[Bf-committers] FBX camera

Ejner Fergo ejnersan at gmail.com
Wed Nov 16 20:07:36 CET 2011

```Heh, I knew I would be in over my head by asking, but had to try ;) My
method is a primitive trial and error, no deeper thoughts about matrix
calculations! O_o

I'm not surprised that using Vector((0.0, 0.0, 0.0)) is fishy, but hey
it worked! It's hard for me to believe that Nuke and Houdini don't
read FBX correctly, since I have big respect for those two apps
specifically. Not sure about the conventions but that's probably it.
Will try again, there has to be a way that works for all apps!

BTW, do you agree that frames should start from 1 instead of 0 ?

On Wed, Nov 16, 2011 at 6:47 PM, Campbell Barton <ideasman42 at gmail.com> wrote:
> On Thu, Nov 17, 2011 at 4:28 AM, Ejner Fergo <ejnersan at gmail.com> wrote:
>> Hi Campbell,
>>
>> Thank you for committing the patch!
>>
>> I've been looking more into the (local) rotation problem in Nuke &
>> Houdini. Turns out a small change is needed on line 404, but the
>> change is also needed for lamps, so posted the changes here:
>> http://www.pasteall.org/26478
>>
>> Basically Vector((0.0, 1.0, 0.0)) needs to be Vector((0.0, 0.0, 0.0)).
>
> This looks wrong, the vector is being used as an axis for another
> rotation matrix, passing a zero length axis to Matrix.Rotation
> probably just makes the matrix a unit matrix.
>
>                    y = matrix_rot * Vector((0.0, 1.0, 0.0))
>                    matrix_rot = Matrix.Rotation(math.pi / 2.0, 3, y)
> * matrix_rot
>
> could be replaced with...
>                    matrix_rot = Matrix().to_3x3() * matrix_rot
> or :) ...
>                    matrix_rot = matrix_rot
>
> This needs further investigation & testing with different apps :S, its
> possible Nuke & Houdini dont read FBX correctly too (or assume certain
> conventions).
>
>> This of course mess things up in Maya (and C4D)... FBX is such a
>> stupid format, irritating that Autodesk is pushing it!
>>
>> Another thing: Can we please change the frame range to not be -1? All
>> apps start from frame 1, even Maya has changed from 0 to 1.
>>
>> Any thoughts on all this? And can you point me in a direction on how
>> to animate settings?
>>
>>
>> Best regards,
>> Ejner
>> _______________________________________________
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>> Bf-committers at blender.org
>> http://lists.blender.org/mailman/listinfo/bf-committers
>>
>
>
>
> --
> - Campbell
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```