Unity3d Camera cage from camera to near plane in editor.

DrawCameraViewFrustrum.cs

using UnityEngine;
using System.Collections;

// Camera cage from camera to near plane in editor.
public class DrawCameraViewFrustrum : MonoBehaviour
{	
	public Color clr = new Color(0.1f, 0.14f, 0.8f, 0.5f);
	public void OnDrawGizmos()
	{	
		Gizmos.color= clr;
		float near 	= GetComponent<Camera>().nearClipPlane;
		if ( GetComponent<Camera>().orthographic )
		{
			// Orthographic cage
			Gizmos.DrawWireCube(
				transform.position + new Vector3(0,0,near/2),
			    new Vector3(
					(GetComponent<Camera>().orthographicSize*GetComponent<Camera>().aspect)*2, 
					GetComponent<Camera>().orthographicSize*2, 
					near));
		}
		else
		{
			// Perspective cage
			float angleTan 	= Mathf.Tan( GetComponent<Camera>().fieldOfView );
			Gizmos.DrawWireCube(
				transform.position + new Vector3(0,0,near/2), 
				new Vector3(
					(angleTan * near * GetComponent<Camera>().aspect)/2 , 
					(angleTan * near)/2, 
					near));
		}
	}
}