Refactor: separate buffer indexing and swizzling.

This also fixes a sensor data reading bug: previously, _sensorIndex was multiplied by 3 by MjEngineTool.

PiperOrigin-RevId: 451699887
Change-Id: I864bcbf8159857764854b25311a26ec5672125d9

unity/Editor/Components/MjMouseSpring.cs

@@ -159,7 +159,8 @@ namespace Mujoco {
               MujocoLib.mj_objectVelocity(
                   scene.Model, scene.Data, (int)MujocoLib.mjtObj.mjOBJ_BODY, body.MujocoId, res, 0);
               // linear velocity is in the last 3 entries
-              bodyVel = MjEngineTool.UnityVector3(res, 1);
+              bodyVel = MjEngineTool.UnityVector3(
+                  MjEngineTool.MjVector3AtEntry(res, 1));
             }
 
             float springStiffness = 100;

unity/Runtime/Components/Bodies/MjBody.cs

@@ -35,8 +35,10 @@ namespace Mujoco {
     }
 
     public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-      transform.position = MjEngineTool.UnityVector3(data->xpos, MujocoId);
+      transform.position = MjEngineTool.UnityVector3(
-      transform.rotation = MjEngineTool.UnityQuaternion(data->xquat, MujocoId);
+          MjEngineTool.MjVector3AtEntry(data->xpos, MujocoId));
+      transform.rotation = MjEngineTool.UnityQuaternion(
+          MjEngineTool.MjQuaternionAtEntry(data->xquat, MujocoId));
     }
   }
 }

unity/Runtime/Components/Bodies/MjMocapBody.cs

@@ -35,8 +35,10 @@ namespace Mujoco {
     }
 
     public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-      MjEngineTool.SetMjVector3(data->mocap_pos, transform.position, MujocoId);
+      MjEngineTool.SetMjVector3(
-      MjEngineTool.SetMjQuaternion(data->mocap_quat, transform.rotation, MujocoId);
+          MjEngineTool.MjVector3AtEntry(data->mocap_pos, MujocoId), transform.position);
+      MjEngineTool.SetMjQuaternion(
+          MjEngineTool.MjQuaternionAtEntry(data->mocap_quat, MujocoId), transform.rotation);
     }
   }
 }

unity/Runtime/Components/Sensors/MjBodyQuaternionSensor.cs

@@ -46,7 +46,7 @@ public class MjBodyQuaternionSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata, _sensorAddress);
+    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata + _sensorAddress);
   }
 }
 }

unity/Runtime/Components/Sensors/MjBodyVectorSensor.cs

@@ -71,7 +71,7 @@ public class MjBodyVectorSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    SensorReading = MjEngineTool.UnityVector3(data->sensordata, _sensorAddress);
+    SensorReading = MjEngineTool.UnityVector3(data->sensordata + _sensorAddress);
   }
 }
 }

unity/Runtime/Components/Sensors/MjGeomQuaternionSensor.cs

@@ -41,7 +41,7 @@ public class MjGeomQuaternionSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata, _sensorAddress);
+    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata + _sensorAddress);
   }
 }
 }

unity/Runtime/Components/Sensors/MjGeomVectorSensor.cs

@@ -57,7 +57,7 @@ public class MjGeomVectorSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    SensorReading = MjEngineTool.UnityVector3(data->sensordata, _sensorAddress);
+    SensorReading = MjEngineTool.UnityVector3(data->sensordata + _sensorAddress);
   }
 }
 }

unity/Runtime/Components/Sensors/MjSiteQuaternionSensor.cs

@@ -43,7 +43,7 @@ public class MjSiteQuaternionSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata, _sensorAddress);
+    SensorReading = MjEngineTool.UnityQuaternion(data->sensordata + _sensorAddress);
   }
 }
 }

unity/Runtime/Components/Sensors/MjSiteVectorSensor.cs

@@ -69,8 +69,7 @@ public class MjSiteVectorSensor : MjBaseSensor {
   }
 
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    Vector3 mjReading = new Vector3((float)data->sensordata[_sensorAddress], (float)data->sensordata[_sensorAddress + 1], (float)data->sensordata[_sensorAddress + 2]);
+    SensorReading = MjEngineTool.UnityVector3(data->sensordata + _sensorAddress);
-    SensorReading = MjEngineTool.UnityVector3(mjReading);
   }
 }
 }

