Rotating an object using the accelerometer from an Android device

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I’m currently trying to control the tilt of a simulated toy “airplane” with my android device, and seeing if I can implement tilt functionality. I’m just trying to rotate it along the Y axis at the moment.

My first implementation tried to rotate the object by adding the value from input.acceleration to the Y rotation.

  if(movement.normalizedDir.y >= 0.2 || movement.normalizedDir.y <=-0.2){
    transform.Rotate(0,movement.normalizedDir.y*Time.deltaTime*rotationSpeed*-1,0);
	}

This worked quite well, but I found out that it felt more intuitive if the “airplane” rotated towards the angle that I held my phone, rather than rotating faster the more I tilted the phone. I tended to hold it up towards the intended end rotation.

So then I’m looking for a way to rotate from my current rotation, towards the rotation I am holding my phone, over time. I was looking at Quaternion.Slerp, which needs two quaternions.

As my knowledge of quaternions is rather slim I was wondering if I could convert the vector from input.acceleration to a quaternion and somehow feed that to the end quaternion in slerp. Any alternative suggestions on how to solve it will of course be highly appreciated.

Sincerely

EvilNorwegian

1 Answer

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If you’re looking to match the angle at which you’re holding the phone, I’d use Input.gyro.attitude rather than linear acceleration. And that’s a quaternion anyway, so you’ll find slerping easier.