Rotate an object around a point in unity

Question

I'm new to Unity. So just for an experiment, I want to create a canon by attaching a rectangle to a circle and when the up arrow key is pressed, the canon change firing angle. So I have a rectangle object that is a sub object of a circle. And then I created a script in C# for the circle object.

Here is the codes that I have:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerController : MonoBehaviour
{
    private float rotation = 0f;
    private float timeValue = 0.0f;
    public GameObject wheele;
    private float xMin = -1.0f, xMax = 1.0f;
    // Start is called before the first frame update
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.UpArrow))
        {
            if (rotation >= -90)
                transform.Rotate(new Vector3(0.0f, 0.0f, rotation));

            rotation -= 2;
            Mathf.Clamp(rotation, -90.0f, 0);
        }
        if(Input.GetKeyDown(KeyCode.DownArrow))
        {
            if (rotation >= -90)
                transform.RotateAround(wheele.transform.position, Vector3.up,20);

            rotation += 2;
            Mathf.Clamp(rotation, -90.0f, 0);
        }


    }
}

I tried both transform. Rotate method, but it rotate around the center of the rectangle. But we need the rectangle to rotate with the axis, the center of the circle.

a ron a ron · Accepted Answer · 2019-07-09T00:17:41

You're asking how to get the pivot point changed, right? Make an empty game object and drag the cannon under it to make it a child, then drag the cannon to a point which you think is fine and rotate the empty game object instead of the cannon, which pretty much just changes the pivot point

Rotate an object around a point in unity

2 Answers