Moving on a grid in first person. Forward, Backward, Strafing, and rotating

Hey all, I've suddenly found myself thrust back into unity development and have hit a bit of a road block on the basics.

I have a first person camera that I'm going to have moving around in a ridged grid. Where you can move one block forward, backward, strafe left and right. But you can also pivot in place in 90 degree intervals to change your heading. I figured out the directional stuff (sort of), but I'm having serious trouble with rotating.

here's my Javascript movement code so far....

Code (JavaScript):

1. private var speed = 10.0;
2. private var pos : Vector3;
3. private var tr : Transform;
4. private var rot : Quaternion;
5. public var rotSpeed = 140.0;
6.  
7.  
8. function Start () {
9.     pos = transform.position;
10.     tr = transform;
11.     rot = transform.rotation;
12. }
13.  
14. function Update () {
15.  
16.  
17.     if (Input.GetKeyDown(KeyCode.E) && tr.position == pos) {
18.         pos += Vector3(5,0,0); //right
19.     }
20.     else if (Input.GetKeyDown(KeyCode.Q) && tr.position == pos) {
21.         pos += Vector3(-5,0,0); //left
22.     }
23.     else if (Input.GetKeyDown(KeyCode.W) && tr.position == pos) {
24.         pos += Vector3(0,0,5); //forward  
25.     }
26.     else if (Input.GetKeyDown(KeyCode.S) && tr.position == pos) {
27.         pos += Vector3(0,0,-5); //backward
28.     }
29.     else if (Input.GetKeyDown(KeyCode.D) && tr.position == pos) {
30.         rot = Quaternion.Euler (0,90,0); // rotate right
31.     }
32.     else if (Input.GetKeyDown(KeyCode.A) && tr.position == pos) {
33.         rot = Quaternion.Euler (0,-90,0); // rotate left
34.     }
35.  
36.     transform.rotation = Quaternion.RotateTowards (transform.rotation, rot, Time.deltaTime * rotSpeed);
37.     transform.position = Vector3.MoveTowards(transform.position, pos, Time.deltaTime * speed);
38. }

I'm getting the snappy grid based movement I want, but rotating just isn't working. Instead of turning 90 degrees left or right in increments its just setting the rotation angle to 90 or -90 degrees. Clearly I should be adding or subtracting to some value, but I can't for the life of me figure out how to find it, or set it properly (damn you Quaternions!).

This is of course leading to a bigger problem very soon, as rotating doesn't change the directional movement orientation based on the direction my camera is looking. W still moves on the Z axis etc... Will I need to code a bunch of if/then checks to reorient at every angle?

Thanks for any help or suggestions you might have for me.

 

I have instant turn method as:

Code (CSharp):

1.  
2.     public void Turn( bool left )
3.     {
4.         if ( !left )
5.             transform.Rotate( 0, 90, 0, Space.Self );
6.         else
7.             transform.Rotate( 0, -90, 0, Space.Self );
8.     }
9.  

and moving needs to have its direction translated from local to world with:

Code (CSharp):

1.  
2. Vector3 worldDirection = transform.TransformDirection( direction );
3.  

direction would propably be equal to 'pos' in your code.

Hopes this will help you right direction

 

I guess I'm unclear on some things, plugging in your rotate commands work for proper 360 rotation, but its instantanious when I'm looking for a smooth transition over deltatime. (like how transform.position= Vector3.MoveTowards(transform.position, pos, Time.deltaTime* speed); does it for stepping in directions)

worldDirection looks really useful, but I have no idea where to enter it into my code so its relevant. Could you clarify?

 

Try something like this:

Code (CSharp):

1.  
2. var dir;
3. ///some lines between
4.    if (Input.GetKeyDown(KeyCode.E) ) {
5.         dir= -Vector3.left; //right
6. ///and below
7. //edit 'Damn mobile'
8. Insert the line with worldPosition here
9.  
10.  
11. transform.position = Vector3.MoveTowards(transform.position, worldDirection *5 , Time.deltaTime * speed);
12.  

I'm throwing these from the top of my head as I'm not at my dev computer.
Rotation probably needs similar local to world conversion.

 

Rotations can be multiplied to add them together. So if you do:

Code (CSharp):

1. transform.rotation = transform.rotation * Quaternion.Euler(0, 90, 0);

That would rotate your character 90 degrees to the right of it's current rotation.

which means that you'll want to replace:

Code (javascript):

1. rot = Quaternion.Euler(0,90,0);// rotate right

with this:

Code (javascript):

1. rot = rot * Quaternion.Euler(0,90,0);// rotate right

and you should be good.

