diff --git a/src/AnimGraphResource.cc b/src/AnimGraphResource.cc
index 177a957..7864282 100644
--- a/src/AnimGraphResource.cc
+++ b/src/AnimGraphResource.cc
@@ -351,6 +351,12 @@ bool AnimGraphResource::loadFromFile(const char* filename) {
   return true;
 }
 
+void AnimGraph::MarkActiveNodes() {
+  m_frame_counter++;
+
+  // TODO: start from output and trigger updating of the frame counter.
+}
+
 void* AnimGraph::GetOutput(const std::string& name) const {
   Socket* socket = m_socket_accessor->FindInputSocket(name);
   if (socket == nullptr) {
diff --git a/src/AnimGraphResource.h b/src/AnimGraphResource.h
index 469f20d..4a40399 100644
--- a/src/AnimGraphResource.h
+++ b/src/AnimGraphResource.h
@@ -89,9 +89,15 @@ struct AnimNode {
   bool m_is_time_synced;
   float m_time_now;
   float m_time_last;
+  int m_frame_counter = 0;
   SyncTrack m_sync_track;
 };
 
+struct AnimNodeInput {
+  AnimNode* m_node;
+  std::string m_input_name;
+};
+
 struct NodeSocketAccessorBase {
   NodeSocketAccessorBase() {}
   virtual ~NodeSocketAccessorBase() {}
@@ -515,12 +521,19 @@ struct AnimGraph {
     delete m_socket_accessor;
   }
 
+  void MarkActiveNodes();
+  bool CheckNodeActive(int node_index) {
+    assert(node_index < m_nodes.size());
+    return m_nodes[node_index]->m_frame_counter == m_frame_counter;
+  }
   void UpdateTime(float dt);
   void Evaluate();
 
+  int m_frame_counter;
   AnimData m_local_transforms;
+
   std::vector<AnimNode*> m_nodes;
-  std::vector<std::vector<AnimNode*> > m_node_inputs;
+  std::vector<std::vector<AnimNodeInput> > m_node_inputs;
   NodeSocketAccessorBase* m_socket_accessor;
   char* m_input_buffer = nullptr;
   char* m_output_buffer = nullptr;
@@ -531,6 +544,22 @@ struct AnimGraph {
   void* GetOutput(const std::string& name) const;
   void* GetInput(const std::string& name) const;
 
+  AnimNode* getAnimNodeForInput(
+      size_t node_index,
+      const std::string& input_name) {
+    assert(node_index < m_nodes.size());
+    assert(node_index < m_node_inputs.size());
+
+    std::vector<AnimNodeInput>& node_inputs = m_node_inputs[node_index];
+    for (size_t i = 0, n = node_inputs.size(); i < n; i++) {
+      if (node_inputs[i].m_input_name == input_name) {
+        return node_inputs[i].m_node;
+      }
+    }
+
+    return nullptr;
+  }
+
   AnimNode* getAnimNode(const char* name) {
     for (size_t i = 0; i < m_nodes.size(); i++) {
       if (m_nodes[i]->m_name == name) {
@@ -562,7 +591,21 @@ struct AnimGraph {
       node->m_name = node_resource.m_name;
       node->m_node_type_name = node_resource.m_type_name;
       result.m_nodes.push_back(node);
-      result.m_node_inputs.push_back(std::vector<AnimNode*>());
+
+      assert(node_resource.m_socket_accessor != nullptr);
+      result.m_node_inputs.push_back(std::vector<AnimNodeInput>());
+      std::vector<AnimNodeInput>& node_inputs = result.m_node_inputs.back();
+      for (int j = 0, n = node_resource.m_socket_accessor->m_inputs.size();
+           j < n;
+           j++) {
+        const Socket& input_socket =
+            node_resource.m_socket_accessor->m_inputs[j];
+        AnimNodeInput input;
+        input.m_node = nullptr;
+        input.m_input_name = input_socket.m_name;
+
+        node_inputs.push_back(input);
+      }
     }
 
     // Prepare graph inputs
@@ -688,7 +731,14 @@ struct AnimGraph {
       (*source_socket->m_value.ptr_ptr) = target_socket->m_value.ptr;
 
       size_t target_node_index = result.getAnimNodeIndex(target_node);
-      result.m_node_inputs[target_node_index].push_back(source_node);
+
+      std::vector<AnimNodeInput>& node_inputs =
+          result.m_node_inputs[target_node_index];
+      for (int j = 0, n = node_inputs.size(); j < n; j++) {
+        if (node_inputs[j].m_input_name == target_socket->m_name) {
+          node_inputs[j].m_node = source_node;
+        }
+      }
 
       if (target_node_accessor != result.m_socket_accessor) {
         delete target_node_accessor;
@@ -703,6 +753,6 @@ struct AnimGraph {
   }
 };
 
-}
+}  // namespace AnimGraphCode
 
 #endif  //ANIMTESTBED_ANIMGRAPHRESOURCE_H
diff --git a/tests/AnimGraphResourceTests.cc b/tests/AnimGraphResourceTests.cc
index a2d5614..919667f 100644
--- a/tests/AnimGraphResourceTests.cc
+++ b/tests/AnimGraphResourceTests.cc
@@ -5,6 +5,8 @@
 #include "AnimGraphResource.h"
 #include "catch.hpp"
 
+using namespace AnimGraphCode;
+
 TEST_CASE("BasicGraph", "[AnimGraphResource]") {
   AnimGraphResource graph_resource;
 
@@ -100,9 +102,10 @@ TEST_CASE("BasicGraph", "[AnimGraphResource]") {
 
   CHECK(graph.m_node_inputs[anim_sampler_index0].size() == 0);
   CHECK(graph.m_node_inputs[anim_sampler_index1].size() == 0);
-  CHECK(graph.m_node_inputs[blend_index].size() == 2);
-  CHECK(graph.m_node_inputs[blend_index][0] == anim_sampler_instance0);
-  CHECK(graph.m_node_inputs[blend_index][1] == anim_sampler_instance1);
+  CHECK(graph.m_node_inputs[blend_index].size() == 3);
+  CHECK(graph.m_node_inputs[blend_index][0].m_node == anim_sampler_instance0);
+  CHECK(graph.m_node_inputs[blend_index][1].m_node == anim_sampler_instance1);
+  CHECK(graph.m_node_inputs[blend_index][2].m_node == nullptr);
 }
 
 TEST_CASE("InputAttributeConversion", "[AnimGraphResource]") {
@@ -324,12 +327,15 @@ TEST_CASE("GraphInputOutputConnectivity", "[AnimGraphResource]") {
 
         AnimData* graph_input0 = (AnimData*) anim_graph.GetInput("GraphAnimInput0");
         REQUIRE(graph_input0 == &blend2_node->m_input0);
+        REQUIRE(anim_graph.m_nodes[1] == anim_graph.getAnimNodeForInput(blend2_node_index, "Input0"));
 
         AnimData* graph_input1 = (AnimData*) anim_graph.GetInput("GraphAnimInput1");
         REQUIRE(graph_input1 == &blend2_node->m_input1);
+        REQUIRE(anim_graph.m_nodes[1] == anim_graph.getAnimNodeForInput(blend2_node_index, "Input1"));
 
         AnimData* graph_output = (AnimData*) anim_graph.GetOutput("GraphAnimOutput");
         REQUIRE(graph_output == blend2_node->m_output);
+        REQUIRE(anim_graph.m_nodes[blend2_node_index] == anim_graph.getAnimNodeForInput(0, "GraphAnimOutput"));
       }
     }
   }