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View Full Version : Problems using FBX out of Maya to send camera data to Lightwave



phillydee
03-17-2016, 09:55 AM
Hi:

A problem I'm faced with, that is using FBX to export camera that's at a custom resolution (1920x804, V-film aperature at 0.5906" (this rounds out to .591), focal length 55mm). Exporting these settings into Lightwave causes the focal length to be correct at 1920x804, however the "Frame" value is not at .5906", instead it loads at .4396" with the focal length arriving at 55mm. this does not give a pixel to pixel match, and when I change the frame value in Lightwave to 0.5906", the focal length jumps to 73.9mm.

Obviously, I can use info provided here http://planetside.co.uk/terragen/dev/tgcamera.html to script in some custom data to send over to Lightwave, and envelope that into the zoom factor env but every bone in my body is cringing with this thought. Any idea on how I can get a perfect camera match From Maya? The interchange is great but the camera zoom factor issue is really causing some concern.

ernpchan
03-17-2016, 11:11 PM
To get the frame size from the Maya settings do (HFA / 16) * 9. *

phillydee
03-18-2016, 12:07 AM
Thanks, so if I was using 2.39:1, I'd change the 16 and 9 out to the correct ratio? At what (decimal) point would this be accurate enough? I guess I can do some tests.

xevious2501
03-13-2018, 08:06 AM
Thanks, so if I was using 2.39:1, I'd change the 16 and 9 out to the correct ratio? At what (decimal) point would this be accurate enough? I guess I can do some tests.

So.. ive run into the same issue several times between Maya and Lw, when loading an FBX between the two.

Maya has all this Film Back info Lw seems not to have.

In my case.
We've had some footage tracked in BOujou and exported to maya via FBX
The track looks perfect in Maya, Background plates matching perfectly with the tracked nulls, but when importing into LW, somehow the data is thrown off in overal scale and position.
Ive tried several revisions of FBX, including spitting the data out of maya itself via fbx and the results are the same.

any news as to your solution? And please im not a math wiz at all. so if ya got anything please, explain in baby steps.

jwiede
03-13-2018, 12:04 PM
LW2018's handling of FBX camera info just feels broken, like it's ignoring or dropping a bunch of the info at import, replacing with fixed/default values or such.

bobakabob
03-13-2018, 04:22 PM
Autodesk keep updating FBX causing problems with other apps - in a recent interview Blender developer Ton airs frustrations. So Modeler’s interchange tools need to be updated more frequently.
I can’t import LW 2015 FBX or OBJ models into Maya without problems Eg weird black polys where everything worked fine in Maya 2017. My only workaround is to use this pipeline: LW - Zbrush - Maya and vice versa which is time consuming. Zbrush seems to accommodate both apps.
I was hoping LW 2018 would sort this but reading this, the signs are not good.

rustythe1
03-14-2018, 05:25 AM
Autodesk keep updating FBX causing problems with other apps - in a recent interview Blender developer Ton airs frustrations. So Modeler’s interchange tools need to be updated more frequently.
I can’t import LW 2015 FBX or OBJ models into Maya without problems Eg weird black polys where everything worked fine in Maya 2017. My only workaround is to use this pipeline: LW - Zbrush - Maya and vice versa which is time consuming. Zbrush seems to accommodate both apps.
I was hoping LW 2018 would sort this but reading this, the signs are not good.

well that's not strictly true that LW should fix it, because it did work and then it didn't when autodesk updated their end, if you look around forums like unreal etc Maya has a large number of issues with FBX in/out, where as when I'm working with any other app i never get issues because nearly all the other apps are still on 2014-16 too,

beverins
03-15-2018, 09:09 AM
I wish the Lightwave dev(s) would really thoroughly try out all their import/export options at the very least. And then state which version they tested against and which they require.

Though I have to say, Autodesk treats version compatibility like Apple and Adobe do. Even Motionbuilder sometimes can't load in its own native FBX file format because of incompatibility from Maya's flavor of FBX.

inakito
03-15-2018, 09:17 AM
Cameras from diff softwares may differ when exporting. When using Maya and Lightwave make sure the field of view matches...between one and the other. We use it so often and no troubles at all :)