How is maya camera film offset translated into nuke camera equivalent?

[丰]

I would like to write a maya camera exporter to nuke, but I don't know
how to translate maya camera's "film offset" attributes into nuke
camera's "translate u & v" in the Projection tab.
I did know it is possible to match the film offset attribute with the
nuke equivalent, because I had done it a couple of days before. But I
did it by adjusting the attribute, looking at the output image, and
compared the one rendered with maya.
nukeCam.translateU = mayaCam.horizontalFilmOffset/mayaCam.hfa did not
do the trick.

Sorry if there is any improper expression, for English is not my native tongue.
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2.6.32.26-175.fc12.x86_64

[Frank.Hill]

I would like to write a maya camera exporter to nuke, but I don't know
how to translate maya camera's "film offset" attributes into nuke
camera's "translate u & v" in the Projection tab.
I did know it is possible to match the film offset attribute with the

nuke equivalent, because I have done it days ago. But I had to do it
by adjusting the attribute, watching the output image, and
comparing it with the one rendered in maya.

nukeCam.translateU = mayaCam.horizontalFilmOffset/mayaCam.hfa did not
do the trick.

ps: It seems mail sent to python_in...@googlegroups.com did not
get posted to the list.

[Deke Kincaid]

BTW, nuke can read film offsets with fbx 2010 files.  If you want to write your converter though, Nuke uses NDC coordinates.  Here is the formula I use inside Nuke to read in maya film back offsets which you should be able to reverse engineer to export from inside Maya:

window translate u:  

(2/haperture)*(mayaFilmOffset.x*25.4)

window translate v:
(((root.format.h/root.format.w)*2)/vaperture)*(mayaFilmOffset.y*25.4)

set cut_paste_input [stack 0]
version 6.1 v3
push $cut_paste_input
Camera2 {
 vaperture 10.08453016
 win_translate {{(2/haperture)*(mayaFilmOffset.x*25.4)}
{(((root.format.h/root.format.w)*2)/vaperture)*(mayaFilmOffset.y*25.4)}}
 name Camera2
 selected true
 xpos 2082
 ypos -481
 addUserKnob {20 MayaCameraSettings}
 addUserKnob {12 mayaFilmOffset l "Maya Film Offset"}
 mayaFilmOffset {-0.5 -0.1}
}

-deke

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[丰]

Thank you deke. It's really helpful.
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2.6.32.26-175.fc12.x86_64

[rafal.k...@primefocusworld.com]

On Wednesday, July 20, 2011 9:13:20 AM UTC+1, dekekincaid.at.gmail dot com wrote:

> BTW, nuke can read film offsets with fbx 2010 files.

I have tried this with both binary and asci files in nuke 7 & 8 and the film projections offsets don't import into nuke....

can you remember how you did this?

[vladislav....@framestore.com]

Hi guys, sorry to bring this topic back.

How to export
window translate from Nuke to Maya?

Thanks a lot.

[Vladislav Akhtyrskiy]

Actually already did it)

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[adrian...@googlemail.com]

Vladislav - How did you do it?

[adrian...@googlemail.com]

Think I figured this out but haven't rigorously tested yet (Looked fine in viewport :D) - Just in case anyone else finds this thread with the same question of going from Nuke to Maya rather than the other way.

(Nuke window translate U * (Nuke horizontal aperture / 25.4)) / 2 = Maya Horizontal film offset

For V it's the same just substitute Nuke window translate U value for V value.

[Jeremy Beauchamp]

Anyone know the math for Maya Pre/post scale to Nuke window scale u/v? 

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