Screenshot.cs

using UnityEngine;
using System.Collections;
using System;

public class Screenshot : MonoBehaviour
{
    public GameObject OVcamera;
    public string path = "";
    private bool takeScreen = false;

    private SteamVR_TrackedController device;

    void Start()
    {
        //OVcamera = Camera.main.gameObject;
        device = GetComponent<SteamVR_TrackedController>();
        device.Gripped += Trigger;
    }

    void Trigger(object sender, ClickedEventArgs e)
    {
        takeScreen = true;
    }

    void LateUpdate()
    {

        if (takeScreen)
        {
            takeScreen = false;
            Debug.LogWarning ("Start Capture Screen");
            StartCoroutine(TakeScreenShot());
        }

    }

    // return file name
    string fileName(int width, int height)
    {
        return string.Format("screen_{0}x{1}_{2}.png",
            width, height,
            System.DateTime.Now.ToString("yyyy-MM-dd_HH-mm-ss"));
    }

    public IEnumerator TakeScreenShot()
    {
        Debug.LogWarning ("Capture Screen");
        yield return new WaitForEndOfFrame();

        Camera camOV = OVcamera.GetComponent<Camera>();

        RenderTexture currentRT = RenderTexture.active;

        RenderTexture.active = camOV.targetTexture;
        camOV.Render();
        Texture2D imageOverview = new Texture2D(camOV.targetTexture.width, camOV.targetTexture.height, TextureFormat.RGB24, false);
        imageOverview.ReadPixels(new Rect(0, 0, camOV.targetTexture.width, camOV.targetTexture.height), 0, 0);
        imageOverview.Apply();
        RenderTexture.active = currentRT;


        // Encode texture into PNG
        byte[] bytes = imageOverview.EncodeToPNG();

        // save in memory
        string filename = fileName(Convert.ToInt32(imageOverview.width), Convert.ToInt32(imageOverview.height));
        path = filename;

        System.IO.File.WriteAllBytes(path, bytes);
    }
}