Trying to create a random Vector3 in Unity

Question

I am trying to make a random Vector3, but Unity is giving me this error: UnityException: Range is not allowed to be called from a MonoBehaviour constructor (or instance field initializer), call it in Awake or Start instead. Called from MonoBehavior 'particleMover'. This is my code:

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

public class particleMover : MonoBehaviour
{
    public float moveSpeed;
    public float temperature;
    public Rigidbody rb;
    public Transform tf;
    static private float[] directions;

    // Start is called before the first frame
    void Start()
    {
        System.Random rnd = new System.Random();
        float[] directions = { rnd.Next(1, 360), rnd.Next(1, 360), rnd.Next(1, 360) };
    }

    // Update is called once per frame
    void Update()
    {
        Vector3 direction = new Vector3(directions[0], directions[1], directions[2]);
        direction = moveSpeed * direction;
        rb.MovePosition(rb.position + direction);
    }
}

Answer 1

Vector3 direction = Random.insideUnitSphere;

And you used (1, 360) and it seems you are confusing direction with rotation.

Vector3(x, y, z) - x, y, z are position values, not angles.

In addition, you need to use Time.deltaTime

direction = moveSpeed * direction * Time.deltaTime;

More info: https://docs.unity3d.com/ScriptReference/Time-deltaTime.html

Updated answer:

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

public class particleMover : MonoBehaviour
{
    public float moveSpeed;
    public float temperature;
    public Rigidbody rb;
    public Transform tf;
    private Vector3 direction = Vector3.zero;

    void Start()
    {
        direction = Random.insideUnitSphere;
    }

    void Update()
    {
        rf.position += direction * moveSpeed * Time.deltaTime;
        // If this script is attached to tf object
        // transform.position += direction * moveSpeed * Time.deltaTime;
    }
}