unity/Runtime/Components/Shapes/MjGeom.cs

@@ -48,8 +48,10 @@ public class MjGeom : MjShapeComponent {
     var MjParent = MjHierarchyTool.FindParentComponent<MjBaseBody>(this);
     if (MjParent != null) {
       var comInParentFrame = new MjTransformation(
-          translation: MjEngineTool.UnityVector3(model->geom_pos, MujocoId),
+          translation: MjEngineTool.UnityVector3(
-          rotation: MjEngineTool.UnityQuaternion(model->geom_quat, MujocoId));
+              MjEngineTool.MjVector3AtEntry(model->geom_pos, MujocoId)),
+          rotation: MjEngineTool.UnityQuaternion(
+              MjEngineTool.MjQuaternionAtEntry(model->geom_quat, MujocoId)));
 
       // We don't want to bother calculating global transform in mujoco from mjModel,
       // so we'll assume it's the same as the Unity transfor (it's the beginning of simulation after
@@ -78,13 +80,17 @@ public class MjGeom : MjShapeComponent {
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
     if (ShapeType == ShapeTypes.Mesh) {
       _geomInGlobalFrame.Set(
-          translation: MjEngineTool.UnityVector3(data->geom_xpos, MujocoId),
+          translation: MjEngineTool.UnityVector3(
-          rotation: MjEngineTool.UnityQuaternionFromMatrix(data->geom_xmat, MujocoId));
+              MjEngineTool.MjVector3AtEntry(data->geom_xpos, MujocoId)),
+          rotation: MjEngineTool.UnityQuaternionFromMatrix(
+              MjEngineTool.MjMatrixAtEntry(data->geom_xmat, MujocoId)));
       var comInGlobalFrame = _geomInGlobalFrame * _comTransform;
       comInGlobalFrame.StoreGlobal(transform);
     } else {
-      transform.position = MjEngineTool.UnityVector3(data->geom_xpos, MujocoId);
+      transform.position = MjEngineTool.UnityVector3(
-      transform.rotation = MjEngineTool.UnityQuaternionFromMatrix(data->geom_xmat, MujocoId);
+          MjEngineTool.MjVector3AtEntry(data->geom_xpos, MujocoId));
+      transform.rotation = MjEngineTool.UnityQuaternionFromMatrix(
+          MjEngineTool.MjMatrixAtEntry(data->geom_xmat, MujocoId));
     }
   }
 

unity/Runtime/Components/Shapes/MjSite.cs

@@ -40,8 +40,10 @@ public class MjSite : MjShapeComponent {
 
   // Synchronize the state of the component.
   public override unsafe void OnSyncState(MujocoLib.mjData_* data) {
-    transform.position = MjEngineTool.UnityVector3(data->site_xpos, MujocoId);
+    transform.position = MjEngineTool.UnityVector3(
-    transform.rotation = MjEngineTool.UnityQuaternionFromMatrix(data->site_xmat, MujocoId);
+        MjEngineTool.MjVector3AtEntry(data->site_xpos, MujocoId));
+    transform.rotation = MjEngineTool.UnityQuaternionFromMatrix(
+        MjEngineTool.MjMatrixAtEntry(data->site_xmat, MujocoId));
   }
 
   public void OnDrawGizmosSelected() {

unity/Runtime/Components/Tendons/MjSpatialTendon.cs

@@ -115,8 +115,10 @@ public class MjSpatialTendon : MjBaseTendon {
         if (data->wrap_obj[readHead] == -2 || data->wrap_obj[readHead + 1] == -2) {
           readHead += 1;
         } else {
-          Vector3 start = MjEngineTool.UnityVector3(data->wrap_xpos, readHead);
+          Vector3 start = MjEngineTool.UnityVector3(
-          Vector3 end = MjEngineTool.UnityVector3(data->wrap_xpos, readHead + 1);
+              MjEngineTool.MjVector3AtEntry(data->wrap_xpos, readHead));
+          Vector3 end = MjEngineTool.UnityVector3(
+              MjEngineTool.MjVector3AtEntry(data->wrap_xpos, readHead + 1));
           Gizmos.DrawLine(start, end);
           if (data->wrap_obj[readHead + 1] >= 0) { // a wrap geom
             readHead += 2;

unity/Runtime/Tools/MjEngineTool.cs

@@ -29,7 +29,6 @@ public static class MjEngineTool {
   private const int _elementsPerTransform = 7;
   private static double[] _mjQuat = new double[4];
   private static double[] _mjMat = new double[9];
-  private const int _MjSuccess = 1;
 
   public static string Sanitize(string name) {
     return name.Replace('/', '_');
@@ -71,25 +70,30 @@ public static class MjEngineTool {
   }
 
