Collision on X axis means 0 movement in Y axis

问题

I'm developing a platformer in Unity using the 2D engine. I have my player character which has a BoxCollider2D and a RigidBody, and a number of 'walls' which have BoxColliders.

Now, I copied the script for moving the player from another project and made some changes. The part which has to do with movement is as follows:

public void FixedUpdate()
    {
        physVel = Vector2.zero;

        // move left
        if(Input.GetKey(KeyCode.LeftArrow))
        {
            physVel.x = -runVel;
        }

        // move right
        if(Input.GetKey(KeyCode.RightArrow))
        {
            physVel.x = runVel;
        }

        // jump
        if(Input.GetKey(KeyCode.UpArrow))
        {
            if(jumps < maxJumps)
            {
                jumps += 1;
                if(jumps == 1)
                {
                    _rigidbody.velocity = new Vector2(physVel.x, jumpVel);
                }
            }
        }

        //Apply gravity

        _rigidbody.AddForce(-Vector3.up * fallVel);


        // actually move the player
        _rigidbody.velocity = new Vector2(physVel.x, _rigidbody.velocity.y);
    }

Now this works perfectly fine.

The problem arises if the player jumps into a wall. If I keep the direction button mashed 'towards' the wall after having jumped, he is suspended in mid-air. As in the collision appears to be reducing movement on both axis to zero. If I release the direction, he falls normally. Collisions on the other axis works fine. I can hit my head or walk without issue.

Am I missing something obvious?

回答1:

EDIT: try adding a material with 0 friction to both player and walls and see what happens, if it stops it is a friction error.

来源：https://stackoverflow.com/questions/25042690/collision-on-x-axis-means-0-movement-in-y-axis