Applying force to a rigidbody relative to the direction of another GameObject and player input

Hi,

So as the title suggests, I'm looking to find a way to add force to a rigid-body, based on the direction of another object, using player input. For example, if the player pressed w then it would move towards the forward direction the other game object is looking. Same for a, s and d respectively.

This is what I have so far. Please note that is is designed to work in VR hence the first two lines. This shouldn't affect the input as I am using D-pad input.

Code (CSharp):

1. //Set size and position of the capsule collider so it maches our head.
2.         Collider.height = Head.transform.localPosition.y;
3.         Collider.center = new Vector3(Head.transform.localPosition.x, Head.transform.localPosition.y / 2, Head.transform.localPosition.z);
4.  
5.         moveDirection = new Vector3(0, 0, 0);//(Head.transform.forward*trackpad);
6.         if (StandardisedControlScript.Dpad(Hand, "w"))
7.         {
8.             moveDirection = new Vector3(moveDirection.x+1, moveDirection.y, moveDirection.z);
9.         }
10.         if (StandardisedControlScript.Dpad(Hand, "a"))
11.         {
12.             moveDirection = new Vector3(moveDirection.x, moveDirection.y, moveDirection.z+1);
13.         }
14.         if (StandardisedControlScript.Dpad(Hand, "s"))
15.         {
16.             moveDirection = new Vector3(moveDirection.x-1, moveDirection.y, moveDirection.z);
17.         }
18.         if (StandardisedControlScript.Dpad(Hand, "d"))
19.         {
20.             moveDirection = new Vector3(moveDirection.x, moveDirection.y, moveDirection.z-1);
21.         }
22.         gameObject.transform.rotation = Quaternion.Euler(new Vector3(0, Head.transform.rotation.y, 0));
23.         Debug.Log(moveDirection);
24.         updateInput();
25.         //GetComponent<Rigidbody>().MoveRotation(Quaternion.Euler(new Vector3(0, Head.transform.rotation.y, 0)));
26.         GetComponent<Rigidbody>().velocity = new Vector3(GetComponent<Rigidbody>().velocity.x/2, GetComponent<Rigidbody>().velocity.y, GetComponent<Rigidbody>().velocity.z / 2);
27.         GetComponent<Rigidbody>().AddRelativeForce(moveDirection * accellSpeed);

Any help will be appreciated. I've tried using AddForce and AddRelative force but despite much googling, I'm not sure I have been implementing them correctly.

If you need more info on anything, please ask and I'll get back to you ASAP

 

Hi JamesGamesInc,

I've made a small demo script for this. Tell me if you have difficulty using it, or it's not quite what you want.

Cheers.

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.SceneManagement;
3.  
4. public class GameManager : MonoBehaviour
5. {
6.     [SerializeField]
7.     private KeyCode resetSceneKeyCode;
8.  
9.     [SerializeField]
10.     private KeyCode verticalMovementKeyCode;
11.  
12.     [SerializeField]
13.     private KeyCode directionInputKeyCode;
14.  
15.     [SerializeField]
16.     private KeyCode rollKeyCode;
17.  
18.     [SerializeField]
19.     private Transform directionTransform;
20.  
21.     [SerializeField]
22.     private Rigidbody movingRigidbody;
23.  
24.     [SerializeField]
25.     private float movementForceScale;
26.  
27.     [SerializeField]
28.     private ForceMode movementForceMode;
29.  
30.     [SerializeField]
31.     private float directionInputScale;
32.  
33.     private Vector3 movementVector;
34.  
35.     private Vector3 directionInput;
36.  
37.     private void Update()
38.     {
39.         UpdateInput();
40.         UpdateRotation();
41.     }
42.  
43.     private void FixedUpdate()
44.     {
45.         var direction = directionTransform.TransformDirection(movementVector);
46.  
47.         movingRigidbody.AddForce(
48.             direction * movementForceScale,
49.             movementForceMode);
50.     }
51.  
52.     private void UpdateRotation()
53.     {
54.         directionTransform.Rotate(
55.             directionInput * directionInputScale * Time.deltaTime,
56.             Space.World);
57.     }
58.  
59.     private void UpdateInput()
60.     {
61.         UpdateResetInput();
62.  
63.         if (Input.GetKey(directionInputKeyCode))
64.         {
65.             movementVector = Vector3.zero;
66.             UpdateDirectionInput();
67.         }
68.         else
69.         {
70.             directionInput = Vector3.zero;
71.             UpdateMovementInput();
72.         }
73.     }
74.  
75.     private void UpdateResetInput()
76.     {
77.         if (Input.GetKey(resetSceneKeyCode))
78.         {
79.             SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
80.         }
81.     }
82.  
83.     private void UpdateMovementInput()
84.     {
85.         movementVector.x = Input.GetAxisRaw("Horizontal");
86.  
87.         var isVerticalMovementKeyDown = Input.GetKey(verticalMovementKeyCode);
88.         var verticalInputAxis = Input.GetAxisRaw("Vertical");
89.         movementVector.y = isVerticalMovementKeyDown ? verticalInputAxis : 0;
90.         movementVector.z = isVerticalMovementKeyDown ? 0 : verticalInputAxis;
91.     }
92.  
93.     private void UpdateDirectionInput()
94.     {
95.         directionInput.x = Input.GetAxisRaw("Vertical");
96.  
97.         var isRollKeyDown = Input.GetKey(rollKeyCode);
98.         var rollInputAxis = Input.GetAxisRaw("Horizontal");
99.         directionInput.z = isRollKeyDown ? -rollInputAxis : 0;
100.         directionInput.y = isRollKeyDown ? 0 : rollInputAxis;
101.     }
102. }

 

Works a treat. I'll go about converting it to work with my current system etc and let you know if there are any issues. Thanks for putting in the time to write that up

 

Good to hear Fixed a small bug, one of the KeyCodes was still hard-coded. Maybe someone else will also find this of use.