problem with movetowards

Hi everyone,

When I move an object with movetowards to it's destination it gives no problems but when I change the destination before it reaches it's previous destination the object doesn't move towards it's newest target location.

Code (CSharp):

1.    
2. void PosSet()
3. {
4. newPOS = wPpos;
5. }
6.  
7. void Update()
8.     {
9.         Dummy1.transform.position = Vector3.MoveTowards(new Vector3(Dummy1.transform.position.x,      Dummy1.transform.position.y,0), newPOS, 8 * Time.deltaTime);
10.     }
11.  
12.     void AwayFA()
13.     {
14.         if (transform.position.y > distChck) //when Dummy1 reaches a certain y-value (distChck) the target destination vector will be adjusted. When dc is true the Dummy1 object should fly back to it's starting point (strtPoS) but the x-value of it's destination doesn't match with the starting point. The y-value does however.
15.         {
16.             if (!dc)
17.             {
18.                 if (!PosX) //linksom
19.                 {
20.                     newPOS.x = newPOS.x - 7f;
21.                     newPOS.y = newPOS.y + 3.5f;
22.                 }
23.                 else //rechtsom
24.                 {
25.                     newPOS.x = newPOS.x + 7f;
26.                     newPOS.y = newPOS.y + 3.5f;
27.                 }
28.                 distChck = Dummy1.transform.position.y - (0.5f * 3.5f);
29.                 dc = true;
30.             }
31.             else
32.             {
33.                 newPOS = strtPoS;
34.                 Breturn = true;
35.             }
36.         }
37.     }

Does movetowards malfunction when I change the target destination while running or is there something else going on.

Thanks in advance !

 

Probably you override somewhere position with PosSet ()

On side note
newPOS.y = newPOS.y + 3.5f ;
is same what
newPOS.y += 3.5f ;

Do Debug.Log and/or breakpoints, to track problem down.

 

Thanks for your reply. I made the code very simple so I can emphasize the core of the problem.
The object will change destination before it reaches it's first destinaton (goal1) but it will never reach it's new destination (goal2).

The file is uploaded so you can see it for yourself. The problem is that the object doesn't move to it's given destination when using movetowards.

Here is the code;

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class move2 : MonoBehaviour {
6.  
7.     Vector3 newPOS;
8.  
9.     // Use this for initialization
10.     void Start ()
11.     {
12.         newPOS = GameObject.Find("goal1").transform.position;
13.     }
14.  
15.     // Update is called once per frame
16.     void Update ()
17.     {
18.         SetNewPos();
19.  
20.         this.transform.position = Vector3.MoveTowards(new Vector3(transform.position.x, transform.position.y, 0), newPOS, 8 * Time.deltaTime);
21.     }
22.  
23.     void SetNewPos()
24.     {
25.         if (transform.position.y > (newPOS.y - 2))
26.         {
27.             Debug.Log("change destination");
28.             newPOS = GameObject.Find("goal2").transform.position;
29.         }
30.     }
31. }
32.  

Here is the file;

https://ufile.io/m4ich

 

Just to double check and confirm.
Are you want to move in right axis?
In normal Unity 3D convention, forward/back axis is Z axis, while it is set to 0, in your case.
While, Y axis is up/down and X is left/right.

 

So what does it do instead? Just stop? Go to some other location? Throw an error (perhaps a null reference exception)?

Try adding another Debug.Log at line 29, to print out the value of newPOS after you think you've changed it.

Also consider making newPOS public so you can watch it in the inspector. I suspect it's not what you think it is.

 

It's top down so the z-axis is left untouched.

 

The object moves to a different vector despite NewPos and goal2 having the same vector values. If you don't trust the file I added I can make a video to show what happens and upload it to Youtube.

 

Not sure what setup you have there, but this worked for me

Code (CSharp):

1. using UnityEngine;
2. public class Move3 : MonoBehaviour {
3.     Vector3 newPOS;
4.  
5.     public Transform goal1 ;
6.  
7.     public Transform goal2 ;
8.  
9.     public bool isSet = true ;
10.     // Use this for initialization
11.     void Start ()
12.     {
13.         newPOS = goal1.position;
14.     }
15.     // Update is called once per frame
16.     void Update ()
17.     {
18.         if ( isSet )
19.         {
20.             isSet = false ;
21.  
22.             SetNewPos();
23.         }
24.                
25.         this.transform.position = Vector3.Lerp (new Vector3(transform.position.x, transform.position.y, 0), newPOS, 1 * Time.deltaTime);
26.     }
27.     void SetNewPos()
28.     {
29.         if (transform.position.y > (newPOS.y - 2))
30.         {
31.             Debug.Log("change destination");
32.             newPOS =goal2.position;
33.         }
34.     }
35. }

 

Thanks for your reply. I used your code and in my setup the object moves to goal1 without changing destination to goal2. All my objects are empty game objects.