   // Stores a unity vector in a Mujoco target buffer.
-  // The vector coordinates will be stored at the 'entryIndex * 3' of the 'mjTarget' array.
+  public static unsafe void SetMjVector3(double* mjTarget, Vector3 unityVec) {
-  public static unsafe void SetMjVector3(double* mjTarget, Vector3 unityVec, int entryIndex) {
-    var startOffset = entryIndex * _elementsPerPosition;
     var mjVec = MjVector3(unityVec);
-    mjTarget[startOffset] = mjVec[0];
+    mjTarget[0] = mjVec[0];
-    mjTarget[startOffset + 1] = mjVec[1];
+    mjTarget[1] = mjVec[1];
-    mjTarget[startOffset + 2] = mjVec[2];
+    mjTarget[2] = mjVec[2];
   }
 
   // Stores a unity quaternion in a Mujoco target buffer.
-  // The vector coordinates will be stored at the 'entryIndex * 4' of the 'mjTarget' array.
+  public static unsafe void SetMjQuaternion(double* mjTarget, Quaternion unityQuat) {
-  public static unsafe void SetMjQuaternion(
-    double* mjTarget, Quaternion unityQuat, int entryIndex) {
-    var startOffset = entryIndex * _elementsPerRotation;
     var mjQuat = MjQuaternion(unityQuat);
-    mjTarget[startOffset] = mjQuat.w;
+    mjTarget[0] = mjQuat.w;
-    mjTarget[startOffset + 1] = mjQuat.x;
+    mjTarget[1] = mjQuat.x;
-    mjTarget[startOffset + 2] = mjQuat.y;
+    mjTarget[2] = mjQuat.y;
-    mjTarget[startOffset + 3] = mjQuat.z;
+    mjTarget[3] = mjQuat.z;
+  }
+
+  // Returns a pointer to an entry in the MuJoCo field that's 3*offsetEntry down the buffer.
+  public static unsafe double* MjVector3AtEntry(double* mjTarget, int offsetEntry) {
+    return mjTarget + offsetEntry * _elementsPerPosition;
+  }
+
+  // Returns a pointer to an entry in the MuJoCo field that's 4*offsetEntry down the buffer.
+  public static unsafe double* MjQuaternionAtEntry(double* mjTarget, int offsetEntry) {
+    return mjTarget + offsetEntry * _elementsPerRotation;
   }
 
   // Returns a pointer to an entry in the MuJoCo field that's 7*offsetEntry down the buffer.
@@ -97,6 +101,11 @@ public static class MjEngineTool {
     return mjTarget + offsetEntry * _elementsPerTransform;
   }
 
+  // Returns a pointer to an entry in the MuJoCo field that's 9*offsetEntry down the buffer.
+  public static unsafe double* MjMatrixAtEntry(double* mjTarget, int offsetEntry) {
+    return mjTarget + offsetEntry * _mjMat.Length;
+  }
+
   // Stores a unity transform (position+rotation) in a Mujoco target buffer.
   public static unsafe void SetMjTransform(
       double* mjTarget, Vector3 unityVec, Quaternion unityQuat) {
@@ -117,10 +126,8 @@ public static class MjEngineTool {
   }
 
   // Converts a Mujoco vector to a Unity vector.
-  public static unsafe Vector3 UnityVector3(double* coords, int entryIndex) {
+  public static unsafe Vector3 UnityVector3(double* mjVector) {
-    var startOffset = entryIndex * _elementsPerPosition;
+    return new Vector3((float)mjVector[0], (float)mjVector[2], (float)mjVector[1]);
-    return new Vector3(
-        (float)coords[startOffset], (float)coords[startOffset + 2], (float)coords[startOffset + 1]);
   }
 
   // Converts a Mujoco vector to a Unity vector.
@@ -142,21 +149,9 @@ public static class MjEngineTool {
   }
 
