Camera between mouse and object. top down 2d. c#

Question

Context

I am working on a top down 2d shooter. The player moves with WASD, and always faces the mouse.

I need a camera that stays at the mid point between the player and the cursor, unless that mid point is past a certain radius away from the player. The camera cant leave that radius.

Question

I am trying to c# code a camera that does 3 things:

(I've included an image below to better explain what I mean)

Stay directly at the mid point of the player object and the mouse. figure A
The Camera can not go past a certain distance / radius away from the player. (even if mid point between player and camera exceeds that distance) figure B
Keeps track of the distance between the player object and camera object. (so I can use that variable later)

alt text

I have exhausted my google-fu, and looked through so many script examples, and I keep coming up just short.

Any help would be greatly appreciated. Thankyou.

Answer 1

Best Answer

Answer by Adam_Benko · Dec 12, 2018 at 09:06 PM

Here is a c# version of the code: All credit goes to @MD_Reptile :)

 public class CameraControll : MonoBehaviour
 {
     public Transform Parent; // Whatever you want the camera locked to
     public Transform Obj; // The object to place the camera on
     public float Radius = 4.5f;
     float Dist;
     Vector3 MousePos1, MousePos2, ScreenMouse, MouseOffset;
     public void Update()
     {
         MousePos1 = Input.mousePosition;
         // the below line assumes this script is attached to a camera object
         ScreenMouse = GetComponent<Camera>().ScreenToWorldPoint(new Vector3(MousePos1.x, MousePos1.y, Obj.position.z - GetComponent<Camera>().transform.position.z));
         MouseOffset = ScreenMouse - Parent.position;
         MousePos2 = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, -transform.position.z));
         //Obj.position.y = ((MousePos2.y - Parent.position.y) / 2.0) + Parent.position.y;
         //Obj.position.x = ((MousePos2.x - Parent.position.x) / 2.0) + Parent.position.x;
         Obj.position = new Vector3((MousePos2.x - Parent.position.x) / 2.0f + Parent.position.x, (MousePos2.y - Parent.position.y) / 2.0f + Parent.position.y, Obj.position.z);
 
         Dist = Vector2.Distance(new Vector2(Obj.position.x, Obj.position.y), new Vector2(Parent.position.x, Parent.position.y));
 
         if (Dist > Radius)
         {
             var norm = MouseOffset.normalized;
             //Obj.position.x = norm.x * Radius + Parent.position.x;
             //Obj.position.y = norm.y * Radius + Parent.position.y;
             Obj.position = new Vector3(norm.x * Radius + Parent.position.x, norm.y * Radius + Parent.position.y, Obj.position.z);
         }
     }
 }

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vProject · Dec 13, 2018 at 10:55 PM 0

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$$anonymous$$arked as answered for visibility.

Credit to @$$anonymous$$D_Reptile (who's reply I can't mark as an answer)

SpuneRune · Oct 13, 2020 at 11:36 PM 0

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It works, but its all glitchy. It shakes a little when i move the character and glitches out when i move it around

Itharen · Jan 20 at 06:44 PM 0

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This was a nice start, but I've done some improvements....:

 public class CameraControlMain2D : MonoBehaviour {
   [SerializeField] private Transform playerTransform;
 
   private float radius = 30f;
   private float smoothTime = 0.3F;
   private Vector3 velocity = Vector3.zero;
 
   public void Update() {
     Vector3 mousePosition = MousePosition.GetMouseWorldPosition(); 
 
     Vector3 newPosition = new Vector3(
       (mousePosition.x - playerTransform.position.x) / 2f + playerTransform.position.x,
       (mousePosition.y - playerTransform.position.y) / 2f + playerTransform.position.y,
       transform.position.z
     );
 
     float dist = Vector2.Distance(
       new Vector2(newPosition.x, newPosition.y), 
       new Vector2(playerTransform.position.x, playerTransform.position.y)
     );
 
     if (dist > radius) {
       Vector3 mouseOffset = mousePosition - playerTransform.position;
       var norm = mouseOffset.normalized;
       newPosition = new Vector3(
         norm.x * radius + playerTransform.position.x, 
         norm.y * radius + playerTransform.position.y, 
         transform.position.z
       );
     }
     transform.position = Vector3.SmoothDamp(transform.position, newPosition, ref velocity, smoothTime);
   }
 }
 
 public class MousePosition {
   // Get Mouse Position in World with Z = 0f
   public static Vector3 GetMouseWorldPosition() {
     Vector3 vec = GetMouseWorldPositionWithZ(Input.mousePosition, Camera.main);
     vec.z = 0f;
     return vec;
   }
 
   public static Vector3 GetMouseWorldPositionWithZ(Vector3 screenPosition, Camera worldCamera) {
     Vector3 worldPosition = worldCamera.ScreenToWorldPoint(screenPosition);
     return worldPosition;
   }
 }

Answer 2

Answer by vProject · Feb 29, 2016 at 05:22 PM

Posting this here for anyone looking for this sort of thing in the future.

This works exactly as shown in the pictures, It's JS though.