 

Thx Baste for that.
Did you get it to work The_Adventurer?
Here's mine a bit modified playerMove script ( I have separate script for input etc.. )
It's in Csharp but I'm sure you can manage to modify it to unityScript.

Code (CSharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class PlayerMovementMod : MonoBehaviour
6. {
7.  
8.     public float gridSize;
9.  
10.     public float moveSpeed = 15;
11.     public float rotationSpeed = 300f;
12.  
13.     public Vector3 position;
14.     public Quaternion rotation;
15.  
16.     public void Turn( bool left )
17.     {
18.         if ( isAnimating() )
19.             return;
20.         if ( !left )
21.             rotation = rotation * Quaternion.Euler( 0, 90, 0 );
22.         else
23.             rotation = rotation * Quaternion.Euler( 0, -90, 0 );
24.     }
25.  
26.     private void Move( Vector3 dir )
27.     {
28.         //Translates direction from local to world
29.         Vector3 worldDirection = transform.TransformDirection( dir );
30.  
31.         if ( isFreeTile( worldDirection ) )
32.         {
33.             position = worldDirection * gridSize + transform.position;
34.         }
35.     }
36.  
37.  
38.     private bool isFreeTile( Vector3 worldDirection )
39.     {
40.    
41.         RaycastHit hit;
42.  
43.         //Debug.DrawLine( transform.position, transform.position + worldDirection * gridSize, Color.red, 1f );
44.  
45.         if ( Physics.Raycast( transform.position, worldDirection, out hit, gridSize ) )
46.         {
47.             Debug.Log( "Bump " + hit.transform.name );
48.             return false;
49.         }
50.         else
51.             return true;
52.     }
53.  
54.     void Start()
55.     {
56.         position = transform.position;
57.         rotation = transform.rotation;
58.     }
59.  
60.     void Update()
61.     {
62.    
63.         transform.rotation = Quaternion.RotateTowards( transform.rotation, rotation, Time.deltaTime * rotationSpeed );
64.         transform.position = Vector3.MoveTowards( transform.position, position, Time.deltaTime * moveSpeed );
65.     }
66.  
67.     private bool isAnimating()
68.     {
69.         if ( transform.position != position )
70.             return true;
71.         if ( ( rotation.eulerAngles - transform.rotation.eulerAngles ).sqrMagnitude > 0.1f )
72.             return true;
73.         else
74.             transform.rotation = rotation;
75.         return false;
76.     }
77. }
78.  

 

I'm getting closer, but the worldDirection stuff is still hanging me up. I'm getting wonky rotation effects when I turn it on (I now rotate in place properly if I have it off, but my movement direction is locked) and my controls lock up.

Current code looks like....

Code (JavaScript):

1. #pragma strict
2.  
3. private var speed = 10.0;
4. private var pos : Vector3;
5. private var tr : Transform;
6. private var rot : Quaternion;
7. private var tiltAngle = 90.0;
8. private var rotSpeed = 140.0;
9. public var worldDirection : Vector3;
10.  
11. function Start () {
12.     pos = transform.position;
13.     tr = transform;
14.     rot = transform.rotation;
15. }
16.  
17. function Update () {
18.    
19.     if (Input.GetKeyDown(KeyCode.E) && tr.position == pos) {
20.         pos += Vector3(5,0,0); //right
21.     }
22.     else if (Input.GetKeyDown(KeyCode.Q) && tr.position == pos) {
23.         pos += Vector3(-5,0,0); //left
24.     }
25.     else if (Input.GetKeyDown(KeyCode.W) && tr.position == pos) {
26.         pos += Vector3(0,0,5); //forward  
27.     }
28.     else if (Input.GetKeyDown(KeyCode.S) && tr.position == pos) {
29.         pos += Vector3(0,0,-5); //backward
30.     }
31.     else if (Input.GetKeyDown(KeyCode.D) && tr.position == pos) {
32.         //z += Input.GetAxis("Horizontal") * rotSpeed * Time.deltaTime;  
33.         rot = rot * Quaternion.Euler (0,90,0);
34.     }
35.     else if (Input.GetKeyDown(KeyCode.A) && tr.position == pos) {
36.         //z -= Input.GetAxis("Horizontal") * rotSpeed * Time.deltaTime;  
37.         rot = rot * Quaternion.Euler (0,-90,0);
38.     }
39.  
40.     transform.rotation = Quaternion.RotateTowards (transform.rotation, rot, Time.deltaTime * rotSpeed);
41.     worldDirection = transform.TransformDirection(pos);
42.     transform.position = Vector3.MoveTowards(transform.position, worldDirection, Time.deltaTime * speed);
43. }

I feel like this is getting close to working, I'm just missing something.

