Rigidbody2D: How do I prevent the Y axis from being overwritten with 0?-CodePudding

public void MoveCharacter(float directionHori) //either -1 or 1
{      
    direction = new Vector2 (directionHori, 0); //new vector2 using passed x value (1 or -1). //BUG - passing in 0 as Y axis overrides gravity while player is moving.

    rb.MovePosition(rb.position   direction * moveSpeed * Time.fixedDeltaTime); //apply movement 
}

Above is my MoveCharacter method, and when it is called, the Y axis is overwritten with 0 therefore gravity is disabled, allowing the player to fly when he's supposed to fall. This is a 2D sidescroller, therefore the player should not be able to move vertically (except when falling of course). I've tried direction = new Vector2 (directionHori, rb.Velocity.y); //replacing 0 with rb.Velocity

however that creates weirder behavior. Any help would be appreciated, I'm still new to Unity! Many thanks.

CodePudding user response：

Instead of using MovePosition where you would need to calculate the final position yourself you could rather simply adjust the velocity like

var velocity = rb.velocity;
velocity.x = direction * moveSpeed;
rb.velocity = velocity;

this keeps the gravity and vertical movement untouched and the Rigidbody2D / the physics engine does the calculation for you ;)

CodePudding user response：

Relating to derHugo's answer, you want to use rb.velocity (or rb.AddForce()) instead. Also, when moving a rigidbody object it is best to call your move method from FixedUpdate(), because regular Update() is called every frame; Where as FixedUpdate() is called with the physics engine (about every other frame). Since a rigidbody object is a physics object, you could experience weird behaviour when trying to move from regular Update().