Google Cardboard - how to face the same way when changing scenes?

Question

I'm creating a VR game, where if a user looks at a button, a scene will change.

The problem is that if I load a new scene using SceneManager, the direction that the user is facing resets, making it the new forward. For example, I have a quit button located behind the user. If they look at it, a new scene will load, but the new "forward" will be behind them, causing them to have to completely turn around in order for their body to face forward again.

I looked online and came across this post here but this was in Unity 4. It talks about commenting out Recenter() and device.Reset()

I have repeated the steps in Unity 5 (the version I am using) but this has no effect. I cannot see a device.Reset() piece of code in the Unity 5 Google Cardboard scripts either.

How can I keep facing the same direction when I load a new scene from a current scene in play mode?

Thanks!

Answer 1

Simply store the All the Camera's position and rotation values on exit. Load them in the Start function. I did something similar about a year ago and will share the script. Just attach it to any GameObject in the scene. Make sure to put cameras in each slot. Move the camera then exit the scene. It should hold the position of all the cameras next time you play again.

If it stops working, call the reset() function ONCE to reset the saved data then comment it out. It should only be called when it stops working which never happened to me.

#define USEWITHSECENE

using UnityEngine;
using System.Collections;

public class VRCAMRESTORE : MonoBehaviour
{

    [System.Serializable]
    class VRInfo
    {
        //Transform Info
        [SerializeField]
        public Vector3 mainCameraPos;
        [SerializeField]
        public Vector3 mainCameraLeftPos;
        [SerializeField]
        public Vector3 mainCameraRightPos;
        [SerializeField]
        public Vector3 reticleUnderMainCameraPos;

        [SerializeField]
        public Vector3 PreRenderCameraUnderStereoRenderPos;
        [SerializeField]
        public Vector3 PostRenderCameraUnderStereoRenderPos;

        //Rotation Info
        [SerializeField]
        public Quaternion mainCameraRot;
        [SerializeField]
        public Quaternion mainCameraLeftRot;
        [SerializeField]
        public Quaternion mainCameraRightRot;
        [SerializeField]
        public Quaternion reticleUnderMainCameraRot;

        [SerializeField]
        public Quaternion PreRenderCameraUnderStereoRenderRot;
        [SerializeField]
        public Quaternion PostRenderCameraUnderStereoRenderRot;
    }


    public Camera mainCamera;
    public Camera mainCameraLeft;
    public Camera mainCameraRight;
    public GameObject reticleUnderMainCamera;

    public Camera PreRenderCameraUnderStereoRender;
    public Camera PostRenderCameraUnderStereoRender;

    private VRInfo vrInfo = null;
    private Transform c1, c2, c3, c4, c5, c6;

    //Use this for initialization
    void Start()
    {
        intitTransform();
        vrInfo = new VRInfo();

        //check if vrInfo exist
        string savedJsonValue = PlayerPrefs.GetString("vrInfo");
        if (savedJsonValue == null)
        {
            updateCamTransform();
            return;
        }


        //Convert back to class
        vrInfo = JsonUtility.FromJson<VRInfo>(savedJsonValue);

        //If Null, dont load the saved location
        if (vrInfo == null)
        {
            updateCamTransform();
            return;
        }

        //Load Aettings from the Savings
        loadTransform();
    }

    public void reset()
    {
        PlayerPrefs.DeleteKey("vrInfo");
    }

    void intitTransform()
    {
        c1 = mainCamera.GetComponent<Transform>();
        c2 = mainCameraLeft.GetComponent<Transform>();
        c3 = mainCameraRight.GetComponent<Transform>();
        c4 = reticleUnderMainCamera.GetComponent<Transform>();
        c5 = PreRenderCameraUnderStereoRender.GetComponent<Transform>();
        c6 = PostRenderCameraUnderStereoRender.GetComponent<Transform>();
    }

    private void loadTransform()
    {
        c1.position = vrInfo.mainCameraPos;
        c1.rotation = vrInfo.mainCameraRot;

        c2.position = vrInfo.mainCameraLeftPos;
        c2.rotation = vrInfo.mainCameraLeftRot;

        c3.position = vrInfo.mainCameraRightPos;
        c3.rotation = vrInfo.mainCameraRightRot;

        c4.position = vrInfo.reticleUnderMainCameraPos;
        c4.rotation = vrInfo.reticleUnderMainCameraRot;

        c5.position = vrInfo.PreRenderCameraUnderStereoRenderPos;
        c5.rotation = vrInfo.PreRenderCameraUnderStereoRenderRot;

        c6.position = vrInfo.PostRenderCameraUnderStereoRenderPos;
        c6.rotation = vrInfo.PostRenderCameraUnderStereoRenderRot;
    }

    bool firstRun = true;

    private void updateCamTransform()
    {
        //Prevents vrInfo == null from running every frame
        if (firstRun)
        {
            firstRun = false;
            if (vrInfo == null)
            {
                vrInfo = new VRInfo();
            }
        }

        vrInfo.mainCameraPos = c1.position;
        vrInfo.mainCameraRot = c1.rotation;

        vrInfo.mainCameraLeftPos = c2.position;
        vrInfo.mainCameraLeftRot = c2.rotation;

        vrInfo.mainCameraRightPos = c3.position;
        vrInfo.mainCameraRightRot = c3.rotation;

        vrInfo.reticleUnderMainCameraPos = c4.position;
        vrInfo.reticleUnderMainCameraRot = c4.rotation;

        vrInfo.PreRenderCameraUnderStereoRenderPos = c5.position;
        vrInfo.PreRenderCameraUnderStereoRenderRot = c5.rotation;

        vrInfo.PostRenderCameraUnderStereoRenderPos = c6.position;
        vrInfo.PostRenderCameraUnderStereoRenderRot = c6.rotation;
    }

    void saveToDrive()
    {
        string json = JsonUtility.ToJson(vrInfo);
        PlayerPrefs.SetString("vrInfo", json);
        PlayerPrefs.Save();
        Debug.Log(json);
        Debug.Log("Quit");
    }

#if USEWITHSECENE
    void Update()
    {
        updateCamTransform();
    }

    void OnDisable()
    {
        saveToDrive();
    }
#else
    //For iOS
#if UNITY_IOS
    public void OnApplicationPause(bool pauseStatus)
    {
        if (pauseStatus)
        {
            //Convert to Json and Save
            updateCamTransform();
            saveToDrive();
        }
    }
#else
    //For Other Devices 
    public void OnApplicationQuit()
    {
        //Convert to Json and Save
        updateCamTransform();
        saveToDrive();
    }
#endif
#endif
}