Creating a 2D Platformer Controller

Hi, welcome to this series on creating a 2D platformer controller that can reliably handle slopes and moving platforms. Hope you enjoy!

Full playlist: https://www.youtube.com/playlist?list=PLFt_AvWsXl0f0hqURlhyIoAabKPgRsqjz
Download source: https://github.com/SebLague/2DPlatformer-Tutorial

Episode one:

 

I've uploaded episode 02

 

And episode 03

 

And episode 04

 

Thanks a lot for the tutorial, kinda hard to understand the code at first, but after a couple times watching, I'm getting the grip....This is a really nice technique, and the movement it is really precise..

 

Hi Romi, thanks for the feedback! Let me know if you have any questions, I'd be happy to answer them.

In other news, episode 05 is out:

 

Episode 06 covers the main part of the moving platform implementation:

 

It looks great, I'll check it out. Although I did kind of hope it would cover realistic rotation of the character on slopes in line with the angle as well. Very posh accent btw...

 

Thanks Hasen, I'll add that to the list of things I might cover

Episode 07 allows passengers of a moving platform to collide with other objects:

 

Episode 08 is now up. It covers a waypoint system for controlling the movement of platforms.

 

Hey Seb,

Thanks for the excellent tutorial series. Not only is it a really cool looking controller but it also teaches you some cool ways to structure your code.

I think that One Way Platforms are a must in any 2D platformer and you should cover it. It would also be awesome if you covered one way slopes that could be used like stairs to get on the One Way Platforms. And of course you should be able to drop down from the platforms as well.

Something like this:


Which is something I really badly need!

Cheers!

 

Thanks for the great ideas Shadeless, I'll integrate those as soon as possible

 

Here is the latest episode on wall jumping:

 

Episode 10 covers variable jump height and jumping/falling through platforms.

 

Hi again, here's episode 11 on camera following:

 

Thanks for the tutorial, I've definitely learned some new tricks and the controller works fairly well. Few comments from a newer/learning programmer:

- The first few tutorials had a lot more "teaching" then the later ones. I find by the slopes I was just struggling to keep up with your typing speed with little context into what we were actually doing until I paused the video and spent time reading the code line by line, some of which I'm still not 100% clear on.

- The math explanations were great. I'd have a hard time knowing to use them with a blank sheet and an idea, but I definitely understanding how they work in this context.

Few ideas:
- One way platforms
- Rotating the character on a slope
- Ladders/ropes
- Setting up sprite (looking correct direction, etc)
- Hit reaction (pushed backwards/up when hit by something, etc)

Thanks again!

 

Thank you Senladar, for your feedback and your suggestions. I'll strive to bring more actual teaching back into future episodes. Sorry if it got a bit lost along the way ^^

 

I did a lot of platformer tutorials before and I've been wanting to come back to Unity. This seems to be a good restart! I'll try this one! Thanks!

 

Nice one

 

Hi,
Have you implemented the leaser beam type effect as you showed in first tutorial of your pervious thread.Please share that like effect.
Thanks !

"

"

 

I'm stuck on episode 2 because the player colour won't change and goes through the object the rays also aren't showing under the block even though it was working fine when I started Here's the picture and code bellow:

Spoiler: Player Code

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. [RequireComponent(typeof(Controller2D))]
5.  
6. public class Player : MonoBehaviour
7. {
8.  
9.     float moveSpeed = 6;
10.     float gravity = -20;
11.     Vector3 velocity;
12.  
13.     Controller2D controller;
14.  
15.     void Start()
16.     {
17.         controller = GetComponent<Controller2D>();
18.     }
19.  
20.     void Update()
21.     {
22.  
23.         Vector2 input = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
24.  
25.  
26.         velocity.x = input.x * moveSpeed;
27.         velocity.y += gravity * Time.deltaTime;
28.         controller.Move(velocity * Time.deltaTime);
29.     }
30. }

