Update Changelog and test (#6246)

* Update Changelog

* Update tests

Author: maryamziaa

com.unity.ml-agents/CHANGELOG.md

@@ -6,6 +6,14 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to
 [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Minor Changes
+#### com.unity.ml-agents (C#)
+- Fixed tensor indexing to use correct CHW layout (#6239)
+
+#### ml-agents / ml-agents-envs
+- Fixed CUDA/CPU mismatch in threaded training (#6245)
+
 ## [4.0.0] - 2025-08-15
 ### Major Changes
 #### com.unity.ml-agents (C#)

com.unity.ml-agents/Tests/Editor/Integrations/Match3/Match3SensorTests.cs

@@ -146,9 +146,8 @@ public void TestVisualObservations(bool fullBoard)
             {
                 expectedObs = new float[]
                 {
-                    1, 0, /**/ 0, 1, /**/ 1, 0,
-                    1, 0, /**/ 1, 0, /**/ 1, 0,
-                    1, 0, /**/ 1, 0, /**/ 1, 0,
+                    // NCHW layout: [channel0_all_positions, channel1_all_positions]
+                    1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0
                 };
 
                 expectedObs3D = new float[,,]
@@ -158,9 +157,8 @@ public void TestVisualObservations(bool fullBoard)
             {
                 expectedObs = new float[]
                 {
-                    1, 0, /*   0   */ 0, 1, /*   1   */ 0, 0, /* empty */
-                    1, 0, /*   0   */ 1, 0, /*   0   */ 0, 0, /* empty */
-                    0, 0, /* empty */ 0, 0, /* empty */ 0, 0, /* empty */
+                    // NCHW layout: [channel0_all_positions, channel1_all_positions] 
+                    1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0
                 };
 
                 expectedObs3D = new float[,,]
@@ -201,9 +199,8 @@ public void TestVisualObservationsSpecial()
 
                 var expectedObs = new float[]
                 {
-                    1, 0, /* (0) */ 0, 1, /* (1) */ 1, 0, /* (0) */
-                    1, 0, /* (0) */ 1, 0, /* (0) */ 1, 0, /* (0) */
-                    1, 0, /* (0) */ 1, 0, /* (0) */ 1, 0, /* (0) */
+                    // NCHW layout: [channel0_all_positions, channel1_all_positions]
+                    1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0
                 };
                 SensorTestHelper.CompareObservation(cellSensor, expectedObs);
 
@@ -238,9 +235,8 @@ public void TestVisualObservationsSpecial()
 
                 var expectedObs = new float[]
                 {
-                    1, 0, 0, /* (0) */ 1, 0, 0, /* (1) */ 1, 0, 0, /* (0) */
-                    0, 0, 1, /* (2) */ 1, 0, 0, /* (0) */ 1, 0, 0, /* (0) */
-                    1, 0, 0, /* (0) */ 0, 1, 0, /* (1) */ 1, 0, 0, /* (0) */
+                    // NCHW layout: [channel0_all_positions, channel1_all_positions, channel2_all_positions]
+                    1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0
                 };
                 SensorTestHelper.CompareObservation(specialSensor, expectedObs);