Calculate drift offset and replace rotation of a box

Scripting
1

Hey guys, i have this scenario:

I got rotation data from a gyro sensor (xyzw). In the first 5 seconds the data is drifting, but after that time it finds its position and the data is without drift.

So when the data is steady I want to calculate the offset from the current position to the original position and attach it back to the box, so I can use the Gyro but in the original position.

Does anybody know how to achieve that?

2

Let’s solve this by pretending the drift is happening in one dimension, then converting that logic to Quaternion functions.

You can store the initial rotation (A) in a Quaternion, then store the “post-drift” rotation (B) in a second Quaternion. Then the third important value is the current rotation (C). If these were numbers, you’d be able to calculate the current value of the number with

Final = C - (B - A)

You can use the * operator to combine rotations (which is analogous to adding numbers), and you have .Inverse to make a quaternion “negative”. So let’s slightly alter the formula to make this easier to convert:

Final = C + -(B + (-A) )

So let’s calculate the quaternion equivalent of -(B + (-A) ), which is:

(B * A.Inverse() ).Inverse()

Since this is never going to change after the drift period, store that result. Now every frame, you just need to:

transform.rotation = C * storedDriftResult;

So there’s a starting point - see if that accomplishes the result you’re looking for.

3

Hey StarManta, thanks for you’re answer. I will try it out!