I have attached some screenshots so you can see how I have achieved this:

this is the character I am working with>>>screenshot_2

this is my animator>>>>>screenshot_1

this is my blend tree in the idle state>>>>>screenshot_3

and so far,this is my script:

using UnityEngine;

using System.Collections;

public class PlayerDirectionAndShooting : MonoBehaviour {

Rigidbody2D rbody;

Animator anim;

// Use this for initialization

void Start () {

rbody = GetComponent<Rigidbody2D> ();

anim = GetComponent<Animator> ();

}

// Update is called once per frame

void Update () {

Vector2 direction_vector = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));

anim.SetFloat("input_x", direction_vector.x);

anim.SetFloat("input_y", direction_vector.y);

if (Input.GetKeyDown("space"))

{

if (anim.GetFloat("input_x") <= -1)

{

anim.SetBool("is_shooting_left", true);

}

}

else

{

anim.SetBool("is_shooting_left", false);

};

if (Input.GetKeyDown("space"))

{

if (anim.GetFloat("input_y") <= -1)

{

anim.SetBool("is_shooting_down", true);

}

}

else

{

anim.SetBool("is_shooting_down", false);

};

if (Input.GetKeyDown("space"))

{

if (anim.GetFloat("input_y") <= 1)

{

anim.SetBool("is_shooting_up", true);

}

}

else

{

anim.SetBool("is_shooting_up", false);

};

if (Input.GetKeyDown("space"))

{

if (anim.GetFloat("input_x") <= 1)

{

anim.SetBool("is_shooting_right", true);

}

}

else

{

anim.SetBool("is_shooting_right",false);

};

}

}

I'd say take a look at this line:

Vector2 direction_vector = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));

you are always creating a new vector there which is fine but what does Input.getAxisRaw() return when there was no input. what's the default?

Your problem seems to be that it always uses some default if you don't have any input. You should take a look at these defaults and think of a way of ignoring them when there wasn't.

Pseudo code should be smthn like this:

if(input) update_values();

else take_previous_values()

As the other above had mentioned. You keep destroying what data you previously had, when you should be caching it. So every time that object's update is overwith, your old data keeps falling out of scope, and needs to be made with a new one.

What you should do instead is create a private property that stores your Vector2f's data.

Another thing to be mindful of, is if-block scoping. It's not a problem right now, but I have a feeling this may crop up. Animator is very stateful. Unless it's data is declared on a superior scope, anything that is created in that if check will also be deleted once the if block is over with.