黑洞物理( 2D )

Question

我试图有一个黑洞，就像物理一样，它会吸引任何物体靠近它，然后把它放到黑洞轨道上，就像一个漩涡，让它转到中心然后消失。

我最终得到了这样的东西，但不起作用

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

[DisallowMultipleComponent]
[ExecuteInEditMode]
[RequireComponent(typeof(CircleCollider2D))]
[RequireComponent(typeof(SpriteRenderer))]
public class BlackHole : MonoBehaviour
{    
    /// <summary>  </summary>
    public const float          GRAVITY_PULL    = 7000.0f;
    /// <summary>  </summary>
    private const float         SWIRLSTRENGTH   = 5f;

    // ------------------------------------------------
    /// <summary>  </summary>
    private float               _gravityRadius  = 7.0f;    
    /// <summary>  </summary>
    private List<Rigidbody2D>   _rigidBodies    = new List<Rigidbody2D>();
    // ------------------------------------------------

#if UNITY_EDITOR     
    void Update()
    {
        if( Application.isPlaying == false )
        {
            _gravityRadius = 
                GetComponent<CircleCollider2D>().radius;
        }
    }
#endif 

    private void LateUpdate()
    {    
        UpdateBlackHole();
    }


    /// <summary>
    /// Attract objects towards an area when they come within the bounds of a collider.
    /// This function is on the physics timer so it won't necessarily run every frame.
    /// </summary>
    /// <param name="in_other">Any object within reach of gravity's collider</param>
    void OnTriggerEnter2D(
        Collider2D in_other
    )
    {
        if ( in_other.attachedRigidbody != null 
            && _rigidBodies != null )
        {                
            //to get them nice and swirly, use the perpendicular to the direction to the vortex
            Vector3 direction = 
                    transform.position - in_other.attachedRigidbody.transform.position;
            var tangent = 
                    Vector3.Cross(direction, Vector3.forward).normalized * SWIRLSTRENGTH;

            in_other.attachedRigidbody.velocity = 
                                            tangent;            
            _rigidBodies.Add( in_other.attachedRigidbody );
        }
    }

    private void UpdateBlackHole()
    {
        if( _rigidBodies != null )
        {
            for (int i = 0; i < _rigidBodies.Count; i++)
            {
                if( _rigidBodies[i] != null )
                {
                    CalculateMovement( _rigidBodies[i] );
                }
            }
        }
    }

    

    private void CalculateMovement(
        Rigidbody2D in_rb
    )
    {
        float distance = 
                Vector3.Distance(
                                transform.position, 
                                in_rb.transform.position
                            ); 

        float gravityIntensity = 
                        distance
                            / _gravityRadius;

        in_rb.AddForce(
                (transform.position - in_rb.transform.position) 
                                                        * gravityIntensity 
                                                                * in_rb.mass   
                                                                        * GRAVITY_PULL 
                                                                                * Time.deltaTime);
        
        in_rb.drag += 0.0001f;
        
        Debug.DrawRay(
                in_rb.transform.position, 
                transform.position - in_rb.transform.position
                );


        if( distance <= 0.1f )
        {
            _rigidBodies.Remove( in_rb );

            Destroy( in_rb.gameObject );
        }
    }
}

这会使物体从黑洞的中心上下移动，并提高它的速度，这是我想要的，但是为了上下，我想让它绕着它运行，然后在时间里接近黑洞的中心。

有什么帮助吗？

更新1:通过在开始时增加一个小力，我能够使它在黑洞周围旋转，但它不会掉到黑洞的中心。

更新2:通过添加一些拖动来解决这个问题，如果有人试图实现同样的目标，请随意使用此脚本。

Answer 1

你需要给物体一些启动力，因为它会给出水平速度，并形成一个轨道。为了使它向内螺旋，使开始力非常小，它会以一定的水平速度向黑洞下降。