void Update()
    {
        // calcul de la progression du fondu au noir
        float oldProgression = blackoutProgression;

        if (viewmasterObject.IsGrabbed())
        {
            float distance = 999;
            foreach (Transform anchorPoint in viewmasterObjectAnchors)
            {
                distance = Mathf.Min(distance, Vector3.Distance(anchorPoint.position, Camera.main.transform.position));
            }
            float range = maxDistance - minDistance;
            blackoutProgression = (distance - minDistance) / range;
        }
        else
        {
            blackoutProgression += Time.deltaTime;
        }
        blackoutProgression = Mathf.Clamp(blackoutProgression, 0, 1);
        Color matCol = blackoutMesh.material.color;

        matCol.a = 1 - blackoutProgression * .9f;
        blackoutMesh.material.color = matCol;

        renderCam.enabled = blackoutProgression <= 1;
        if (blackoutProgression < 1 && oldProgression >= 1)
        {
            // calcul de la position de l'image en fonction de la tête du joueur
            portraitOrientation.localPosition = renderCam.transform.localPosition + new Vector3(0, -.1f, 0);
            portraitOrientation.localRotation = Quaternion.Euler(
                portraitOrientation.localEulerAngles.x,
                renderCam.transform.localEulerAngles.y,
                portraitOrientation.localEulerAngles.z);
            // désactivation TP
            teleportHandler.enabled = false;
        }
        else if (blackoutProgression >= 1 && oldProgression < 1)
        {
            teleportHandler.enabled = true;
        }

        // calcul de la progression du fondu de l'image
        if (blackoutProgression <= 0)
        {
            canvasProgression += Time.deltaTime;
        }
        else
        {
            canvasProgression -= Time.deltaTime * 7;
        }

        canvasProgression    = Mathf.Clamp(canvasProgression, 0, 1);
        portraitsGroup.alpha = canvasProgression;

        if (blackoutProgression <= 0)
        {
            float angleBetweenPictures = 30;
            if (currentClip != null)
            {
                angleBetweenPictures = 180f / currentClip.images.Length;
            }
            // float angleBetweenPictures = 30; // à n'utiliser que si l'autre n'est pas assez intuitif

            GameObject grabbingObj = viewmasterObject.GetGrabbingObject();
            if (grabbingObj != null)
            {
                VRTK.VRTK_ControllerEvents eventCtrl = grabbingObj.GetComponent <VRTK.VRTK_ControllerEvents>();
                lastControllerActions = grabbingObj.GetComponent <VRTK.VRTK_ControllerActions>();
                if (eventCtrl != null)
                {
                    // on est en train de visionner l'image, on récupère la manette en train de tenir le VM afin de récupérer les swipes sur le pavé tactile
                    eventCtrl.axisFidelity = 5;
                    bool wasPressing = pressingButton;
                    pressingButton = eventCtrl.IsButtonPressed(VRTK.VRTK_ControllerEvents.ButtonAlias.Touchpad_Touch);
                    if (pressingButton && !wasPressing)
                    {
                        lastRotation = eventCtrl.GetTouchpadAxisAngle();
                    }
                    float trigger = eventCtrl.GetTriggerAxis();
                    if (trigger != 1)
                    {
                        ignoreTrigger = false;
                    }
                    if (trigger == 1 && !ignoreTrigger)
                    {
                        ignoreTrigger         = true;
                        autoMoveToNextPicture = true;
                        StartCoroutine(TriggerHapticCoroutine());
                    }
                    if (pressingButton && trigger == 0 && false)
                    {
                        float oldPortraitRotation = currentPortraitRotation;
                        // en train de faire un swipe
                        float currentPadRotation = eventCtrl.GetTouchpadAxisAngle();
                        if (lastRotation - currentPadRotation < 180 && lastRotation - currentPadRotation > -180)
                        {
                            currentPortraitRotation += (lastRotation - currentPadRotation) * rotateSensitivity;
                        }
                        if (lastControllerActions != null && ((int)(currentPadRotation) / 35) != ((int)(lastRotation) / 35))
                        {
                            lastControllerActions.TriggerHapticPulse(.05f);
                        }
                        if (currentPortraitRotation > angleBetweenPictures / 2 && oldPortraitRotation < angleBetweenPictures / 2)
                        {
                            StartCoroutine(TriggerHapticCoroutine());
                        }
                        if (currentPortraitRotation < -angleBetweenPictures / 2 && oldPortraitRotation > -angleBetweenPictures / 2)
                        {
                            StartCoroutine(TriggerHapticCoroutine());
                        }
                        lastRotation = currentPadRotation;
                    }
                }
            }

