create code for draw a line in unity that shows the nearest rigidbody
Here is an example code that draws a line in Unity to show the nearest Rigidbody:
```csharp
using UnityEngine;

public class DrawNearestRigidbodyLine : MonoBehaviour
{
    public float maxDistance = 10f; // maximum distance to search for nearest Rigidbody
    public Color lineColor = Color.red; // color of the line
    public float lineWidth = 2f; // width of the line

    private LineRenderer lineRenderer; // line renderer component

    void Start()
    {
        // create a line renderer component
        lineRenderer = gameObject.AddComponent<LineRenderer>();
        lineRenderer.material = new Material(Shader.Find("Sprites/Default"));
        lineRenderer.startWidth = lineWidth;
        lineRenderer.endWidth = lineWidth;
        lineRenderer.startColor = lineColor;
        lineRenderer.endColor = lineColor;
    }

    void Update()
    {
        // find the nearest Rigidbody
        Rigidbody nearestRigidbody = FindNearestRigidbody();

        // if a Rigidbody is found, draw a line to it
        if (nearestRigidbody!= null)
        {
            DrawLineToRigidbody(nearestRigidbody);
        }
        else
        {
            // if no Rigidbody is found, reset the line renderer
            lineRenderer.positionCount = 0;
        }
    }

    Rigidbody FindNearestRigidbody()
    {
        // get all Rigidbody components in the scene
        Rigidbody[] rigidbodies = FindObjectsOfType<Rigidbody>();

        //
  To draw a line in Unity that shows the nearest rigidbody, you can use the `Raycast` function to cast a ray from the camera towards the position of the nearest rigidbody, and then check if the ray intersects with any rigidbody.

Here's an example of how you could do this:
```
using UnityEngine;

public class NearestRigidbodyLineDrawer : MonoBehaviour
{
    // The camera component
    public Camera camera;

    // The raycast tolerance
    public float raycastTolerance = 0.01f;

    void Update()
    {
        // Cast a ray from the camera towards the position of the nearest rigidbody
        Ray ray = new Ray(camera.transform.position, Camera.main.transform.forward);
        RaycastHit hit;
        if (Physics.Raycast(ray, out hit, raycastTolerance))
        {
            // Draw a line from the camera to the nearest rigidbody
            Debug.DrawLine(camera.transform.position, hit.point, Color.red);
        }
    }
}
```
In this script, we're using the `Raycast` function to cast a ray from the camera towards the position of the nearest rigidbody. The `