[Bf-committers] Variable global up-axis

Wahooney wahooney at wahooney.net
Sun Jul 18 00:34:26 CEST 2010

Hi all,

Are there plans to allow Blender to have a variable/user settable up-axis?

Right now there is a problem when exporting from Blender to a y-up 
application (Unity3D in my case, but Maya is another example). Simply 
rotating everything 90 degrees about the x-axis does NOT fix the 
problem, all it does is pollute your transforms; something that becomes 
a PITA when dealing with game development.

A full matrix transposition needs to occur to get the correct results 
(in the case of swapping between z-up and y-up the 2nd and 3rd columns 
of the transform matrix need to be swapped, as well as the 2nd and 3rd 

I see that Maya has (or at least had last time I used it) a user 
settable up-axis, so this does seem to be something that will be useful 
in production situations.

I have tried to fix this problem myself in the FBX exporter, but so far 
it has been quite a challenge, given the size of the fbx exporter and 
the number of places that matrices need to be transposed. I am hoping 
that an official and proper inplementation might be somewhere on the 



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