2D rotation and moving forward

Questions & Answers
1

Hello everyone,
i asked this question before and the solution did work pretty good back then, but am opening this subject now because before i was trying to solve a 2d problem in a 3d engine, but now and after the huge 2d update, i want to ask this question again,
is it possible to do something like this in unity ?

-Angle = the object angle
-Rad   = convert the object angle to randians
-Move forward :
  object.x += Math.Cos(Rad)
  object.y += Math.Sin(Rad)

i agree that i have some problems when it comes to rotation, so if any of you have a simpler way to do such a thing, maybe with RigidBody2D then i’ll be very grateful
(am looking for a 2D top down car movement like this one here )

3

SOLVED :smiley: !!!
everything worked as i mentioned above, the only thing that i ignored before is the “magnitude” variable, it seems that the whole problem was based on that, because previously i never was able to have the entire angle of an object, it was always a Vector3 that have 3 different values, i thought about return the length of that vecotr, and that’s it!! it worked :slight_smile: !!
however, one thing that i still need to do here is to make sure that the “head” of my object it’s right side, like this picture :
alt text

and here is a simple class to have a simple car movement just like in the link below, i hope it helps :

using UnityEngine;
using System.Collections;

public class FollowPath : MonoBehaviour
{

		
		public float speed ;
		public float rotationSpeed;
		//transform
		Transform myTrans;
		//object position
		Vector3 myPos;
		//object rotation
		Vector3 myRot;
		//object rotation 
		float angle;

		// Use this for initialization
		void Start ()
		{
				myTrans = transform;
				myPos = myTrans.position;
				myRot = myTrans.rotation.eulerAngles;
		}
	
		// Update is called once per frame
		void FixedUpdate ()
		{
				
				//converting the object euler angle's magnitude from to Radians	
				angle = myTrans.eulerAngles.magnitude * Mathf.Deg2Rad;


				//rotate object Right & Left
				if (Input.GetKey (KeyCode.RightArrow)) {
						myRot.z -= rotationSpeed;
				}
				if (Input.GetKey (KeyCode.LeftArrow)) {
						myRot.z += rotationSpeed;
				}


				//move object Forward & Backward
				if (Input.GetKey (KeyCode.UpArrow)) {
					
						myPos.x += (Mathf.Cos (angle) * speed) * Time.deltaTime;
						myPos.y += (Mathf.Sin (angle) * speed) * Time.deltaTime;
				}
				if (Input.GetKey (KeyCode.DownArrow)) {
						myPos.x += Mathf.Cos (angle) * Time.deltaTime;
						myPos.y += Mathf.Sin (angle) * Time.deltaTime;	
				}


				//Apply
				myTrans.position = myPos;
				myTrans.rotation = Quaternion.Euler (myRot);
				
		}
}
2

Use Transform.Rotate and Transform.Translate. You don’t need to manually mess with sines and cosines.