ModelRotator.cs

// Model Rotator 
// based on SimpleMouseRotator from unity utility

using System;
using UnityEngine;
using UnityEngine.EventSystems;

public class ModelRotator : MonoBehaviour
{
    public float rotationSpeedMouse = 2.0f;
    public float rotationSpeedVive = 200.0f;

    private Quaternion targetRotation;
    public float autoRotateSpeed = 720f;
    private float rotationStartTime = 0;
    private float rotationTime = 0.3f;

    private Vector3 previousVivePos;
    private bool rotating = false;

    void Start()
    {
        targetRotation = transform.localRotation;
    }

    private void Update()
    {
        if (UI.Core.instance.layoutSystem.activeScreen == UI.Screen.center) {
            
            InputDevice inputDevice = InputDeviceManager.instance.currentInputDevice;
            if (inputDevice.getDeviceType() == InputDeviceManager.InputDeviceType.Mouse) {
                // Let mouse handle rotation:
                if (Input.GetMouseButton (1) || Input.GetKey (KeyCode.M)) {
                    float inputH = -Input.GetAxis ("Mouse X");
                    float inputV = -Input.GetAxis ("Mouse Y");

                    Vector3 upVector = Camera.main.transform.up;
                    Vector3 rightVector = Camera.main.transform.right;
                    transform.RotateAround (transform.position, upVector, inputH * rotationSpeedMouse);
                    transform.RotateAround (transform.position, rightVector, -inputV * rotationSpeedMouse);

                    targetRotation = transform.localRotation;   // Make sure it doesn't auto-rotate back.
                }
            } else if( inputDevice.getDeviceType() == InputDeviceManager.InputDeviceType.ViveController ) {
                // Let left Vive controller handle rotation:
                LeftController lc = InputDeviceManager.instance.leftController;
                if (lc != null) {
                    UnityEngine.EventSystems.PointerEventData.FramePressState triggerState = lc.triggerButtonState;
                    if (triggerState == UnityEngine.EventSystems.PointerEventData.FramePressState.Pressed) {
                        rotating = true;
                        previousVivePos = lc.transform.localPosition;
                    } else if (triggerState == UnityEngine.EventSystems.PointerEventData.FramePressState.Released) {
                        rotating = false;
                        previousVivePos = new Vector3 (0, 0, 0);
                    }
                    if (rotating) {
                        Vector3 upVector = Camera.main.transform.up;
                        Vector3 rightVector = Camera.main.transform.right;
                        transform.RotateAround (transform.position, upVector, (previousVivePos.x - lc.transform.localPosition.x) * rotationSpeedVive);
                        transform.RotateAround (transform.position, rightVector, -(previousVivePos.y - lc.transform.localPosition.y) * rotationSpeedVive);
                        targetRotation = transform.localRotation;   // Make sure it doesn't auto-rotate back.
                        previousVivePos = lc.transform.localPosition;
                    }
                }
            }
        }

        // Slowly rotate towards target, if any:
        //float step =  Time.time;
        transform.localRotation = Quaternion.Slerp( transform.localRotation, targetRotation, (Time.time - rotationStartTime)/rotationTime );

    }

    public void setTargetOrientation( Quaternion orientation, float timeForRotation = 0f )
    {
        targetRotation = orientation;
        rotationStartTime = Time.time;
        if (timeForRotation == 0f) {
            transform.localRotation = orientation;
            rotationTime = 1f;  // Avoid division by zero
        } else {
            rotationTime = timeForRotation;
        }
    }
}