 

Change the last line to

Code (CSharp):

1.     transform.position = Vector3.MoveTowards(transform.position, worldDirection + tr.position, Time.deltaTime * speed);
2.  

And in update

Code (CSharp):

1.   If(!isAnimating)
2. {
3. if (Input.GetKeyDown(KeyCode.E) ) {
4.         pos += Vector3(5,0,0); //right
5.     }
6.     else if (Input.GetKeyDown(KeyCode.Q) ) {
7.         pos += Vector3(-5,0,0); //left
8.     }
9.     else if (Input.GetKeyDown(KeyCode.W) ) {
10.         pos += Vector3(0,0,5); //forward
11.     }
12.     else if (Input.GetKeyDown(KeyCode.S)) {
13.         pos += Vector3(0,0,-5); //backward
14.     }
15.     else if (Input.GetKeyDown(KeyCode.D)) {
16.         //z += Input.GetAxis("Horizontal") * rotSpeed * Time.deltaTime;
17.         rot = rot * Quaternion.Euler (0,90,0);
18.     }
19.     else if (Input.GetKeyDown(KeyCode.A) ) {
20.         //z -= Input.GetAxis("Horizontal") * rotSpeed * Time.deltaTime;
21.         rot = rot * Quaternion.Euler (0,-90,0);
22.     }
23. }

Otherwise you will be able to move while rotating and you'll be soon off the grid.

 

Still doesn't work. Leaving my last execution lines as...

Code (JavaScript):

1.  
2. transform.rotation = Quaternion.RotateTowards (transform.rotation, rot, Time.deltaTime * rotSpeed);
3.     worldDirection = transform.TransformDirection(pos);
4.     transform.position = Vector3.MoveTowards(transform.position, worldDirection + tr.position, Time.deltaTime * speed);

just causes my player object to just fly off forever when I run the game with no keyboard response.

 

I think it because 'pos' dont get updated at all now.
change:

Code (CSharp):

1.  
2. worldDirection = transform.TransformDirection(pos);
3. transform.position = Vector3.MoveTowards(transform.position, worldDirection + tr.position, Time.deltaTime * speed);
4.  

to:

Code (CSharp):

1.  
2. [U]pos[/U] = transform.TransformDirection(pos);+ tr.[URL='http://unity3d.com/support/documentation/ScriptReference/30_search.html?q=position'][U]position[/U][/URL];
3. transform.position = Vector3.MoveTowards(transform.position, [U][COLOR=#0066cc]pos[/COLOR][/U], Time.deltaTime * speed);
4.  

My code is working, so yours cant be far away either.

 

Could you post your complete code? Even with that change I'm still flying off forever with no input. I think worldDirection/pos is getting updated continually with new values, which is why I'm flying off. I don't know why.

 

I'm giving you a treat with two files. These are certified to work.

