arfoundation-samples/Assets/Scenes/CameraGrain/CameraGrain.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.XR.ARFoundation;

public class CameraGrain: MonoBehaviour
{
    [SerializeField]
    ARCameraManager m_CameraManager;
    public ARCameraManager cameraManager
    {
        get { return m_CameraManager; }
        set { m_CameraManager = value; }
    }

    Renderer m_Renderer;

    void Start()
    {
        if(m_CameraManager == null)
        {
            m_CameraManager = FindObjectOfType (typeof(ARCameraManager)) as ARCameraManager;
        }

        m_Renderer = GetComponent<Renderer>();
        m_CameraManager.frameReceived += OnReceivedFrame;
    }

    void OnDisable()
    {
        m_CameraManager.frameReceived -= OnReceivedFrame;
    }

    void OnReceivedFrame(ARCameraFrameEventArgs eventArgs){
        if(m_Renderer != null && eventArgs.cameraGrainTexture != null)
        {
            m_Renderer.material.SetTexture("_NoiseTex", eventArgs.cameraGrainTexture);
            m_Renderer.material.SetFloat("_NoiseIntensity", eventArgs.noiseIntensity);
        }
    }
}