Spoiler: Controller2D Code

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. [RequireComponent(typeof(BoxCollider2D))]
5. public class Controller2D : MonoBehaviour
6. {
7.  
8.     public LayerMask collisionMask;
9.  
10.     const float skinwidth = .015f;
11.     public int horizontalRayCount = 4;
12.     public int verticalRayCount = 4;
13.  
14.     float horizontalRaySpacing;
15.     float verticalRaySpacing;
16.  
17.  
18.     BoxCollider2D coll;
19.     RaycastOrigins raycastOrigins;
20.  
21.     void Start()
22.     {
23.         coll = GetComponent<BoxCollider2D>();
24.         calculateRaySpacing();
25.     }
26.  
27.     public void Move(Vector3 velocity)
28.     {
29.         UpdateRaycastOrigins();
30.         if (velocity.x != 0)
31.         {
32.             HorizontalCollisions(ref velocity);
33.         }
34.         if (velocity.y != 0)
35.         {
36.             VerticalCollisions(ref velocity);
37.         }
38.         transform.Translate(velocity);
39.     }
40.  
41.     void HorizontalCollisions(ref Vector3 velocity)
42.     {
43.         float directionX = Mathf.Sign(velocity.x);
44.         float rayLength = Mathf.Abs(velocity.x) + skinwidth;
45.  
46.         for (int i = 0; i < horizontalRayCount; i++)
47.         {
48.             Vector2 rayOrigin = (directionX == -1) ? raycastOrigins.bottomLeft : raycastOrigins.bottomRight;
49.             rayOrigin += Vector2.up * (horizontalRaySpacing * i);
50.             RaycastHit2D hit = Physics2D.Raycast(rayOrigin, Vector2.right * directionX, rayLength, collisionMask);
51.  
52.             Debug.DrawRay(rayOrigin, Vector2.right * directionX * rayLength, Color.red);
53.  
54.             if (hit)
55.             {
56.                 velocity.x = (hit.distance - skinwidth) * directionX;
57.                 rayLength = hit.distance;
58.             }
59.         }
60.     }
61.  
62.     void VerticalCollisions(ref Vector3 velocity)
63.     {
64.         float directionY = Mathf.Sign(velocity.y);
65.         float rayLength = Mathf.Abs(velocity.y) + skinwidth;
66.  
67.         for (int i = 0; i < verticalRayCount; i++)
68.         {
69.             Vector2 rayOrigin = (directionY == -1) ? raycastOrigins.bottomLeft : raycastOrigins.topLeft;
70.             rayOrigin += Vector2.right * (verticalRaySpacing * i + velocity.x);
71.             RaycastHit2D hit = Physics2D.Raycast(rayOrigin, Vector2.up * directionY, rayLength, collisionMask);
72.             Debug.DrawRay(rayOrigin, Vector2.up * directionY * rayLength, Color.red);
73.  
74.             if (hit)
75.             {
76.                 velocity.y = (hit.distance - skinwidth) * directionY;
77.                 rayLength = hit.distance;
78.             }
79.         }
80.     }
81.  
82.     void UpdateRaycastOrigins()
83.     {
84.         Bounds bounds = coll.bounds;
85.         bounds.Expand(skinwidth * -2);
86.  
87.         raycastOrigins.bottomLeft = new Vector2(bounds.min.x, bounds.min.y);
88.         raycastOrigins.bottomRight = new Vector2(bounds.max.x, bounds.min.y);
89.         raycastOrigins.topLeft = new Vector2(bounds.min.x, bounds.max.y);
90.         raycastOrigins.topRight = new Vector2(bounds.max.x, bounds.max.y);
91.  
92.     }
93.     void calculateRaySpacing()
94.     {
95.         Bounds bounds = coll.bounds;
96.         bounds.Expand(skinwidth * -2);
97.  
98.         horizontalRayCount = Mathf.Clamp(horizontalRayCount, 2, int.MaxValue);
99.         verticalRayCount = Mathf.Clamp(verticalRayCount, 2, int.MaxValue);
100.  
101.         horizontalRaySpacing = bounds.size.y / (horizontalRayCount - 1);
102.         verticalRaySpacing = bounds.size.x / (verticalRayCount - 1);
103.     }
104.  
105.  
106.     struct RaycastOrigins
107.     {
108.         public Vector2 topLeft, topRight;
109.         public Vector2 bottomLeft, bottomRight;
110.     }
111.  
112. }
113.  

Pls Help

 

This is a great tutorial, thanks for posting it.

 

Hi Sebastian,
your tutorials are excellent. Thank you so much. While following the first part of the tutorial I got a compiler warning which I don't understand.

In the Controller2d script, we create a reference to the BoxCollider2d with the name "collider". When compiling, I get the message: "Controller2d.collider hides inherited member 'UnityEngine.Component.collider'.Use the new keyword if hiding was intended*

Ok so the Component class defines a member called "collider" I thought. but the script reference of the Component class does not mention the member variable. Also creating an empty script extending MonoBehavior does not bring up the variable "collider" in the code-completion.

While I could easily make the warning go away by naming the reference boxCollider or so, I would like to understand this warning. Did you also get the warning?

Thanks for any hint on the topic.

kind regards
Fred

 

Found this:
Removed in version 5.3.2p2
Property collider has been deprecated. Use GetComponent<Collider>() instead. (UnityUpgradable)

There used to be a reference which was filled if a Collider was attached to the GameObject and null if not.

 

Hi everyone, this series has been dormant for about a year, but I've recently decided to take it further.
Here is the latest episode:

 

Episode 13 is now out. It covers auto sliding down steep slopes.

 

@SebastianLague Hi Seb - Awesome tutorials btw. Were you ever able to make a tut for Castlevania-style stairs? Or know of any good resources online?

 

Is this the end of this series or you are adding anything else? @SebastianLague

 

Totally late to the game question!

When putting two moving platforms next to each other, the player moves to the one of them:


https://imgur.com/LLOtEol

Any ideas on how to make that not happen?

Thanks!

 

Hmm...looks like it's being pulled both ways: