Click to move a character

All right, I'm sure this has been done before, but my searching on the Unity forums hasn't been particularly fruitful.

I want to make a character move toward a location with a single mouse click. Pathfinding is not necessary, but it needs to be able to react properly to terrain (if the clicked point is on the other side of a hill, it would walk up the hill, and then react to gravity on the way back down). When the character reaches the destination, it stops. The character can use either a CharacterController or a Rigidbody, it doesn't really matter to me which (although there will hopefully be many characters onscreen, so if one is better on performance than the other, that would be good to know)

Has this already been built, and if so, can someone provide a link for it?

 

look at the itween examples. this exact thing is in there

 

Two basic things here.. facing your character towards a mouse position, and moving to that position

The first subject was covered by another guys thread

http://forum.unity3d.com/threads/101900-rotate-object-towards-mouse-position

The second would be covered in the CharacterController.Move documentation

http://unity3d.com/support/documentation/ScriptReference/CharacterController.Move.html

you would need to write a Coroutine, that moves the character until he is within a certain distance of the mouse position you clicked. (say 0.2 units)

The key would be to check his position in the X and Z directions, not the Y.

 

I had started with CharacterController.Move, but since that was built with keyboard input in mind, I didn't know what new value to give moveDirection in the example script.

I'll have to check out iTween.

 

Look at the Penelope tutorial. Yes, it is for mobile, BUT, it has this exact feature, only for where you touch it does a ScreenToWorld raycast, etc.

 

Well... it sort of works... but it's really choppy.

Code (csharp):

1.  
2. var speed : float = 6.0;
3. var gravity : float = 20.0;
4. private var hit: RaycastHit;
5. private var moveDirection : Vector3 = Vector3.zero;
6. private var destination : Vector3;
7.  
8. function Start() {
9.     destination = transform.position;
10. }
11.  
12. function Update() {
13.     if (Input.GetMouseButtonDown(0)){ // if the left mouse button is clicked
14.         var ray = Camera.main.ScreenPointToRay (Input.mousePosition); //cast a ray through the current mouse position from the camera
15.         if (Physics.Raycast (ray, hit, 100)  hit.collider.gameObject.tag=="Ground") { //if the ray hits the ground
16.             Debug.Log (hit.point);
17.             destination = hit.point;
18.         }
19.     }
20.    
21.     var controller : CharacterController = GetComponent(CharacterController);
22.    
23.     if (destination != transform.position) {
24.             if ((destination-transform.position).sqrMagnitude > 1.0) { //yes, this is a choppy way of getting to the endpoint... I'll fix this later
25.             var relativePos = destination - transform.position;
26.             relativePos.y = transform.position.y;
27.             var rotation = Quaternion.LookRotation(relativePos);
28.             transform.rotation = rotation;
29.  
30.             if (controller.isGrounded) {
31.                     moveDirection = Vector3.forward;
32.                     moveDirection = transform.TransformDirection(moveDirection);
33.                     moveDirection *= speed;
34.             }
35.        
36.             // Apply gravity
37.                 moveDirection.y -= gravity * Time.deltaTime;
38.            
39.                 // Move the controller
40.                 controller.Move(moveDirection * Time.deltaTime);
41.             } else {
42.                 transform.position = destination;
43.             }
44.     }
45. }
46.  

Ugh... sorry about the tabs being so huge. Copy and paste from MonoDevelop hasn't been my friend.

 

Tabs are fine.

A little more elegant soloution... (coroutine)

// make sure to debug it first.

Code (csharp):

1.  
2. var speed : float = 6.0;
3. var gravity : float = 20.0;
4. private var destination : Vector3;
5. private var iClicked=false;
6.  
7. function Start() {
8.     destination = transform.position;
9.     StartCoroutine(myCoroutine());
10. }
11.  
12. function Update() {
13.     if (Input.GetMouseButtonDown(0)){ // if the left mouse button is clicked
14.         var hit: RaycastHit;
15.         var ray = Camera.main.ScreenPointToRay (Input.mousePosition); //cast a ray through the current mouse position from the camera
16.         if (Physics.Raycast (ray, hit, 100)) { //if the ray hits the ground
17.             if(hit.collider.gameObject.tag=="Ground"){
18.                 destination = hit.point;
19.                 iClicked=true;
20.             }
21.         }
22.     }
23. }
24.  
25. function myCoroutine(){
26.     var controller : CharacterController = GetComponent(CharacterController);
27.    
28.     while(true){
29.         if(iClicked){ // if we click a mouse, look at the point we clicked
30.             transform.LookAt(destination);
31.             iClicked=false;
32.         }
33.        
34.         var moveDirection=Vector3.zero;
35.         // see if our destination is in front of us
36.         var z=transform.InverseTransformPoint(destination).z;
37.         if(z>0.2){
38.             // if it is, see if we are on the ground
39.             if (controller.isGrounded) {
40.                 // if we are, move
41.                 moveDirection = transform.forward;
42.             }
43.             // Apply gravity
44.             moveDirection.y -= gravity * Time.deltaTime;
45.             controller.Move(moveDirection * speed * Time.deltaTime);
46.         }
47.         yield;
48.     }
49. }
50.  

 

I'm pretty unfamiliar with Coroutines... how might this error be fixed? It says "No appropriate version of 'UnityEngine.MonoBehaviour.StartCoroutine' for the argument list '(void)' was found."

 

woops, forgot the yield. In Javascript a function will be defined as an IEnumerator, if you use a yield or yielding method within it's bounds. Since I forgot one, it wasn't thinking it was one.

I corrected the code above

 

Well, it fixed the bug, and I greatly appreciate the help... but I still don't know why the script is producing such a choppy result.

EDIT: Hmm... that's odd. When I put it in a new scene, it worked quite well. Perhaps something else I'd done in my old scene was causing it grief. I'll keep you posted.

 

Hi Screenhog,

Any luck identifying the cause of the choppy issue? I'm always on the look out for practices to avoid.