Question by s3738367 · Sep 08, 2018 at 01:17 PM · camera vr webgl tracking gyro

Rotate object from headmovement using webvr?,Rotate object from head tracking movement? usingWEBVR asset store?

I'm trying to have a camera rotate around an object via headtracking movement. I'm using WEBVR as I want it to go on with all devices and on html. Two options:

Trying to move the camera around the object.. while object stays stationary if somehow I can make camera node go around using lookat on object but then camera node should be linked to headvr movement. I was able to do a normal lookat fixed point using mouse coordinates but not in VR.
Other option , keeping camera still and rotating the object via headmovement. This will also involve disabling movement of camera.

I'm fairly new to unity and coding, and then VR coding. I tried lookat functions and somehow try to put it in webvrcamera.cs script which comes in webvrassets. But nothing worked. Please help me get around a sol.

webvrcamera.cs_:

 private Camera cameraMain, cameraL, cameraR;
 private bool vrActive = false;

 [DllImport("__Internal")]
 private static extern void PostRender();

 private IEnumerator endOfFrame()
 {
     // Wait until end of frame to report back to WebVR browser to submit frame.
     yield return new WaitForEndOfFrame();
     PostRender ();
 }

 void OnEnable()
 {
     WebVRManager.Instance.OnVRChange += onVRChange;
     WebVRManager.Instance.OnHeadsetUpdate += onHeadsetUpdate;
     
     cameraMain = GameObject.Find("CameraMain").GetComponent<Camera>();
     cameraL = GameObject.Find("CameraL").GetComponent<Camera>();
     cameraR = GameObject.Find("CameraR").GetComponent<Camera>();

     cameraMain.transform.Translate(new Vector3(0, WebVRManager.Instance.DefaultHeight, 0));
 }

 void Update()
 {
     if (vrActive)
     {
         cameraMain.enabled = false;
         cameraL.enabled = true;
         cameraR.enabled = true;
     }
     else
     {
         cameraMain.enabled = true;
         cameraL.enabled = false;
         cameraR.enabled = false;
     }

     #if !UNITY_EDITOR && UNITY_WEBGL
     // Calls Javascript to Submit Frame to the browser WebVR API.
     StartCoroutine(endOfFrame());
     #endif
 }

 private void onVRChange(WebVRState state)
 {
     vrActive = state == WebVRState.ENABLED;
 }

 private void onHeadsetUpdate (
     Matrix4x4 leftProjectionMatrix,
     Matrix4x4 leftViewMatrix,
     Matrix4x4 rightProjectionMatrix,
     Matrix4x4 rightViewMatrix,
     Matrix4x4 sitStandMatrix)
 {
     if (vrActive)
     {
         SetTransformFromViewMatrix (cameraL.transform, leftViewMatrix * sitStandMatrix.inverse);
         cameraL.projectionMatrix = leftProjectionMatrix;
         SetTransformFromViewMatrix (cameraR.transform, rightViewMatrix * sitStandMatrix.inverse);
         cameraR.projectionMatrix = rightProjectionMatrix;
     }
 }

 // According to https://answers.unity.com/questions/402280/how-to-decompose-a-trs-matrix.html
 private void SetTransformFromViewMatrix(Transform transform, Matrix4x4 webVRViewMatrix)
 {
     Matrix4x4 trs = TransformViewMatrixToTRS(webVRViewMatrix);
     transform.localPosition = trs.GetColumn(3);
     transform.localRotation = Quaternion.LookRotation(trs.GetColumn(2), trs.GetColumn(1));
     transform.localScale = new Vector3(
         trs.GetColumn(0).magnitude,
         trs.GetColumn(1).magnitude,
         trs.GetColumn(2).magnitude
     );
 }

 // According to https://forum.unity.com/threads/reproducing-cameras-worldtocameramatrix.365645/#post-2367177
 private Matrix4x4 TransformViewMatrixToTRS(Matrix4x4 openGLViewMatrix)
 {
     openGLViewMatrix.m20 *= -1;
     openGLViewMatrix.m21 *= -1;
     openGLViewMatrix.m22 *= -1;
     openGLViewMatrix.m23 *= -1;
     return openGLViewMatrix.inverse;
 }

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