Well met!

This may seem like a rather simple thing, but I can't seem to figure it out or find an answer.

I'm trying to write an exporter for 3ds MAX, but it stores its rotations in quaternions while I need angles.

It does provide you with a function to convert them, which gives you bad angles at the edges.

A simple rotation around the Y axis jumps like this:

...
(quat -0.0222105 -0.706758 -0.0222105 0.706758)
(eulerAngles 90.0001 86.4 90.0001)

(quat 2.30405e-007 -0.707107 2.30405e-007 0.707107)
(eulerAngles 0 90 0)

(quat 0.0230636 -0.706731 0.0230636 0.706731)
(eulerAngles -90 86.2617 -90)
...

After some research I got told that that is the expected behavior. I tried to write my own conversion function and catch the bad angles, but failed. What exactly should I do to get the degrees?

I hope you can help me with this!

Thank you in advance and have a nice day!

You only really need a fairly basic understanding of what a Quaternion is to be able to use them effectively, and for animations, it's totally worthwhile to gain that understanding.

You only really need a fairly basic understanding of what a Quaternion is to be able to use them effectively, and for animations, it's totally worthwhile to gain that understanding.

You only really need a fairly basic understanding of what a Quaternion is to be able to use them effectively, and for animations, it's totally worthwhile to gain that understanding.

I had my animations implemented using Quaternions at first.

I am currently rewriting my whole animation code based on a model suggested by L. Spiro, and so far it works out awesome. The last thing I need to get right are the rotations.

Like she mentioned in her post, Quaternions are really slow compared to matrices. And the track based animation system requires me to know every single part of the world matrix in order to gain speed.

(http://www.gamedev.net/topic/659147-optimising-bone-based-animation/#entry5169156)

Because I need the single rotations for each axis in order for the track-based animation-system to work. (But there might be a way around that)

But if I'd convert it into a rotation-matrix, I'd still get the problem at the edges, wouldn't I?

But if I'd convert it into a rotation-matrix, I'd still get the problem at the edges, wouldn't I?

Why would you get "problems" at the "egdes" (what edges?) with rotation matrix?

Sounds like you really should re-investigate:
* what is a rotation matrix (how it works / what it represents mathematically)
* what is a quaternion (--||--)
* what is gimbal lock in regards of euler angles ( edit: http://en.wikipedia.org/wiki/Gimbal_lock )

But if I'd convert it into a rotation-matrix, I'd still get the problem at the edges, wouldn't I?

Why would you get "problems" at the "egdes" (what edges?) with rotation matrix?

Sounds like you really should re-investigate:
* what is a rotation matrix (how it works / what it represents mathematically)
* what is a quaternion (--||--)
* what is gimbal lock in regards of euler angles ( edit: http://en.wikipedia.org/wiki/Gimbal_lock )

I stated what the problem is in my first post.

I understand complex numbers and quaternions as well as where the problem is coming from (Which is, as I stated, the singularity in the conversion function).

I don't really care about the one degree beeing lost due to the gimbal lock.

But if I'd convert it into a rotation-matrix, I'd still get the problem at the edges, wouldn't I?

This was supposed to mean that the conversion problem that occurs when converting to degrees also would occur when converting to a matrix.

But if I'd convert it into a rotation-matrix, I'd still get the problem at the edges, wouldn't I?

This was supposed to mean that the conversion problem that occurs when converting to degrees also would occur when converting to a matrix.

If you really know quaternions, as you say, although I'm not convinced, then this may help you:

http://wscg.zcu.cz/wscg2012/short/a29-full.pdf

Dual quaternions are excellent for this, especially if you're rolling your own.

Also, don't use matrices (where you don't have to) until the very last moment just before you shove it into GL

And... where does degrees come into this? Is it something that comes from 3ds max?