Getting Angular Velocity relative to craft. (ΔPitch, ΔRoll, ΔHeading).

[c4ooo]

How do i orient a craft's angularVelocity vector to extract the ΔPitch, ΔRoll, ΔHeading? 

Mechjeb does this to orient the attitude vector to get the pitch roll and heading:

            Vector3d CoM, north, up;
            Quaternion rotationSurface;
            CoM = Vessel.CoM;
            up = (CoM - Vessel.mainBody.position).normalized;
            north = Vector3d.Exclude(up, (Vessel.mainBody.position + Vessel.mainBody.transform.up * (float)Vessel.mainBody.Radius) - CoM).normalized;

            rotationSurface = Quaternion.LookRotation(north, up);

            Vector3d attitude = Quaternion.Inverse(Quaternion.Euler(90, 0, 0) * Quaternion.Inverse(Vessel.GetTransform().rotation) * rotationSurface).eulerAngles;

However doing something similar but replacing Vessel.GetTransform().rotation with Vessel.angularVelocity results in what seems like meaningless numbers.

[sarbian]

Have you tried ?

Vector3d w = Quaternion.Inverse(vessel.ReferenceTransform.rotation) * vessel.angularVelocity * Mathf.Rad2Deg;

 

[c4ooo]

8 hours ago, sarbian said:

Have you tried ?

Vector3d w = Quaternion.Inverse(vessel.ReferenceTransform.rotation) * vessel.angularVelocity * Mathf.Rad2Deg;

 

The output vector's value's seem kinda meaningless

[Benjamin Kerman]

@c4ooo so the code Sarbin has provided is not really what you think it might be, which might be a direction. What that should give you is the offset (in degrees) from your "forward" (prograde) vector. If you're pointing prograde, I would expect it to be somewhere around <±180,±180,±180>, and pointing prograde, <0,0,0>.

You'll have to do some testing to figure out what "direction" each of the different numbers corresponds to in terms of the pitch, roll, and yaw (the vector should contain, if I am correct, each of those values from either [-90,90] or [0,180], probably the first one). 

If you'd like some more help with this, just post here with some of the output values and we can help you figure out what they might mean. 

Edited September 12, 2018 by Benjamin Kerman
Fixed vector ranges from 90->180

[c4ooo]

@Benjamin Kerman This is what i get when i tried rolling the vessel: (IDK why but Vector3d.ToString() makes it a rainbow...) https://i.imgur.com/fZkVZuo.png

Next i tried pitching the vessel down (harder to do accurately then rolling) and got this: https://i.imgur.com/vOJGRm6.png

Edited September 12, 2018 by c4ooo