Need help with accelerometer low pass filter

Hi all,

Bit of a noob here. Would love your help. My game is incredibly shaky/jerky when on tilt mode. Have tried everything I've found online and still nothing has worked. Wondering if someone can take a look at the code I'm currently using for tilt mode and add a way for a low pass filter to work so that tilt mode is enjoyable, and not cause seizures lol. Thanks for your time!

if (playerObject)
{
if (Application.isMobilePlatform )
{
if (playerObject.useTiltControls == true)
{
playerObject.turnDirection = Vector3.Lerp(playerObject.turnDirection, new Vector3(Input.acceleration.x, Input.acceleration.z + 0.2f), Time.deltaTime * playerObject.turnSpeed);
}
else if (playerObject.useMouseControls == true)
{
if (Input.GetButton("Fire1")) playerObject.turnDirection = Vector3.Lerp(playerObject.turnDirection, new Vector3((Input.mousePosition.x - Screen.width * 0.5f) / Screen.width * 2, (Input.mousePosition.y - Screen.height * 0.3f) / Screen.height * 1.4f), Time.deltaTime * playerObject.turnSpeed * 0.25f);

playerObject.turnDirection = Vector3.ClampMagnitude(playerObject.turnDirection, 1);

//gameCanvas.Find("Text").GetComponent<Text>().text = new Vector3(playerObject.turnDirection.x, playerObject.turnDirection.y).ToString();
}

// Limit the position of the camera
if (playerObject.transform.position.y > playerObject.heightLimit)
{
playerObject.turnDirection = Vector3.Lerp(playerObject.turnDirection, new Vector3(playerObject.turnDirection.x, 0), Time.deltaTime * playerObject.turnSpeed * 0.2f);
}
}
else
{
// Using the mouse for movement
if (usingMouse == true)
{
playerObject.turnDirection = Vector3.Lerp(playerObject.turnDirection, new Vector3((Input.mousePosition.x - Screen.width * 0.5f) / Screen.width * 2, (Input.mousePosition.y - Screen.height * 0.5f) / Screen.height * 2), Time.deltaTime * playerObject.turnSpeed);
}
else
{
playerObject.turnDirection = Vector3.Lerp(playerObject.turnDirection, new Vector3(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical")), Time.deltaTime * playerObject.turnSpeed * 0.1f);
}
}
}
}
}
}

 

A simple lowpass filter would be a moving average. you save x past acceleration vectors and average them. You could also try giving them different weights, so the more recent ones have a greater influence

 

@mrmathis

I'm not quite sure how to do that. I watched a video on youtube which showed adding weights and so on, but I'm not getting different results.

What could I add to: playerObject.turnDirection = Vector2.Lerp(playerObject.turnDirection, new Vector2(Input.acceleration.x, Input.acceleration.z + 0.2f), Time.deltaTime * playerObject.turnSpeed);

to stabilize this?

 

never mind, got it working.

 

Here is an example:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class SmoothAccelerometer : MonoBehaviour
4. {
5.     [SerializeField] private int _numSamples;
6.     [SerializeField] private AnimationCurve _weightCurve;
7.  
8.     private Vector3[] _samples;
9.     private float[] _weights;
10.     private float _weightSum;
11.     private int _currentSample;
12.     private Vector3 _acceleration;
13.  
14.     public Vector3 acceleration
15.     {
16.         get { return _acceleration; }
17.     }
18.  
19.     private void Awake()
20.     {
21.         _samples = new Vector3[_numSamples];
22.         _weights = new float[_numSamples];
23.         _weightSum = 0;
24.         for (int i = 0; i < _numSamples; i++)
25.         {
26.             _samples[i] = Vector3.zero;
27.             _weights[i] = _weightCurve.Evaluate(1f - 1f / _numSamples * i);
28.             _weightSum += _weights[i];
29.         }
30.     }
31.  
32.     void Update ()
33.     {
34.         _samples[_currentSample] = Input.acceleration;
35.        
36.         _acceleration = Vector3.zero;
37.         int index;
38.         for (int i = 0; i < _numSamples; i++)
39.         {
40.             index = _currentSample - i;
41.             if (index < 0)
42.                 index = _numSamples - (i - _currentSample);
43.             _acceleration += _samples[index] * _weights[index];
44.         }
45.         _acceleration /= _weightSum;
46.         _currentSample = ++_currentSample % _numSamples;
47.     }
48. }

Top 3 are unsmoothed: