How to manage "jump" in my 2d platform game?

Question

I'm developing a simple 2d platform game with Unity 2d. I have a problem managining my "Jump" action for the player.

I would like the player to Jump only when he has his feet on a "surface": terrain, platform, crate etc. I'm considering using colliders: when my player collides with a surface, set my bool canJump = true. When he jumps, I set canJump = false (he is midair).

My terrain has a Rigidbody2d is Kinematic and a Box Collider 2d. My Player has a Rigidbody2d is Dynamic and a Capsule Collider 2d (or a Polygon Collider.. )

The events OnCollisionEnter2d() and OnTriggerEnter2d() are never raised when Player collides with terrain.

Does anyone know what's wrong?

Thanks

EDIT: Now i'm using this to check if "something" is under my feet:

RaycastHit2D hit = Physics2D.Raycast(rb.transform.position, -Vector2.up, 0.1f);
        if (hit)
            canJump = true; 

It doesn't works! hit is always true! I'm getting mad!

Answer 1

Your way should work, however I believe that the raycast is colliding with itself. You could start the raycast below the player.

However, a better way would probably be to use the colliders combined with the state machine.

When the player comes in contact with the ground (onCollisionEnter..), set a bool/animation state(standing or something) to mark that they are on the ground. When they jump, you can set the animation to a jumping animation and set your upward force.

Then, disallow further jumping (or add a counter for things like double jumping) if the flag/state from above is not set.

You can reset the flag/animation when you collide with the ground again.