[Bf-funboard] Eular rotation vs Quarternion rotation

[Stefan Andersson]

Exactly where do you get this "Eulers won't work for character
animation."??? it baffles me that you would make such a statement. I
need a example of this where it doesn't work.
First of all, all major animation packages (not just maya) uses Euler
rotations. Reason being that it's easy for the animator to control,
with the hurdle that you need to watch out for gimbal lock, but you
rather have that "threat" hanging over you than working with Quat
rotations.

Secondly, maya users complain about maya because it lacks logic and
its buggy for being a software that costs $$$$.

Thirdly, I'm not arrogant to say that programmers like Quats more than
Eulers. Would you or would you not agree that a programmer would think
that Quats are a "nicer implementation or a mathematical problem".
Gimbal Lock is virtualy gone with Quats... yes.. but to what price??
it IS a programmers solution to the problem, and the animator still
choses Eulers over Quats. And if your animators were screaming about
Gimbal Locks, they should have been talking to their TD instead of
screaming in mid-air.

I think it's needed that we get Euler rotations in Blender, and if I
wanted workarounds... well... I would use Maya at home as well :)

regards
stefan andersson




On Jan 20, 2008 8:49 PM, Bassam Kurdali <bkurdali at freefactory.org> wrote:
> Eulers won't work for character animation.
> But, could be OK to have switchable types (i.e. you can make a bone a "euler bone" or a "quat bone") quats would be good for 90% of character animation, and eulers would be good for wheels/geers/spinning things.
>
> We could also ask that quats could be editable as eulers- the IPO editor can pretend/lie to us :) and show eulers. Again , this should be optional. Animation master has a scheme like this.
> The one thing that could be a problem is the conversion from quat to euler. they are not one to one, but I think it is doable with some limitations.
> The last bit is similar to Horace's suggestion, and is what is doable in Animation Master (hash's animation package). I don't know about Maya, but just because "Maya does X" doesn't mean it's right (it might be) - Maya users often complain about stuff Maya does wrong.
>
> It's a bit arrogant to say quaternions are there for the benefit of the programer. I was animating in the past in euler only packages, and *everybody* was screaming about gimbal lock. That's why programmers gave us quaternions, and gimbal lock is virtually gone.
> Yes, it might be a huge problem for the coders depending on the code base. I wouldn't force this as a primary problem (it's more "it would be nice" than "it is needed") because we have workarounds.
>
> Bassam
>
>
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