Unity approach an object in spiral motion

Question

In Unity I can handle circular motion around an object with a simple

transform.RotateAround(GameObject.Find("CubeTest").transform.position, Vector3.up, 20000*Time.deltaTime);

However, I want the object traveling in circular motion to approach this object whilst in orbit. Not entirely sure how to do this without screwing up.

If I'm reading this right you could something like: Vector3 dir = GameObject.Find("CubeTest").transform.position - transform.position; transform.translate(dir.normalized * Time.deltaTime); Just make sure to add a check for when your object is within N units from `CubeTest` — Jerdak, Apr 08 '13 at 14:15
I'm actually thinking about this one right now as well.. What a coincidence, but I'm interested in this one. I'm not sure how RotateAround works, but wouldn't your solution be completed by using LookAt? — Joetjah, Apr 08 '13 at 14:20
Oh, quite possibly! Let me take a quick look at it later when I get home. — Stupid.Fat.Cat, Apr 08 '13 at 17:26
I think that you should also look into iTween to use for such object motions. — Max Yankov, Apr 11 '13 at 18:12

SlxS · Accepted Answer · 2013-04-09T14:21:51.543

3

GameObject cube = GameObject.Find("CubeTest");    
transform.LookAt(cube.transform);
transform.Translate(transform.forward * Time.deltaTime * approachSpeed);
transform.RotateAround(cube.transform.position, Vector3.up,20000*Time.deltaTime);

I think that could do as you want? It moves towards the rotation point gradually, then rotates, giving the appearance of a deteriorating orbit.

edited Apr 09 '13 at 14:21

answered Apr 09 '13 at 14:18

SlxS

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3
8

That what I was thinking as well, though I dare not to speculate about the `RotateAround`-function without me having seen it first. I'm unsure if rotating the object affects the total rotation... – Joetjah Apr 09 '13 at 14:22

score 0 · Answer 2 · answered Nov 30 '22 at 19:58

If you came here looking for working 2D solution here you are.

From this blog post. I built this configurable script:

public class SpiralMovement : MonoBehaviour
{
    [SerializeField] Transform moveable;
    [SerializeField] public Transform destiny;
    [SerializeField] float speed;
    
    // As higher as smoother approach, but it can not be more than 90, or it will start getting away.
    [SerializeField][Range(0f, 89f)] float angle = 60f;

    void Update()
    {
        Vector3 direction = destiny.position - moveable.position;
        direction = Quaternion.Euler(0, 0, angle) * direction;
        float distanceThisFrame = speed * Time.deltaTime;

        moveable.transform.Translate(direction.normalized * distanceThisFrame, Space.World);
    }
}

Unity approach an object in spiral motion

2 Answers2