ML-Agents-Examples: add two extra legs to crawler -> IndexOutOfRangeException

Hey guys,

I want to add two extra legs to the crawler and then train it. I added the legs in the Unity-Editor.





Then I added the following lines of code:

Code (CSharp):

1. [Header("Body Parts")] [Space(10)] public Transform body;
2.     public Transform leg0Upper;
3.     public Transform leg0Lower;
4.     public Transform leg1Upper;
5.     public Transform leg1Lower;
6.     public Transform leg2Upper;
7.     public Transform leg2Lower;
8.     public Transform leg3Upper;
9.     public Transform leg3Lower;
10.     public Transform leg4mUpper;
11.     public Transform leg4mLower;
12.     public Transform leg5mUpper;
13.     public Transform leg5mLower;
14.  

Code (CSharp):

1.     public override void Initialize()
2.     {
3.         m_JdController = GetComponent<JointDriveController>();
4.         m_DirToTarget = target.position - body.position;
5.  
6.  
7.         //Setup each body part
8.         m_JdController.SetupBodyPart(body);
9.         m_JdController.SetupBodyPart(leg0Upper);
10.         m_JdController.SetupBodyPart(leg0Lower);
11.         m_JdController.SetupBodyPart(leg1Upper);
12.         m_JdController.SetupBodyPart(leg1Lower);
13.         m_JdController.SetupBodyPart(leg2Upper);
14.         m_JdController.SetupBodyPart(leg2Lower);
15.         m_JdController.SetupBodyPart(leg3Upper);
16.         m_JdController.SetupBodyPart(leg3Lower);
17.         m_JdController.SetupBodyPart(leg4mUpper);
18.         m_JdController.SetupBodyPart(leg4mLower);
19.         m_JdController.SetupBodyPart(leg5mUpper);
20.         m_JdController.SetupBodyPart(leg5mLower);
21.     }

The code executed fine and the crawler was also still able to still walk a bit (with the pre-learned net for four legs). But when I added that:

Code (CSharp):

1.     public override void OnActionReceived(float[] vectorAction)
2.     {
3.         // The dictionary with all the body parts in it are in the jdController
4.         var bpDict = m_JdController.bodyPartsDict;
5.  
6.         var i = -1;
7.         // Pick a new target joint rotation
8.         bpDict[leg0Upper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
9.         bpDict[leg1Upper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
10.         bpDict[leg2Upper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
11.         bpDict[leg3Upper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
12.         bpDict[leg4mUpper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
13.         bpDict[leg5mUpper].SetJointTargetRotation(vectorAction[++i], vectorAction[++i], 0);
14.         bpDict[leg0Lower].SetJointTargetRotation(vectorAction[++i], 0, 0);
15.         bpDict[leg1Lower].SetJointTargetRotation(vectorAction[++i], 0, 0);
16.         bpDict[leg2Lower].SetJointTargetRotation(vectorAction[++i], 0, 0);
17.         bpDict[leg3Lower].SetJointTargetRotation(vectorAction[++i], 0, 0);
18.         bpDict[leg4mLower].SetJointTargetRotation(vectorAction[++i], 0, 0);
19.         bpDict[leg5mLower].SetJointTargetRotation(vectorAction[++i], 0, 0);
20.  
21.         // Update joint strength
22.         bpDict[leg0Upper].SetJointStrength(vectorAction[++i]);
23.         bpDict[leg1Upper].SetJointStrength(vectorAction[++i]);
24.         bpDict[leg2Upper].SetJointStrength(vectorAction[++i]);
25.         bpDict[leg3Upper].SetJointStrength(vectorAction[++i]);
26.         bpDict[leg4mUpper].SetJointStrength(vectorAction[++i]);
27.         bpDict[leg5mUpper].SetJointStrength(vectorAction[++i]);
28.         bpDict[leg0Lower].SetJointStrength(vectorAction[++i]);
29.         bpDict[leg1Lower].SetJointStrength(vectorAction[++i]);
30.         bpDict[leg2Lower].SetJointStrength(vectorAction[++i]);
31.         bpDict[leg3Lower].SetJointStrength(vectorAction[++i]);
32.         bpDict[leg4mLower].SetJointStrength(vectorAction[++i]);
33.         bpDict[leg5mLower].SetJointStrength(vectorAction[++i]);
34.     }

I get the following error:

IndexOutOfRangeException: Index was outside the bounds of the array.
CrawlerAgent.OnActionReceived (System.Single[] vectorAction) (at Assets/ML-Agents/Examples/Crawler/Scripts/CrawlerAgent.cs:181)
MLAgents.Agent.AgentStep () (at /Users/Johannes/ml-agents/com.unity.ml-agents/Runtime/Agent.cs:793)
MLAgents.Academy.EnvironmentStep () (at /Users/Johannes/ml-agents/com.unity.ml-agents/Runtime/Academy.cs:472)
MLAgents.AcademyFixedUpdateStepper.FixedUpdate () (at /Users/Johannes/ml-agents/com.unity.ml-agents/Runtime/Academy.cs:34)

(line 181 in CrawlerAgent refers to the line where the 17th element is added)

I think that the bpDict is too small, but I do not understand, where I can change that.
If anybody knows, please let me know!
(Also if you there is some other misconception)

Greetings,
Johannes

 

I just did, the crawler is learning now. Thank you!