Mathf.Infinity

Description

A representation of positive infinity (Read Only).

	// Casts a ray from (0,0,0) towards (0,0,1) to the infinity and prints a message
	// if any object has touched the ray.
	// To test it, just place any object and intersect it with the white drawn line
 
	function Update () {
		// shows the line that follows the ray.
		Debug.DrawLine(Vector3.zero, Vector3.forward * 100);
		if (Physics.Raycast (Vector3.zero, Vector3.forward, Mathf.Infinity)) {
			print ("There is something in front of the object!");
		}
	}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Update() {
        Debug.DrawLine(Vector3.zero, Vector3.forward * 100);
        if (Physics.Raycast(Vector3.zero, Vector3.forward, Mathf.Infinity))
            print("There is something in front of the object!");
        
    }
}