Also when I add a child object to my empty gameobject the y-position is much higher than the goal y-position while having the same y-vector value in the inspector.

Is there anyway I can mail or share this file so you can inspect my setup ? It makes it easier for you to help me out. Thanks in advance.

 

You trigger bool flag in game object with script, to change direction. Tick the bool flag in inspector.
Objects can be empty objects that fine. Is just bit harder to visualize. Make sure they are in different positions.

 

Here is my setup:
https://ibb.co/gJ7OTU

Here's my video

Notice that my bomber object moves way beyond my goal1 and goal2 object.

I changed your bool to y-position.

Code (CSharp):

1. using UnityEngine;
2. public class Move3 : MonoBehaviour
3. {
4.     Vector3 newPOS;
5.  
6.     public Transform goal1;
7.  
8.     public Transform goal2;
9.  
10.     public bool isSet = true;
11.     // Use this for initialization
12.     void Start()
13.     {
14.         newPOS = goal1.position;
15.     }
16.     // Update is called once per frame
17.     void Update()
18.     {
19.         //if (isSet)
20.         if (transform.position.y > (goal1.position.y - 1))
21.         {
22.            // isSet = false;
23.             SetNewPos();
24.         }
25.  
26.         this.transform.position = Vector3.Lerp(new Vector3(transform.position.x, transform.position.y, 0), newPOS, 1 * Time.deltaTime);
27.     }
28.     void SetNewPos()
29.     {
30.         Debug.Log("SetNewPos");
31.         if (transform.position.y > (newPOS.y - 0.5f))
32.         {
33.             Debug.Log("change destination");
34.             newPOS = goal2.position;
35.         }
36.     }
37. }

 

Please add Debug.Logs as I suggested above. You are making some assumption that is incorrect. Debugging is the process of finding out what your incorrect assumptions are. So Debug.Log every step, and compare what you get to what you expected.

 

I added a debug.log at line 29 and the position vector of my movable object (bomber) and my destination object is the same. I didn't got any errors. Not sure though if that is what you mean by adding debug.logs. You want me to upload another video were you can see my position vectors in my debug.logs ?

If possible I'd like to sent you the file so you can see it for yourself. It makes it easier to detect were the problem is.
https://ufile.io/m4ich

 

You want to add a Debug.Log at every step, so you can see where what you think is happening differs from what is actually happening.

That means, where you switch to goal2, you should have code like:

Code (csharp):

1.  
2.   Debug.Log("changed to " + goal2 + " at " + newPOS);
3.  

and if that still doesn't lead to insight, then in your Update method (which by the way is now incorrectly using Lerp rather than MoveTowards), you should have:

Code (csharp):

1.  
2.   Debug.Log("Moving towards " + newPOS + "; now at " + transform.position);
3.  

and actually read threw the spew this produces in the console. I guarantee you that MoveTowards does what the docs claim it should do. The problem is somewhere else, e.g., your goal2 isn't what you think it is, or it isn't where you think it is, or your y-position-based logic is wrong for where your goals are, or something like that. Don't ask us to solve it for you; you are the one sitting at your computer, in front of your project, and that is where the problem lies. Just keep gathering clues and checking assumptions, and at some point you will see what assumption is false, smack yourself in the forehead, and be on your way.

 

Hey guys I fixed the problem by using an empty gameobject as target destination without any child objects attached to it. That way my object moves to it's destination. Thanks everyone for your help.

cheers

 

It doesn't matter whether or not it has children. My guess is, in switching to the empty gameobject, you inadvertently fixed whatever wasn't properly assigned before.

But anyway, I'm glad you got it working!

 

If you're going to do that, you might want to consider using the debugger instead. Just press F9 then F5 and you're away. No coding, no recompiling, no forgetting to back out coding, no thinking "oh if only I'd logged out that other parameter instead", etc.

 

Yes, if you can learn to use the debugger that's even better. But sometimes new users find that intimidating (and the how-to details depend on what platform and code editor you use), so I usually start by suggesting Debug.Logs.

But definitely learn to use the debugger at some point; nothing like stepping through your code line by line to see what's going on!

 

Same here. I rather give a rod (debugging knowledge/exerciser), rather a fish (quick temp solution). Is very important skill, resolving many issues.