[Bf-committers] Collada importer/exporter kickout

[Sebastian]

There was a proposal once on the COLLADA mailing list to include 
constraints. It turned out that with COLLADA 1.5's kinematic model and 
the full MathML support for formulas nearly every use case could be 
handled. If you're interested and prepare a blend file we can handcraft 
a corresponding COLLADA file.

Sebastian




On 15.01.2012 15:10, Juan Linietsky wrote:
> The problem with importing/exporting of Collada and skeletons is not really
> that it doesn't match the internal representation.
> Animating 3D objects in a 3D Animation package is always done through euler
> angles, local or global, and that is easy to export
> seamlessly in Collada.
> But skeleton based models like characters almost always use IK or other
> sort of constraints which are impossible to convert back to euler due to
> gimbal lock issues, so the only way to reliably export skeletal animation
> is to export a full rotation snapshot either via a quaternion (which
> Collada does not support) or 4x3 matrix., and later optimize redundant
> keyframes to save storage space.
> So I think in short, it's the lack of support for constraints what makes
> Collada not very useful as an exchange format between DCCs, but yet it's
> still very useful for exporting to game engines.
>
> Juan
>
>
>
>
> On Sat, Jan 14, 2012 at 5:28 PM, Juha Mäki-Kanto<kiskosika at gmail.com>wrote:
>
>>
>>
>> The gist to me is that collada's transformations may not match a program's
>> internal representation and reinterpreting usually goes via collada data to
>> full matrix, possibly fix the matrix and then decomposite to curves. It's a
>> lossy conversion, key's should match but interpolation won't ->  you need to
>> bake/key every frame when importing the curves.
>>
>>
>>
>>
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