Trouble with RigidBody2D add torque.

Hi everyone, I'm creating unity tests to verify that the way I apply forces to my objects is correct in Unity 2019.1.10f1.

I cannot seem to get the RigidBody2D.addTorque right in my classes. When that identical setup works for add force.

In my unity test in play mode, I create a RigidBody2D and make sure that gravity is not applied to it and that angular drag is 0.
Therefore my RigidBody has an inertia of 1 which is the default.
Here is the setup code

Code (CSharp):

1. [OneTimeSetUp]
2. public void Init()
3. {
4.     //Init runs once before running test cases.
5.     go = new GameObject();
6.     rb = go.AddComponent<Rigidbody2D>();
7.     // Don't forget this, it seems like gravity is not the same as the
8.     // Project settings.
9.     rb.gravityScale = 0;
10.     rb.angularDrag = 0;
11. }
12.  
13.  
14. [SetUp]
15. public void SetUp()
16. {
17.     //SetUp runs before all test cases
18.     rb.velocity = Vector2.zero;
19.     rb.angularVelocity = 0;
20.     rb.position = Vector2.zero;
21.     rb.rotation = 0;
22.  
23. }

I would expect that if I apply a force of 50 N.m and my FixedDelta time is 0.02s, my rotational speed would be of 1 degree per second after that force has been applied and that the tick has passed.

I then apply a torque the following way :

Code (CSharp):

1. [UnityTest]
2. public IEnumerator RotationTest2()
3. {
4. Debug.Log($"Initial angular speed is : {rb.angularVelocity}.");
5. rb.AddTorque(50, ForceMode2D.Force);
6. yield return null; // do simulation frame
7.  
8. Debug.Log($"Angular acceleration is : {50}.");
9. Debug.Log($"Final angular speed is : {rb.angularVelocity}.");
10. Debug.Log($"Expected angular speed is : {50 * Time.fixedDeltaTime / rb.inertia}.");
11. Assert.Less(Mathf.Abs(rb.angularVelocity - 50 * Time.fixedDeltaTime / rb.inertia)), 0.00001f);
12. }

The output of my unit test is the following :
Initial angular speed is : 0.
Angular acceleration is : 50.
Final angular speed is : 57.29578.
Expected angular speed is : 1.

Does someone see the mistake that I am currently doing?

Thank you in advance guys!
Elliot.

 

Could someone please confirm that they also get the angular speed I have on their version?

Steps to replicate :

• Create new project
• In assets menu : Create>Testing>Test assembly folder
• Paste the attached script in the created folder
• Run it with the test runnner that can be opened in Window>general>TestRunner

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using NUnit.Framework;
4. using UnityEngine;
5. using UnityEngine.TestTools;
6.  
7. /// <summary>
8. /// Testing the unity engine Physics2D
9. /// </summary>
10. namespace Tests
11. {
12.     public class RigidBodyTest
13.     {
14.         /// <summary>
15.         /// Game object on which we test the engine
16.         /// </summary>
17.         GameObject go;
18.         /// <summary>
19.         /// Rigid body 2D instance to test the engine with
20.         /// </summary>
21.         Rigidbody2D rb;
22.  
23.  
24.         [OneTimeSetUp]
25.         public void Init()
26.         {
27.             //Init runs once before running test cases.
28.             go = new GameObject();
29.             rb = go.AddComponent<Rigidbody2D>();
30.             // Don't forget this, it seems like gravity is not the same as the
31.             // Project settings.
32.             rb.gravityScale = 0;
33.             rb.angularDrag = 0;
34.         }
35.  
36.  
37.         [SetUp]
38.         public void SetUp()
39.         {
40.             //SetUp runs before all test cases
41.             rb.velocity = Vector2.zero;
42.             rb.angularVelocity = 0;
43.             rb.position = Vector2.zero;
44.             rb.rotation = 0;
45.  
46.         }
47.  
48.         [UnityTest]
49.         public IEnumerator RotationTest()
50.         {
51.             Debug.Log($"Initial angular speed is : {rb.angularVelocity}.");
52.             rb.AddTorque(50, ForceMode2D.Force);
53.             yield return null; // do simulation frame
54.  
55.             Debug.Log($"Angular acceleration is : {50}");
56.             Debug.Log($"Final angular speed is : {rb.angularVelocity}");
57.             Debug.Log($"Expected angular speed is : {50 * Time.fixedDeltaTime / rb.inertia}");
58.             Assert.Less(Mathf.Abs(rb.angularVelocity - 50 * Time.fixedDeltaTime / rb.inertia), 0.00001f);
59.         }
60.     }
61. }
62.  

 

Solved by this https://forum.unity.com/threads/torque-and-inertia-in-rigidbody2d-scripting-manual.381234/