FakeRenderCubemap

using UnityEngine;
using System.Collections;

public class FakeRenderCubemap : MonoBehaviour {
    public Cubemap cubemap;
    public float updateFrequency = .5f;
    private float lastUpdate = 0f;

    void Start() {
        FakeRenderCubemapFace[] children = transform.GetComponentsInChildren<FakeRenderCubemapFace> ();
        foreach (FakeRenderCubemapFace face in children) {
            face.updateFrequency = updateFrequency;
            face.cubemap = cubemap;
        }
    }

    void LateUpdate() {
        if (Time.time > lastUpdate + updateFrequency) {
            lastUpdate = Time.time;
            cubemap.Apply ();
        }
    }
}