How to make Z one directional?

Questions & Answers
1

Hi i want my player to be able to move forward but make him unable to move backwards what do i need to change in this script?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Playercontroller : MonoBehaviour {

public float speed;

private Rigidbody rb;

void Start ()
{
    rb = GetComponent<Rigidbody>();
}


void FixedUpdate ()
{
    float moveHorizontal = Input.GetAxis ("Horizontal");
    float moveVertical = Input.GetAxis("Vertical");

    Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);

    rb.AddForce (movement * speed);
}

}

2

you can use an if statement:

if (this.transform.position.z <= minimumZ)
{
 this.transform.position = new vector3(this.transform.position.x, this.transform.position.y, minimumZ);
}