Converts a Vector4 to a Vector2.

Vector4s can be implicitly converted to Vector2 (z and w is discarded).

	function Start () {
		// Shader vectors are always Vector4s.
		// But the value here is converted to a Vector2.
		var value : Vector2 = renderer.material.GetVector("_SomeVariable");
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Start() {
        Vector2 value = renderer.material.GetVector("_SomeVariable");
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Start() as void:
		value as Vector2 = renderer.material.GetVector('_SomeVariable')