Spoiler: PlayerMovement

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public enum MoveDirections
5. {
6.     None,
7.     Forward,
8.     Right,
9.     Back,
10.     Left
11. }
12.  
13. public class PlayerMovement : MonoBehaviour {
14.  
15.     public float gridSize = 5f;
16.  
17.     public float animationSpeed = 15f;
18.  
19.     public Vector3 position;
20.     public Quaternion rotation;
21.  
22.     public void Move( MoveDirections dir )
23.     {
24.         if ( isAnimating() )
25.             return;
26.  
27.         Vector3 moveDirection = Vector3.zero;
28.  
29.         switch ( dir )
30.         {
31.             case MoveDirections.Forward:
32.                 {
33.                     moveDirection = Vector3.forward;
34.                     break;
35.                 }
36.             case MoveDirections.Right:
37.                 {
38.                     moveDirection = -Vector3.left;
39.                     break;
40.                 }
41.             case MoveDirections.Back:
42.                 {
43.                     moveDirection = -Vector3.forward;
44.                     break;
45.                 }
46.             case MoveDirections.Left:
47.                 {
48.                     moveDirection = Vector3.left;
49.                     break;
50.                 }
51.             default:
52.                 {
53.                     Debug.LogWarning( "Unknown direction" );
54.                     break;
55.                 }
56.         }
57.         Move( moveDirection );
58.     }
59.  
60.     private bool isAnimating()
61.     {
62.         if ( transform.position != position )
63.             return true;
64.         if ( ( rotation.eulerAngles - transform.rotation.eulerAngles ).sqrMagnitude > 0.1f )
65.             return true;
66.         else
67.             transform.rotation = rotation;
68.         return false;
69.     }
70.  
71.     public void Turn( bool left )
72.     {
73.         if ( isAnimating() )
74.             return;
75.         if ( !left )
76.             rotation = rotation * Quaternion.Euler( 0, 90, 0 );
77.         else
78.             rotation = rotation * Quaternion.Euler( 0, -90, 0 );
79.     }
80.  
81.     private void Move( Vector3 dir )
82.     {
83.         //Translates direction from local to world
84.         Vector3 worldDirection = transform.TransformDirection( dir );
85.  
86.        
87.         if ( isFreeTile( worldDirection ) )
88.         {
89.             position = worldDirection * gridSize + transform.position;
90.         }
91.     }
92.  
93.  
94.     private bool isFreeTile( Vector3 worldDirection )
95.     {
96.  
97.         RaycastHit hit;
98.  
99.         //Debug.DrawLine( transform.position, transform.position + worldDirection * gridSize, Color.red, 1f );
100.  
101.         if ( Physics.Raycast( transform.position, worldDirection, out hit, gridSize ) )
102.         {
103.             Debug.Log( "Bump " + hit.transform.name );
104.             return false;
105.         }
106.         else
107.             return true;
108.     }
109.  
110.  
111.     // Use this for initialization
112.     void Start () {
113.         position = transform.position;
114.         rotation = transform.rotation;
115.     }
116.  
117.     // Update is called once per frame
118.     void Update()
119.     {
120.         transform.rotation = Quaternion.RotateTowards( transform.rotation, rotation, Time.deltaTime * 300f );
121.         transform.position = Vector3.MoveTowards( transform.position, position, Time.deltaTime * animationSpeed );
122.     }
123. }
124.  

Spoiler: PlayerInputMod.cs

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class PlayerInputMod : MonoBehaviour
5. {
6.  
7.     PlayerMovement playerMovement;
8.  
9.     // Use this for initialization
10.     void Start()
11.     {
12.         playerMovement = GetComponent<PlayerMovement>();
13.     }
14.  
15.     // Update is called once per frame
16.     void Update()
17.     {
18.  
19.         if ( Input.GetKeyDown( KeyCode.W ) )
20.             playerMovement.Move( MoveDirections.Forward );
21.         if ( Input.GetKeyDown( KeyCode.S ) )
22.             playerMovement.Move( MoveDirections.Back );
23.         if ( Input.GetKeyDown( KeyCode.A ) )
24.             playerMovement.Move( MoveDirections.Left );
25.         if ( Input.GetKeyDown( KeyCode.D ) )
26.             playerMovement.Move( MoveDirections.Right );
27.  
28.         if ( Input.GetKeyDown( KeyCode.Q ) )
29.             playerMovement.Turn( true );
30.         if ( Input.GetKeyDown( KeyCode.E ) )
31.             playerMovement.Turn( false );
32.     }
33.  
34.     public void MoveForward()
35.     {
36.         playerMovement.Move( MoveDirections.Forward );
37.     }
38.     public void MoveBack()
39.     {
40.         playerMovement.Move( MoveDirections.Back );
41.     }
42.     public void MoveLeft()
43.     {
44.         playerMovement.Move( MoveDirections.Left );
45.     }
46.     public void MoveRight()
47.     {
48.         playerMovement.Move( MoveDirections.Right );
49.     }
50.     public void TurnRight()
51.     {
52.         playerMovement.Turn( false );
53.     }
54.     public void TurnLeft()
55.     {
56.         playerMovement.Turn( true );
57.     }
58. }
59.  

 

Well, that certainly works exactly how I want it too. I really appreciate the work you've done to help me out. Now I need to go over it with a fine tooth comb to figure out what its doing different. Also figure out C# vs Javascript.

Again, thanks a lot.

 

No problemo. I needed the practice myself and I really was just doing that for my own project. I suggest go ahead and learn/switch to c# while your at it.