2D TOP DOWN - W A S D as direction

Questions & Answers
1

Hello I need here really a help

I am making a top down 2d tank shooter game. The direction should based on keys WASD. So if I want to go right the Z rotiation should be zero. If I go to left so it should be 270. So I don’t know really how to calculate it. Because the Quaternion gives me headache.

When I used old engine it was without Quaternion. I just made Direction.ToAngle() and I got the angle were I could use .setAngle(angle). For smooth I just did SmoothAng = currentAng - (angle - CurrentAng) *0.1f (it hadn’t lerp)
In Unity it needs to Vectors to get an angle which confusing me while in old engine I used just one Vector like Quaternion.Euler.

Quaternion seems more complex. There is LookRotation or something else. Don’t know really how these do the culculation. So I hope you can help me :S

Important!! It needs to be a smooth rotation.

2

While this can easily be done with Quaternions, it also can be easily done just using eulerAngles. Given you are rotating around ‘y’ axis, you can do something like this:

#pragma strict

var speed = 3.0;
private var angleTo = 0.0;
private var angle = 0.0;
 
function Update() {
	if (Input.GetKeyDown(KeyCode.A))
		angleTo = -90.0;
	if (Input.GetKeyDown(KeyCode.S))
		angleTo = 180.0;
	if (Input.GetKeyDown(KeyCode.D)) 
		angleTo = 90.0;
	if (Input.GetKeyDown(KeyCode.W))
		angleTo = 0.0;
		
	angle = Mathf.Lerp(angle, angleTo, Time.deltaTime * speed);
	transform.eulerAngles = Vector3(0.0, angle, 0.0);
}

A couple things to note here. First, I never read from eulerAngles. I keep my own variable (angle) and just write to them. Second, I’m using Time.deltaTime instead of 0.1. Since the time of each frame varies, you cannot used a fixed value in Update(). You could use a fixed value if you wanted to use FixedUpdate().

3

Well, I think this is solution (sorry because it is in C#):

rb.MovePosition(rb.position + new Vector2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical")) * [speed of character, for example 5] * Time.fixedDeltaTime);