Unity3D基于陀螺仪实现VR相机功能的方法

using UnityEngine;
using System.Collections;
 
public class GyroController : MonoBehaviour
{
  // Fields
  private readonly Quaternion baseIdentity = Quaternion.Euler(90f, 0f, 0f);
  private Quaternion baseOrientation = Quaternion.Euler(90f, 0f, 0f);
  private Quaternion baseOrientationRotationFix = Quaternion.identity;
  private Quaternion calibration = Quaternion.identity;
  private Quaternion cameraBase = Quaternion.identity;
  private bool debug = true;
  public static bool gyroAvaiable;
  private bool gyroEnabled = true;
  private Quaternion gyroInitialRotation;
  public static bool gyroOff;
  private Quaternion initialRotation;
  private readonly Quaternion landscapeLeft = Quaternion.Euler(0f, 0f, -90f);
  private readonly Quaternion landscapeRight = Quaternion.Euler(0f, 0f, 90f);
  private const float lowPassFilterFactor = 0.1f;
  private Quaternion offsetRotation;
  private Quaternion referanceRotation = Quaternion.identity;
  private readonly Quaternion upsideDown = Quaternion.Euler(0f, 0f, 180f);
 
  // Methods
  private void AttachGyro()
  {
    this.gyroEnabled = true;
    this.ResetBaseOrientation();
    this.UpdateCalibration(true);
    this.UpdateCameraBaseRotation(true);
    this.RecalculateReferenceRotation();
  }
 
  private void Awake()
  {
    gyroAvaiable = SystemInfo.supportsGyroscope;
  }
 
  private static Quaternion ConvertRotation(Quaternion q)
  {
    return new Quaternion(q.x, q.y, -q.z, -q.w);
  }
 
  private void DetachGyro()
  {
    this.gyroEnabled = false;
  }
 
  private Quaternion GetRotFix()
  {
    return Quaternion.identity;
  }
 
  private void RecalculateReferenceRotation()
  {
    this.referanceRotation = Quaternion.Inverse(this.baseOrientation) * Quaternion.Inverse(this.calibration);
  }
 
  private void ResetBaseOrientation()
  {
    this.baseOrientationRotationFix = this.GetRotFix();
    this.baseOrientation = this.baseOrientationRotationFix * this.baseIdentity;
  }
 
  protected void Start()
  {
 
      Input.gyro.enabled = true;
      base.enabled = true;
    this.AttachGyro();
    this.initialRotation = base.transform.localRotation;
    this.gyroInitialRotation = Input.gyro.attitude;
  }
 
  private void Update()
  {
    gyroOff = PlayerPrefs.GetInt("gyro-off") == 1;
    if (this.gyroEnabled )
    {
      base.transform.localRotation = Quaternion.Slerp(base.transform.localRotation, this.cameraBase * (ConvertRotation(this.referanceRotation * Input.gyro.attitude) * this.GetRotFix()), 0.5f);//0.1f
    }
  }
 
  private void UpdateCalibration(bool onlyHorizontal)
  {
    if (onlyHorizontal)
    {
      Vector3 toDirection = (Vector3) (Input.gyro.attitude * -Vector3.forward);
      toDirection.z = 0f;
      if (toDirection == Vector3.zero)
      {
        this.calibration = Quaternion.identity;
      }
      else
      {
        this.calibration = Quaternion.FromToRotation((Vector3) (this.baseOrientationRotationFix * Vector3.up), toDirection);
      }
    }
    else
    {
      this.calibration = Input.gyro.attitude;
    }
  }
 
  private void UpdateCameraBaseRotation(bool onlyHorizontal)
  {
    if (onlyHorizontal)
    {
      Vector3 forward = base.transform.forward;
      forward.y = 0f;
      if (forward == Vector3.zero)
      {
        this.cameraBase = Quaternion.identity;
      }
      else
      {
        this.cameraBase = Quaternion.FromToRotation(Vector3.forward, forward);
      }
    }
    else
    {
      this.cameraBase = base.transform.rotation;
    }
  }
}