2D Mouse Point/Click movement: character not completing movement

Unity Engine
1

Hi everyone, absolute beginner here. I’m sorry because I know it’s a stupid question for an easy script, but I can’t manage to find a solution. I want to make a 2d point and click movement script in which the player adjusts to a grid. This is the script:

public class Movement : MonoBehaviour
{
     public int speed;
     Vector3 destination;
     private void Start()
     {
         speed = 3;
     }
     private void Update()
     {
         if(Input.GetMouseButtonDown(0))
         {
             Vector3 mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
             destination = new Vector3(Mathf.RoundToInt(mousePosition.x* 2) / 2,
                     Mathf.RoundToInt(mousePosition.y * 2) / 2,
                     transform.position.z); //the math is to adjust the position to the grid
             transform.position = Vector3.MoveTowards(transform.position, destination, speed * Time.deltaTime);
         }
     }

The Player has an animator and a box collider 2d attached (I don’t think they matter); map borders have tile colliders and rigidbody (but the player doesn’t get there). When I run the game, the player only moves a tiny tiny bit and doesn’t arrive where i clicked. If I set the speed to huge numbers (ex. 100000), the player moves to the position and even dashes through colliders… What do you think?

2

Line 11 only executes on one frame. Is that your problem?

If that’s not it, then first of all I would tear this statement apart into many independent steps so you can reason about it:

If you have more than one or two dots (.) in a single statement, you’re just being mean to yourself.

How to break down hairy lines of code:

http://plbm.com/?p=248

Break it up, practice social distancing in your code, one thing per line please.

“Programming is hard enough without making it harder for ourselves.” - angrypenguin on Unity3D forums

“Combining a bunch of stuff into one line always feels satisfying, but it’s always a PITA to debug.” - Star Manta on the Unity3D forums

Once it is in a more manageable state (or not! up to you of course), here is how to set about debugging it:

You must find a way to get the information you need in order to reason about what the problem is.

What is often happening in these cases is one of the following:

  • the code you think is executing is not actually executing at all
  • the code is executing far EARLIER or LATER than you think
  • the code is executing far LESS OFTEN than you think
  • the code is executing far MORE OFTEN than you think
  • the code is executing on another GameObject than you think it is
  • you’re getting an error or warning and you haven’t noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

  • is this code even running? which parts are running? how often does it run? what order does it run in?
  • what are the values of the variables involved? Are they initialized? Are the values reasonable?
  • are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here’s an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

3

Independent of your problem, you should NEVER modify the Transform when using 2D physics. You should always modify a Rigidbody2D via its API and let it write to the Transform. A Collider2D without a Rigidbody2D means you’ve asked for a Static (non-moving) collider but instead you are modifying the Transform, causing the collider to be recreated from scratch each time you do so.

Transforms are NOT used to control the physics components, physics components are there to control the Transforms.