   // Converts a Mujoco quaternion to a Unity quaternion.
-  // The quaternions is read starting at 'entryIndex * 4' of the 'coords' array.
+  public static unsafe Quaternion UnityQuaternion(double* mjQuat) {
-  public static Quaternion UnityQuaternion(double[] coords, int entryIndex) {
-    var startOffset = entryIndex * _elementsPerRotation;
     return new Quaternion(
-        x:(float)coords[startOffset + 1], y:(float)coords[startOffset + 3],
+        x:(float)mjQuat[1], y:(float)mjQuat[3], z:(float)mjQuat[2], w:(float)-mjQuat[0]);
-        z:(float)coords[startOffset + 2], w:(float)-coords[startOffset]);
-  }
-
-  // Converts a Mujoco quaternion to a Unity quaternion.
-  // The quaternion is read starting at 'entryIndex * 4' of the 'coords' array.
-  public static unsafe Quaternion UnityQuaternion(double* coords, int entryIndex) {
-    var startOffset = entryIndex * _elementsPerRotation;
-    return new Quaternion(
-        x:(float)coords[startOffset + 1], y:(float)coords[startOffset + 3],
-        z:(float)coords[startOffset + 2], w:(float)-coords[startOffset]);
   }
 
   // Converts a Mujoco quaternion to a Unity quaternion.
@@ -166,17 +161,16 @@ public static class MjEngineTool {
   }
 
   // Converts a Mujoco matrix to a Unity quaternion.
-  // The matrix coordinates are at the 'entryIndex * 9' of the 'coords' array.
+  // The matrix coordinates are at the 'entryIndex * 9' of the 'mjMat' array.
-  public static unsafe Quaternion UnityQuaternionFromMatrix(double* coords, int entryIndex) {
+  public static unsafe Quaternion UnityQuaternionFromMatrix(double* mjMat) {
-    var startOffset = entryIndex * _mjMat.Length;
     for (var j = 0; j < _mjMat.Length; ++j) {
-      _mjMat[j] = coords[startOffset + j];
+      _mjMat[j] = mjMat[j];
     }
-    fixed (double* a = _mjQuat)
+    fixed (double* q_out = _mjQuat)
-    fixed (double* b = _mjMat) {
+    fixed (double* m_in = _mjMat) {
-      MujocoLib.mju_mat2Quat(a, b);
+      MujocoLib.mju_mat2Quat(q_out, m_in);
+      return UnityQuaternion(q_out);
     }
-    return UnityQuaternion(_mjQuat, 0);
   }
 
   // Converts a Unity extents Vector3 to a Mujoco extents vector.

unity/Tests/Editor/Tools/MjEngineTests.cs

@@ -47,7 +47,8 @@ namespace Mujoco {
       var MjVec = MjEngineTool.MjVector3(vec);
       var MjVecAsArray = new double[] { 10, 11, 12, MjVec.x, MjVec.y, MjVec.z };
       fixed (double* MjArrPtr = MjVecAsArray) {
-        var recreatedVec = MjEngineTool.UnityVector3(MjArrPtr, 1);
+        var recreatedVec = MjEngineTool.UnityVector3(
+            MjEngineTool.MjVector3AtEntry(MjArrPtr, 1));
         Assert.That(recreatedVec, Is.EqualTo(vec));
       }
     }
@@ -64,23 +65,6 @@ namespace Mujoco {
       Assert.That(unityVec, Is.EqualTo(vec));
     }
 
