
+  for (size_t i = 0; i < embedded_blend_tree_resource->m_connections.size(); i++) {
+    const BlendTreeConnectionResource& embedded_connection = embedded_blend_tree_resource->m_connections[i];
+    const BlendTreeConnectionResource& embedded_connection_loaded = embedded_blend_tree_resource_loaded.m_connections[i];
+    
+    CHECK(embedded_connection.source_node_index == embedded_connection_loaded.source_node_index);
+    CHECK(embedded_connection.source_socket_name == embedded_connection_loaded.source_socket_name);
+    CHECK(embedded_connection.target_node_index == embedded_connection_loaded.target_node_index);
+    CHECK(embedded_connection.target_socket_name == embedded_connection_loaded.target_socket_name);
+  }
 }