Animal AI random movements

Hi, I'm very new to Unity3D but have got the hang of the basic map design and animations etc, how ever I can't find any tutorials anywhere which follow similar lines to animating animals to have random movements, such as hostile mobs.

Could anyone either tell me what I could do or point me to a Tutorial.

Thanks

 

I found a wander script on the Unity wiki some time ago that should give you the basic movement: http://wiki.unity3d.com/index.php/Wander

 

Thank you so much!, it worked!!!

 

Think about it, you need the animal to move to a random position, then maybe wait for some time and then move again. While doing these, you need it to animate. So, you first need to figure out how to move the animals. Couple of ways :

- Translate Movement / Move Towards Function / Linear Interpolation
- Navmesh Agent Movement
- Rigidbody Movement

I would suggest Translate Movement, Lerp for now, actually after I tell you the logic and give some code, it won't differ too much how you make the movement, the tricky part is to actually pick the movement position. Since all of these movement types require a position, then it won't be a problem to change the movement type. Now you need a random position right ? So we need to define a radius for it. Again, couple of ways :

- There is something called Random.insideUnitCircle, it is a Vector2 and it picks random position in X and Y axis. You can use this to create a random position.
- Manually creating your random position by Random.Range.

I'll go with the second one. Another thing is, if you want your animals to wait for some time when a random position is reached, you can use a coroutine for creating a delay.

Code (CSharp):

1. public float speed;
2. public float randomX;
3. public float randomZ;
4. public float minWaitTime;
5. public float maxWaitTime;
6. private Vector3 currentRandomPos;
7.  
8.  
9. void Start()
10. {
11. PickPosition();
12. }
13.  
14. void PickPosition()
15. {
16. currentRandomPos = new Vector3(Random.Range(-randomX, randomX), 0, Random.Range(-randomZ, randomZ);
17. StartCoroutine ( MoveToRandomPos());
18.  
19. }
20.  
21. IEnumerator MoveToRandomPos()
22. {
23. float i = 0.0f;
24. float rate = 1.0f / speed;
25. Vector3 currentPos = transform.position;
26.  
27. while (i < 1.0f)
28. {
29. i += Time.deltaTime * rate;
30. transform.position = Vector3.Lerp( currentPos, currendRandomPos, i);
31. yield return null;
32. }
33.  
34. float randomFloat = Random.Range(0.0f,1.0f); // Create %50 chance to wait
35. if(randomFloat < 0.5f)
36. StartCoroutine ( WaitForSomeTime());
37. else
38. PickPosition();
39. }
40.  
41. IEnumerator WaitForSomeTime()
42. {
43. yield return new WaitForSeconds(Random.Range(minWaitTime, maxWaitTime);
44. PickPosition();
45. }

You can also search & learn Animator, and set it's parameters while moving, waiting and create your animations by it.
Hope that the logic is helpful, have a nice day !

 

Hi casper!

I'm a complete beginner as well at this and was wondering if you could help me out for a minute? Do I simply download the wander script and attach it to an animal GameObject in my scene to make it wander randomly?

Thanks

 

This didn't seem to work for me... Here's my script:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class AnimalMovement : MonoBehaviour
6. {
7.     Animator anim;
8.  
9.     [SerializeField]
10.     private float speed;
11.     [SerializeField]
12.     private float randomX;
13.     [SerializeField]
14.     private float randomZ;
15.     [SerializeField]
16.     private float minWaitTime;
17.     [SerializeField]
18.     private int maxWaitTime;
19.  
20.     private Vector3 currentRandomPos;
21.  
22.     // Start is called before the first frame update
23.     void Start()
24.     {
25.         speed -= anim.GetFloat("Speed");
26.  
27.         anim = GetComponent<Animator>();
28.  
29.         PickPosition();
30.     }
31.  
32.     // Update is called once per frame
33.     void Update()
34.     {
35.  
36.     }
37.  
38.     void PickPosition()
39.     {
40.         currentRandomPos = new Vector3(Random.Range(-randomX, randomX), 0, Random.Range(-randomZ, randomZ));
41.         StartCoroutine(MoveToRandomPos());
42.     }
43.  
44.     IEnumerator MoveToRandomPos()
45.     {
46.         float i = 0.0f;
47.         float rate = 1.0f / speed;
48.         Vector3 currentPos = transform.position;
49.  
50.         while (i < 1.0f)
51.         {
52.             i += Time.deltaTime * rate;
53.             transform.position = Vector3.Lerp(currentPos, currentRandomPos, i);
54.             yield return null;
55.         }
56.  
57.         float randomFloat = Random.Range(0.0f, 1.0f);
58.        
59.         if(randomFloat < 0.5f)
60.         {
61.             StartCoroutine(WaitForSomeTime());
62.         }
63.  
64.         IEnumerator WaitForSomeTime()
65.         {
66.             yield return new WaitForSeconds(Random.Range(minWaitTime, maxWaitTime));
67.             PickPosition();
68.         }
69.     }
70. }

Do you see any problems in it? If you do, please let me know. Also, does anybody know how I can use one animation controller for every animal (the animals are made myself using the "animation" window.)

 

I wonder if there is a special NavMeshAgent for animals and non-human forms?

 

No. NavMeshAgents are very generic, very low level scripts, they aren't show any behavior other than following a path. So why would they have different?