-    [TestCase(0.1f, 0.2f, 0.3f, 0.4f)]
-    [TestCase(-0.1f, -0.2f, -0.3f, -0.4f)]
-    [TestCase(-0.1f, 0.2f, 0.3f, 0.4f)]
-    [TestCase(0.1f, -0.2f, 0.3f, 0.4f)]
-    [TestCase(0.1f, 0.2f, -0.3f, 0.4f)]
-    [TestCase(0.1f, 0.2f, 0.3f, -0.4f)]
-    public unsafe void RoundrobinConversionOfQuaternion(float x, float y, float z, float w) {
-      var quat = new Quaternion(x, y, z, w);
-      var MjQuat = MjEngineTool.MjQuaternion(quat);
-      var MjQuatAsArray =
-          new double[] { 10, 20, 30, 40, MjQuat.w, MjQuat.x, MjQuat.y, MjQuat.z };
-      var recreatedQuat = MjEngineTool.UnityQuaternion(MjQuatAsArray, 1);
-      var q1 = new Vector4(quat.x, quat.y, quat.z, quat.w);
-      var q2 = new Vector4(recreatedQuat.x, recreatedQuat.y, recreatedQuat.z, recreatedQuat.w);
-      Assert.That(q1, Is.EqualTo(q2));
-    }
-
     [TestCase(0.1f, 0.2f, 0.3f, 0.4f)]
     [TestCase(-0.1f, -0.2f, -0.3f, -0.4f)]
     [TestCase(-0.1f, 0.2f, 0.3f, 0.4f)]
@@ -94,7 +78,8 @@ namespace Mujoco {
       var MjQuatAsArray =
           new double[] { 10, 20, 30, 40, MjQuat.w, MjQuat.x, MjQuat.y, MjQuat.z };
       fixed (double* MjArrPtr = MjQuatAsArray) {
-        var recreatedQuat = MjEngineTool.UnityQuaternion(MjArrPtr, 1);
+        var recreatedQuat = MjEngineTool.UnityQuaternion(
+            MjEngineTool.MjQuaternionAtEntry(MjArrPtr, 1));
         var q1 = new Vector4(quat.x, quat.y, quat.z, quat.w);
         var q2 = new Vector4(recreatedQuat.x, recreatedQuat.y, recreatedQuat.z, recreatedQuat.w);
         Assert.That(q1, Is.EqualTo(q2));
@@ -138,8 +123,8 @@ namespace Mujoco {
       var result = Quaternion.identity;
       var buffer = new double[4];
       fixed (double* unsafeBuffer = buffer) {
-        MjEngineTool.SetMjQuaternion(unsafeBuffer, quat, entryIndex: 0);
+        MjEngineTool.SetMjQuaternion(unsafeBuffer, quat);
-        result = MjEngineTool.UnityQuaternion(unsafeBuffer, entryIndex: 0);
+        result = MjEngineTool.UnityQuaternion(unsafeBuffer);
       }
       Assert.That(quat, Is.EqualTo(result));
     }
@@ -154,8 +139,8 @@ namespace Mujoco {
       var result = Vector3.zero;
       double[] buffer = new double[3];
       fixed (double* unsafeBuffer = buffer) {
-        MjEngineTool.SetMjVector3(unsafeBuffer, vec, entryIndex: 0);
+        MjEngineTool.SetMjVector3(unsafeBuffer, vec);
-        result = MjEngineTool.UnityVector3(unsafeBuffer, entryIndex: 0);
+        result = MjEngineTool.UnityVector3(unsafeBuffer);
       }
       Assert.That(vec, Is.EqualTo(result));
     }

