C# CarDamage script: Array index is out of range error.

[Reefer]

So the problem is that I have an car damage script, which deforms mesh on collision. It works but it keeps giving me this error and I don’t understand what’s wrong it. So if someone could point me on right direction.

ERROR:

IndexOutOfRangeException: Array index is out of range.
CarDamage2.OnCollisionEnter (UnityEngine.Collision collision) (at Assets/Scripts/CarDamage2.cs:44)

SCRIPT:

using UnityEngine;
using System.Collections;

public class CarDamage2 : MonoBehaviour 
{
	public float maxMoveDelta = 1.0f; // maximum distance one vertice moves per explosion (in meters)
	public float maxCollisionStrength = 50.0f;
	public float YforceDamp = 0.1f; // 0.0 - 1.0
	public float demolutionRange = 0.5f;
	public float impactDirManipulator = 0.0f;
	public MeshFilter[] optionalMeshList;
	
	private MeshFilter[] meshfilters;
	private float sqrDemRange;

	public void Start()
	{
        //maxMoveDelta = Mathf.Clamp01(maxMoveDelta);
       
        
        if(optionalMeshList.Length>0)
        	meshfilters = optionalMeshList;
        else
        	meshfilters = GetComponentsInChildren<MeshFilter>();
        	
        sqrDemRange = demolutionRange*demolutionRange;
        	
        /* doesnt work, strange physic behaviour
        for(int j=0; j<meshfilters.Length; ++j)
        {
       		if(!meshfilters[j].transform.collider)
       	 	{
        		meshfilters[j].gameObject.AddComponent<BoxCollider>();		
        		meshfilters[j].transform.collider.isTrigger = true;	
        	}
        }*/
	}
	
	public void OnCollisionEnter( Collision collision ) 
	{
		Vector3 colRelVel = collision.relativeVelocity;
		colRelVel.y *= YforceDamp;
		
		Vector3 colPointToMe = transform.position - collision.contacts[0].point;

		// Dot = angle to collision point, frontal = highest damage, strip = lowest damage
		float colStrength = colRelVel.magnitude * Vector3.Dot(collision.contacts[0].normal, colPointToMe.normalized);

		OnMeshForce( collision.contacts[0].point, Mathf.Clamp01(colStrength/maxCollisionStrength) );
		Debug.DrawLine(collision.contacts[0].point, transform.position, Color.red);
		//Debug.Break();
	}
	
	// if called by SendMessage(), we only have 1 param
	public void OnMeshForce( Vector4 originPosAndForce )
	{
        OnMeshForce( (Vector3)originPosAndForce, originPosAndForce.w );
	}

	public void OnMeshForce( Vector3 originPos, float force )
	{
        // force should be between 0.0 and 1.0
        force = Mathf.Clamp01(force);
        
        for(int j=0; j<meshfilters.Length; ++j)
        {
        	Vector3 [] verts = meshfilters[j].mesh.vertices;

        	for (int i=0;i<verts.Length;++i)
        	{
        		Vector3 scaledVert = Vector3.Scale( verts*, transform.localScale );						*

_ Vector3 vertWorldPos = meshfilters[j].transform.position + (meshfilters[j].transform.rotation * scaledVert);_
Vector3 originToMeDir = vertWorldPos - originPos;
Vector3 flatVertToCenterDir = transform.position - vertWorldPos;
flatVertToCenterDir.y = 0.0f;

// 0.5 - 1 => 45° to 0° / current vertice is nearer to exploPos than center of bounds
if( originToMeDir.sqrMagnitude < sqrDemRange ) //dot > 0.8f )
{

• float dist = Mathf.Clamp01(originToMeDir.sqrMagnitude/sqrDemRange);*
  float moveDelta = force * (1.0f-dist) * maxMoveDelta;

_ Vector3 moveDir = Vector3.Slerp(originToMeDir, flatVertToCenterDir, impactDirManipulator).normalized * moveDelta;_

verts += Quaternion.Inverse(transform.rotation)*moveDir;

//Debug.DrawRay(vertWorldPos, moveDir, Color.red);
//Debug.DrawLine(vertWorldPos, transform.position, Color.green);
///Debug.Break();
}

* }*

* meshfilters[j].mesh.vertices = verts;*
* meshfilters[j].mesh.RecalculateBounds();*
}
* }*
}
ERROR LINE FROM CODE:
---------------------
Vector3 colPointToMe = transform.position - collision.contacts[0].point;

[ColdPluto]

If there is no collision, the array will be empty. 0 is always the first element in an array. If an array is empty, element 0 does not exist. Check if the array size is greater than 0 before using it.