How to send a Ray through a vertex?

I am trying to create a custom shadow solution for casting a shadow on a flat plane in unity indie. For me to do t$$anonymous$$s I need to cast a ray through each vertex of the model that is casting the shadow. T$$anonymous$$s is what I have so far, but it does not work because the rays do not pass through the vertices.

public class Caster : MonoBehaviour {

  public GameObject meshTrans; 
     
     public Transform ground; 
     
     private float y1, y2; 
     
     Vector3[] vertices; 
     
     // Use t$$anonymous$$s for initialization
     void Start () {
         if (meshTrans != null) vertices = meshTrans.GetComponent<MeshFilter>().mesh.vertices; 
         
     }
     
     // Update is called once per frame
     void Update () {
         
         for (int i = 0; i < vertices.Length; i++) {
             y1 = transform.position.y - vertices[0].y; 
             y2 = vertices[0].y - ground.position.y; 
             Vector3 v = vertices[0] - transform.position; 
             v = v * ((y1+y2) / y1) ;
             
             Debug.DrawRay(transform.position, transform.TransformPoint(v) - transform.position, Color.red);  
         }
   
     }
 }