unity/Tests/Runtime/MjSensorPlayTests.cs

@@ -0,0 +1,123 @@
+// Copyright 2019 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#if UNITY_EDITOR
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Xml;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+using UnityEngine.TestTools.Utils;
+
+namespace Mujoco {
+
+[TestFixture]
+public class MjSensorPlayTests {
+  private MjBody _body;
+  private MjSite _site;
+  private MjGeom _geom;
+  private MjHingeJoint _joint;
+  private MjSiteQuaternionSensor _siteQuatSensor0;
+  private MjSiteQuaternionSensor _siteQuatSensor;
+  private MjSiteVectorSensor _siteVectorSensor;
+  private MjGeomQuaternionSensor _geomQuatSensor;
+  private MjGeomVectorSensor _geomVectorSensor;
+  private MjBodyQuaternionSensor _bodyQuatSensor;
+  private MjBodyVectorSensor _bodyVectorSensor;
+  private MjScene _scene;
+
+  [SetUp]
+  public void SetUp() {
+    _scene = MjScene.Instance;
+    _body = new GameObject("body").AddComponent<MjBody>();
+    _site = new GameObject("site").AddComponent<MjSite>();
+    _geom = new GameObject("geom").AddComponent<MjGeom>();
+    _siteQuatSensor0 = new GameObject("sq0").AddComponent<MjSiteQuaternionSensor>();
+    _siteQuatSensor0.Site = _site;
+    _siteQuatSensor = new GameObject("sq").AddComponent<MjSiteQuaternionSensor>();
+    _siteQuatSensor.Site = _site;
+    _siteVectorSensor = new GameObject("sv").AddComponent<MjSiteVectorSensor>();
+    _siteVectorSensor.Site = _site;
+    _siteVectorSensor.SensorType = MjSiteVectorSensor.AvailableSensors.FramePos;
+    _geomQuatSensor = new GameObject("gq").AddComponent<MjGeomQuaternionSensor>();
+    _geomQuatSensor.Geom = _geom;
+    _geomVectorSensor = new GameObject("gv").AddComponent<MjGeomVectorSensor>();
+    _geomVectorSensor.Geom = _geom;
+    _geomVectorSensor.SensorType = MjGeomVectorSensor.AvailableSensors.FramePos;
+    _bodyQuatSensor = new GameObject("bq").AddComponent<MjBodyQuaternionSensor>();
+    _bodyQuatSensor.Body = _body;
+    _bodyVectorSensor = new GameObject("bv").AddComponent<MjBodyVectorSensor>();
+    _bodyVectorSensor.Body = _body;
+    _bodyVectorSensor.SensorType = MjBodyVectorSensor.AvailableSensors.FramePos;
+    _site.transform.position = new Vector3(1, 2, 3);
+    _site.transform.rotation = new Quaternion(0, 1, 2, 3);
+    _geom.transform.position = new Vector3(4, 5, 6);
+    _geom.transform.rotation = new Quaternion(4, 5, 6, 7);
+    _body.transform.position = new Vector3(7, 8, 9);
+    _body.transform.rotation = new Quaternion(7, 8, 9, 9);
+    _scene.CreateScene(); // compilation happens here
+  }
+
+  [TearDown]
+  public void TearDown() {
+    GameObject.DestroyImmediate(_site.gameObject);
+    GameObject.DestroyImmediate(_body.gameObject);
+    GameObject.DestroyImmediate(_geom.gameObject);
+    GameObject.DestroyImmediate(_siteQuatSensor0.gameObject);
+    GameObject.DestroyImmediate(_siteQuatSensor.gameObject);
+    GameObject.DestroyImmediate(_siteVectorSensor.gameObject);
+    GameObject.DestroyImmediate(_geomQuatSensor.gameObject);
+    GameObject.DestroyImmediate(_geomVectorSensor.gameObject);
+    GameObject.DestroyImmediate(_bodyQuatSensor.gameObject);
+    GameObject.DestroyImmediate(_bodyVectorSensor.gameObject);
+    GameObject.DestroyImmediate(_scene.gameObject);
+    GameObject.DestroyImmediate(MjScene.Instance);
+  }
+
+  [UnityTest]
+  public IEnumerator CheckSensorData() {
+    yield return new WaitForFixedUpdate(); // updating the transform
+    yield return new WaitForFixedUpdate(); // updating the transform
+    var vecComparer = new Vector3EqualityComparer(1e-4f);
+    var quatComparer = new Vector4EqualityComparer(1e-4f);
+    Assert.That(
+        _siteVectorSensor.SensorReading,
+        Is.EqualTo(_site.transform.position).Using(vecComparer));
+    Assert.That(
+        _geomVectorSensor.SensorReading,
+        Is.EqualTo(_geom.transform.position).Using(vecComparer));
+    Assert.That(
+        _bodyVectorSensor.SensorReading,
+        Is.EqualTo(_body.transform.position).Using(vecComparer));
+
+    Assert.That(
+        _siteQuatSensor0.SensorReading,
+        Is.EqualTo(_site.transform.rotation.normalized).Using(quatComparer));
+    Assert.That(
+        _siteQuatSensor.SensorReading,
+        Is.EqualTo(_site.transform.rotation.normalized).Using(quatComparer));
+    Assert.That(
+        _geomQuatSensor.SensorReading,
+        Is.EqualTo(_geom.transform.rotation.normalized).Using(quatComparer));
+    Assert.That(
+        _bodyQuatSensor.SensorReading,
+        Is.EqualTo(_body.transform.rotation.normalized).Using(quatComparer));
+  }
+}
+}
+
+#endif

unity/Tests/Runtime/MjSensorPlayTests.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 62bfed53c131e77cfa2845ad38c35a4e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: