Rotation and Angular Velocity Elementary Problem

[Buzzer]

Can someone help me understand what I am doing wrong, it seems so simple...

I use a quaternion to store the current orientation of the object ( relative to the world axes). I use another quaternion to store the angular velocity (right now, a just something I entered in the source). Every frame, I go:

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quaternionRotation += quaternionAngularVelocity * floatFrameTime;

Then I convert the quaternion into a world matrix and render the thing.

But this doesn't work.

I thought the whole advantage of quaternions is that the above line made sense. Can anyone point out what I'm doing wrong (other than being an idiot)?

[dog]

I think you want:

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quaternionRotation = Normalize(quaternionRotation + quaternionRotation * Quaternion(Vector4(angularVelocity) * (0.5f * floatFrameTime)));

[Buzzer]

This code seems the same, with the exception that:

• floatFrameTime was changed to 0.5 * floatFrameTime

• We normalize the quaternion, which I tried and doesn't seem to help.

[Dirk Gregorius]

For me your code and dogs post don't look the same. I suggest to look at Bullet and see how it works. I think Erwin has two implementations to integrate the angular velocity.

[Buzzer]

Missed the "quaternionRotation *" in "quaternionRotation * Quaternion(Vector4(angularVelocity)"

Thanks dog, it actually works quite well.
Sorry for doubting you.