Issues Getting my GameObject to both Move Forward and Jump properly

Question

I'm having an issue where my gameObject barely jumps at all. I think it has something to do with moveDirection because the jumping works when I comment out p.velocity = moveDirection .

Any suggestions on how to fix this?

using UnityEngine;
using System.Collections;

public class Controller : MonoBehaviour 
{    
    public float jumpHeight = 8f;
    public Rigidbody p;    
    public float speed = 1;
    public float runSpeed = 3;
    public Vector3 moveDirection = Vector3.zero;

    // Use this for initialization
    void Start () 
    {
        p = GetComponent<Rigidbody>();
        p.velocity = Vector3.zero;
    }

    // Update is called once per frame
    void Update () 
    {
        if (Input.GetKeyDown (KeyCode.Space)) 
        {
            p.AddForce(new Vector3(0, jumpHeight, 0), ForceMode.Impulse);
        }

        Move ();   
    }

    void Move ()
    {
        if(Input.GetKey(KeyCode.D))
        {
            transform.Rotate(Vector3.up, Mathf.Clamp(180f * Time.deltaTime, 0f, 360f));
        }

        if(Input.GetKey(KeyCode.A))
        {
            transform.Rotate(Vector3.up, -Mathf.Clamp(180f * Time.deltaTime, 0f, 360f));
        }

        moveDirection = new Vector3(Input.GetAxis("Horizontal"),0,Input.GetAxis("Vertical"));
        moveDirection = transform.TransformDirection(moveDirection);

        if(Input.GetKey(KeyCode.LeftShift))
        {
            moveDirection *= runSpeed;
        }
        else
        {
            moveDirection *= speed;
        }

        p.velocity = moveDirection;
    }
}

Answer 1

Try using a much higher value for your jumpheight variable. I usually go with something in the hundreds.

Answer 2

Because right after doing the AddForce(...) literally within the same frame you override the velocity with moveDirection . You should be adding to the current velocity, instead of overriding it entirely as such:

Vector3 velocity = p.velocity;
p.velocity = velocity + moveDirection;

This is exactly why Unity warns against messing with velocity directly , youd be better off just doing another AddForce(...) for your movement:

p.AddForce(moveDirection * Time.deltaTime);

EDIT:

i don't like digressing too far from the OP's question, but your new problems are probably because you are doing too much with moveDirection half of what i don't even understand why but it should for the most part look like this:

moveDirection = new Vector3(Input.GetAxis("Horizontal"),0,Input.GetAxis("Vertical")).normalized;
float _speed = Input.GetKey(KeyCode.LeftShift) ? runspeed : speed;

p.AddForce(moveDirection * _speed * Time.deltaTime);

Answer 3

Okay I figured out how to fix it. Instead of those MoveDirection variables I changed it to

if(Input.GetKey(KeyCode.W)) {
        transform.position += transform.forward * Time.deltaTime * speed;
    }
    if(Input.GetKey(KeyCode.S)) {
        transform.position -= transform.forward * Time.deltaTime * speed;
    }

and now it works just fine.