            if (!pressingButton || autoMoveToNextPicture)
            {
                if (autoMoveToNextPicture)
                {
                    currentPortraitRotation += Time.deltaTime * (angleBetweenPictures + .01f - currentPortraitRotation) * 10;
                }
                else
                {
                    // retour à l'image la plus proche
                    if (currentPortraitRotation > angleBetweenPictures / 2)
                    {
                        currentPortraitRotation += Time.deltaTime * (angleBetweenPictures + .01f - currentPortraitRotation) * 10;
                    }
                    else if (currentPortraitRotation < -angleBetweenPictures / 2)
                    {
                        currentPortraitRotation += Time.deltaTime * -(angleBetweenPictures + .01f + currentPortraitRotation) * 10;
                    }
                    else
                    {
                        currentPortraitRotation -= Time.deltaTime * currentPortraitRotation * 10;
                    }
                }
            }

            if (currentPortraitRotation > angleBetweenPictures)
            {
                currentPortraitRotation -= angleBetweenPictures;
                nextImage();
            }
            if (currentPortraitRotation < -angleBetweenPictures)
            {
                currentPortraitRotation += angleBetweenPictures;
                previousImage();
            }

            // rotation de l'image
            leftImageTransform.transform.localRotation      = Quaternion.Euler(0, 0, currentPortraitRotation);
            rightImageTransform.transform.localRotation     = Quaternion.Euler(0, 0, currentPortraitRotation);
            leftImageTransformNext.transform.localRotation  = Quaternion.Euler(0, 0, currentPortraitRotation + angleBetweenPictures);
            leftImageTransformPrev.transform.localRotation  = Quaternion.Euler(0, 0, currentPortraitRotation - angleBetweenPictures);
            rightImageTransformNext.transform.localRotation = Quaternion.Euler(0, 0, currentPortraitRotation + angleBetweenPictures);
            rightImageTransformPrev.transform.localRotation = Quaternion.Euler(0, 0, currentPortraitRotation - angleBetweenPictures);
        }
        else
        {
            // rotation du disque du grabbable, pas de la vue.

            GameObject grabbingObj = viewmasterObject.GetGrabbingObject();
            if (grabbingObj != null)
            {
                VRTK.VRTK_ControllerEvents eventCtrl = grabbingObj.GetComponent <VRTK.VRTK_ControllerEvents>();
                lastControllerActions = grabbingObj.GetComponent <VRTK.VRTK_ControllerActions>();
                if (eventCtrl != null)
                {
                    // on est en train de visionner l'image, on récupère la manette en train de tenir le VM afin de récupérer les swipes sur le pavé tactile
                    eventCtrl.axisFidelity = 5;
                    bool wasPressing = pressingButton;
                    pressingButton = eventCtrl.IsButtonPressed(VRTK.VRTK_ControllerEvents.ButtonAlias.Touchpad_Touch);
                    if (pressingButton && !wasPressing)
                    {
                        lastRotation = eventCtrl.GetTouchpadAxisAngle();
                    }
                    if (pressingButton && false)
                    {
                        // en train de faire un swipe
                        float currentPadRotation = eventCtrl.GetTouchpadAxisAngle();
                        if (lastRotation - currentPadRotation < 180 && lastRotation - currentPadRotation > -180)
                        {
                            currentClipRotation += (lastRotation - currentPadRotation) * rotateSensitivity;
                        }
                        if (lastControllerActions != null && ((int)(currentPadRotation) / 275) != ((int)(lastRotation) / 275))
                        {
                            triggerAnimator.SetTrigger("Trigger");
                        }
                        lastRotation = currentPadRotation;

                        viewmasterGrabbableClipRotation.transform.localRotation = Quaternion.Euler(currentClipRotation, 0, 0);
                    }
                }
            }
        }
    }