[Bf-committers] COLLADA Node Transform

Recep Aslantas info at recp.me
Wed Nov 2 12:11:14 CET 2016


Hello,

I'm working on COLLADA/glTF library, also I'm writing a viewer/renderer to validate my progress and simplify usage of library,
as I promised I'll announce here after initial public release

My collada renderer (OpenGL Y_UP) renders correctly Blender exported COLLADA (seems same with Blender renderer),
There are three option to export Blender transform (export -> COLLADA Options)

I dont understand that why there is **Both** option, this exports affine transform matrix with individual transforms
so this meens that node will transform twice with same model matrix

My renderer multiplies all matrices, individual transforms (rotate, scale..) into one final matrix with exported order
my renderer can render correctly with 'Matrix' and 'TransRotLoc' except 'Both' option. 

COLLADA 1.5 spec says (about Node->transforms):
transformation_elements:  Any combination of the following transformation elements:

lookat
matrix
rotate
scale
skew
translate

Occurrences: 0 or more


So it does not say that if matrix is exists then skip other individual transforms or it is not clear what to do.

With 'Both' option Apple Quicklook/Preview also renders incorrectly, probably applying same transform twice 

Any ideas?


Thanks

- Recep Aslantas


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