 #pragma strict
 
 var Parent : Transform; // Whatever you want to camera locked to
 var Obj : Transform; // The object to place the camera on
 var Radius = 4.5;
 var Dist : float;
 var MousePos1 : Vector3;
 var MousePos2 : Vector3;
 var ScreenMouse : Vector3;
 var MouseOffset : Vector3;
  
 function Update() {
     MousePos1 = Input.mousePosition;
     ScreenMouse = GetComponent.<Camera>().main.ScreenToWorldPoint(Vector3(MousePos1.x, MousePos1.y, Obj.position.z-GetComponent.<Camera>().main.transform.position.z));
     MouseOffset = ScreenMouse - Parent.position;
 
     MousePos2 = Camera.main.ScreenToWorldPoint(Vector3(Input.mousePosition.x, Input.mousePosition.y, -transform.position.z));
     Obj.position.y = ((MousePos2.y - Parent.position.y)/2.0)+Parent.position.y;
     Obj.position.x = ((MousePos2.x - Parent.position.x)/2.0)+Parent.position.x;
      
     Dist = Vector2.Distance(Vector2(Obj.position.x, Obj.position.y), Vector2(Parent.position.x, Parent.position.y));
      
     if(Dist > Radius){
         var norm = MouseOffset.normalized;
         Obj.position.x = norm.x*Radius + Parent.position.x;
         Obj.position.y = norm.y*Radius + Parent.position.y;
     }
 }

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RealErrorMessage · Apr 24, 2016 at 05:11 PM 0

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Is there any reason I can only find this script in JS? I'm trying to use C#, but everywhere I find something like this everyone uses JS.

MD_Reptile · Dec 10, 2018 at 10:20 PM 1

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UNTESTED C# CONVERSION:

 public class CamScript : $$anonymous$$onoBehaviour
 {
     Transform Parent; // Whatever you want to camera locked to
     Transform Obj; // The object to place the camera on
     float Radius = 4.5f;
     float Dist;
     Vector3 $$anonymous$$ousePos1, $$anonymous$$ousePos2, Screen$$anonymous$$ouse, $$anonymous$$ouseOffset;
     public void Update()
     {
         $$anonymous$$ousePos1 = Input.mousePosition;
         // the below line assumes this script is attached to a camera object
         Screen$$anonymous$$ouse = GetComponent<Camera>().ScreenToWorldPoint(new Vector3($$anonymous$$ousePos1.x, $$anonymous$$ousePos1.y, Obj.position.z - GetComponent<Camera>().transform.position.z));
         $$anonymous$$ouseOffset = Screen$$anonymous$$ouse - Parent.position;
         $$anonymous$$ousePos2 = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, -transform.position.z));
         //Obj.position.y = (($$anonymous$$ousePos2.y - Parent.position.y) / 2.0) + Parent.position.y;
         //Obj.position.x = (($$anonymous$$ousePos2.x - Parent.position.x) / 2.0) + Parent.position.x;
         Obj.position = new Vector3(($$anonymous$$ousePos2.x - Parent.position.x) / 2.0f + Parent.position.x, ($$anonymous$$ousePos2.y - Parent.position.y) / 2.0f + Parent.position.y, Obj.position.z);
  
         Dist = Vector2.Distance(new Vector2(Obj.position.x, Obj.position.y), new Vector2(Parent.position.x, Parent.position.y));
  
         if (Dist > Radius)
         {
             var norm = $$anonymous$$ouseOffset.normalized;
             //Obj.position.x = norm.x * Radius + Parent.position.x;
             //Obj.position.y = norm.y * Radius + Parent.position.y;
             Obj.position = new Vector3(norm.x * Radius + Parent.position.x, norm.y * Radius + Parent.position.y, Obj.position.z);
         }
     }
 }

Answer 3

Answer by charlessylvander · Oct 02, 2020 at 08:40 AM

@vProject check this out!

https://youtu.be/LFe017d-S58,@vProject I found a really helpful video on this. It is actually a lot simpler than you think!

https://youtu.be/LFe017d-S58

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smsyaz1 · Jul 12, 2021 at 07:34 AM 0

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thank you so much! I've searched high and low but couldn't find the answer. I know this thread is old but I just had to say thank you

Answer 4

Hi I just began to port an old unfinished project on Flash to Unity a few days ago. It's 2D topdown too. I did find a way to make a similar kind of camera script (but simpler).

My Camera and my Player aren't parent nor child from each other. Works fine for the meantime.

Here's the script in UnityScript(js): followplayer.js attached to the camera.

 #pragma strict
 
 private var player:GameObject;
 private var mousePosition:Vector2;
 private var playerPosition:Vector2;
 
 function Start () {
     player = GameObject.FindWithTag("Player");
 }
 
 function Update ():void {
     mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
     playerPosition = player.transform.position;
     
     SmoothFollow_Mouse(mousePosition, playerPosition);
 }
 
 function SmoothFollow_Mouse(a:Vector2, b:Vector2):void {
 var c:Vector2 = (a + b)/2;
 transform.position.x = (b.x + c.x)/2;
 transform.position.y = (b.y + c.y)/2;
 }

Answer 5

Answer by osybear · Dec 13, 2017 at 02:57 PM

         Ray cameraRay = Camera.main.ScreenPointToRay(Input.mousePosition);
         Plane groundPlane = new Plane(Vector3.up, Vector3.zero);
 
         float rayLength;
 
         if (groundPlane.Raycast(cameraRay, out rayLength))
         {
             Vector3 pointToLook = cameraRay.GetPoint(rayLength);
             Vector3 NewPos = (gameObject.transform.position + pointToLook) / 2;
             NewPos = new Vector3(NewPos.x, 10f, NewPos.z - 3.5f);
             playerCam.transform.position = NewPos;
         }

My camera is angled by 70* in the x and it works as expected.

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Camera between mouse and object. top down 2d. c#

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