diff --git a/libraries/workload/src/workload/ClassificationTracker.cpp b/libraries/workload/src/workload/ClassificationTracker.cpp
index 009549737f..15066b1050 100644
--- a/libraries/workload/src/workload/ClassificationTracker.cpp
+++ b/libraries/workload/src/workload/ClassificationTracker.cpp
@@ -18,7 +18,17 @@ using namespace workload;
 void ClassificationTracker::configure(const Config& config) {
 }
 
-void ClassificationTracker::run(const workload::WorkloadContextPointer& renderContext, Outputs& outputs) {
-
+void ClassificationTracker::run(const WorkloadContextPointer& context, Outputs& outputs) {
+    auto space = context->_space;
+    if (space) {
+        Changes changes;
+        space->categorizeAndGetChanges(changes);
+        outputs.resize(workload::Space::NUM_TRANSITIONS);
+        for (uint32_t i = 0; i < changes.size(); ++i) {
+            int32_t j = Space::computeTransitionIndex(changes[i].prevRegion, changes[i].region);
+            assert(j >= 0 && j < workload::Space::NUM_TRANSITIONS);
+            outputs[j].push_back(changes[i].proxyId);
+        }
+    }
 }
 
diff --git a/libraries/workload/src/workload/ClassificationTracker.h b/libraries/workload/src/workload/ClassificationTracker.h
index ca7a919769..e3364950da 100644
--- a/libraries/workload/src/workload/ClassificationTracker.h
+++ b/libraries/workload/src/workload/ClassificationTracker.h
@@ -29,7 +29,7 @@ namespace workload {
     class ClassificationTracker {
     public:
         using Config = ClassificationTrackerConfig;
-        using Outputs = Classifications;
+        using Outputs = SortedChanges;
         using JobModel = workload::Job::ModelO<ClassificationTracker, Outputs, Config>;
 
         ClassificationTracker() {}
diff --git a/libraries/workload/src/workload/Space.h b/libraries/workload/src/workload/Space.h
index ee06383288..eef1fc17cd 100644
--- a/libraries/workload/src/workload/Space.h
+++ b/libraries/workload/src/workload/Space.h
@@ -24,6 +24,11 @@ namespace workload {
 
 class Space {
 public:
+    static const int32_t NUM_CLASSIFICATIONS = 4;
+    static const int32_t NUM_TRANSITIONS = NUM_CLASSIFICATIONS * (NUM_CLASSIFICATIONS - 1);
+
+    static int32_t computeTransitionIndex(int32_t prevIndex, int32_t newIndex);
+
     static const uint8_t REGION_NEAR = 0;
     static const uint8_t REGION_MIDDLE = 1;
     static const uint8_t REGION_FAR = 2;
@@ -45,12 +50,12 @@ public:
     class View {
     public:
         View(const glm::vec3& pos, float nearRadius, float midRadius, float farRadius) : center(pos) {
-            radiuses[0] = nearRadius;
-            radiuses[1] = midRadius;
-            radiuses[2] = farRadius;
+            radiuses[REGION_NEAR] = nearRadius;
+            radiuses[REGION_MIDDLE] = midRadius;
+            radiuses[REGION_FAR] = farRadius;
         }
-        glm::vec3 center { 0.0f, 0.0f, 0.0f };
-        float radiuses[3] { 0.0f, 0.0f, 0.0f };
+        glm::vec3 center;
+        float radiuses[NUM_CLASSIFICATIONS - 1];
     };
 
     class Change {
@@ -84,8 +89,44 @@ private:
     std::vector<int32_t> _freeIndices;
 };
 
+inline int32_t Space::computeTransitionIndex(int32_t prevIndex, int32_t newIndex) {
+    // given prevIndex and newIndex compute an index into the transition list,
+    // where the lists between unchanged indices don't exist (signaled by index = -1).
+    //
+    // Given an NxN array
+    // let p = i + N * j
+    //
+    // then k = -1                   when i == j
+    //        = p - (1 + p/(N+1))    when i != j
+    //
+    //    i   0       1       2       3
+    // j  +-------+-------+-------+-------+
+    //    |p = 0  |    1  |    2  |    3  |
+    // 0  |       |       |       |       |
+    //    |k = -1 |    0  |    1  |    2  |
+    //    +-------+-------+-------+-------+
+    //    |     4 |    5  |    6  |    7  |
+    // 1  |       |       |       |       |
+    //    |     3 |    -1 |    4  |    5  |
+    //    +-------+-------+-------+-------+
+    //    |     8 |     9 |   10  |   11  |
+    // 2  |       |       |       |       |
+    //    |     6 |     7 |    -1 |    8  |
+    //    +-------+-------+-------+-------+
+    //    |    12 |    13 |    14 |    15 |
+    // 3  |       |       |       |       |
+    //    |     9 |    10 |    11 |    -1 |
+    //    +-------+-------+-------+-------+
+    int32_t p = prevIndex + Space::NUM_CLASSIFICATIONS * newIndex;
+    if (0 == (p % (Space::NUM_CLASSIFICATIONS + 1))) {
+        return -1;
+    }
+    return p - (1 + p / (Space::NUM_CLASSIFICATIONS + 1));
+}
+
 using SpacePointer = std::shared_ptr<Space>;
-using Classifications = std::vector<Space::Change>;
+using Changes = std::vector<Space::Change>;
+using SortedChanges = std::vector<std::vector<int32_t>>;
 
 } // namespace workload