How can i make the circle to be drawn not from the top but from the camera view top ?

Questions & Answers
1

What i mean is that from the camera that the view is from the top i want to rotate the circle so it looks like the circle is on the ground. Not to rotate or change the camera position but to rotate the circle i think on the Z axis ?

This is how it looks like from the top view:

101545-line004.jpg
101545-line004.jpg1155×538 227 KB

And the code:

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

public class DrawCircle : MonoBehaviour
{
    public int segments;
    public float xradius;
    public float yradius;
    LineRenderer line;

    void Start()
    {
        line = gameObject.GetComponent<LineRenderer>();

        line.positionCount = segments + 1;
        line.useWorldSpace = false;
        CreatePoints();
    }

    private void Update()
    {
        if (Input.GetAxis("Mouse X") < 0)
        {
            xradius = xradius + 5;
            CreatePoints();
        }
        if (Input.GetAxis("Mouse X") > 0)
        {
            xradius = xradius - 5;
            CreatePoints();
        }
    }

    void CreatePoints()
    {
        float x;
        float y;
        float z = 0f;

        float angle = 20f;

        for (int i = 0; i < (segments + 1); i++)
        {
            x = Mathf.Sin(Mathf.Deg2Rad * angle) * xradius;
            y = Mathf.Cos(Mathf.Deg2Rad * angle) * yradius;

            line.SetPosition(i, new Vector3(x, y, z));

            angle += (360f / segments);
        }
    }
}

I want to rotate the circle so it looks like it was drawing on the terrain.
Maybe i should use somehow Ray and draw the circle already on the terrain ?

But not sure how to use it with my code:

RaycastHit hit;
            Ray ray = GetComponent<Camera>().ScreenPointToRay(Input.mousePosition);
            if (Physics.Raycast(ray, out hit, 1000))
            {
                Vector3 hitpoint = hit.point;

It’s better if i could make the circle to be drawn on the terrain it self and then using the mouse with the ray to change the xradius +5 and - 5

2

You could either rotate it by 90 deg on Z axis, or, in your circle-drawing script, you could change it so the points are on x and z axes, while the y is fixed. Something like this:

 void CreatePoints()
 {
     float x;
     float y = 0f;
     float z;

     float angle = 20f;

     for (int i = 0; i < (segments + 1); i++)
     {
         x = Mathf.Sin(Mathf.Deg2Rad * angle) * xradius;
         z = Mathf.Cos(Mathf.Deg2Rad * angle) * yradius; //this should probably be called zradius in this case

         line.SetPosition(i, new Vector3(x, y, z));

         angle += (360f / segments);
     }
 }

Note: You might need to tweak that y to something greater than zero, or if you want it to be on the ground, raycast to the ground to determine your y position.