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Cross Platform Render Farm (gamma shifting)

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Does anyone use a cross platform render farm successfully with After Effects/Maya/C4D/Nuke? Primarily wondering about After Effects rendering frames from both OS X and Windows nodes. From some initial tests it's looking like certain codecs Prores, PJPEG, MJPEG, etc. will have shifted gamma.

 

If the source footage is one of those formats in AE and it gets rendered in a mixed farm, when I bring the rendered frames back in AE on a Mac workstation, turn the render to 'difference' blend mode, the frames that Macs render were zero (as they should be) in the info panel, but on the PC frames range from 1-4 for some codecs and up to 40 difference on MJPEG. The opposite is true when you bring it into AE on PC. When you prerender the offending codec to Animation, Avid, or image sequences like TGA locally first then render it though there is no shifting on mixed machines.

 

I've asked around and it seems like rendering all on one platform is the way to go but thought I'd put it out there if people have come across any other solutions. Supposedly QT on Windows is sketchy. Similarly wondering if Maya/C4D has any cross platform issues.

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Since Apple switched to Intel processors i haven't heard of any platform related problems with CINEMA 4D. Before the switch the different floatingpoint calculation precision could result in rendering differences.

There were some occasions where users installed different versions of Quicktime on different clients and image/video files that relied on QT to load were interpreted differently, but if you don't rely on that there should be no problem at all.

 

Cheers

Björn

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I see a few fundamental problems with the description of what your tests are.

 

PCs cannot write ProRes files, so I don't know how you are achieving that test at all.

 

You are also referencing video codecs, which is a bit odd.... Stick with image sequences, TGA / PNG / TIFF / OpenEXR and you shouldn't have these problems.

Edited by AromaKat

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I see a few fundamental problems with the description of what your tests are.

 

PCs cannot write ProRes files, so I don't know how you are achieving that test at all.

 

You are also referencing video codecs, which is a bit odd.... Stick with image sequences, TGA / PNG / TIFF / OpenEXR and you shouldn't have these problems.

I'm not writing to prores the problem is always with source footage in AE. (Decoding not encoding.)

 

To convert every QT from clients and stock library/footage to image sequences would take forever and my guess is most people would end up forgetting anyway so don't think prerendering is a practical solution. We may need to accept that QT is just different on the two platforms but wanted to see if others have gotten around this somehow.

 

 

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Ah, I see what your saying now... Your source footage is ProRes...

 

There shouldn't be a need to convert source footage into image sequences. I haven't ever seen a problem like that.

 

I guess make sure all of your quicktime installations are all up to date.

 

The problem definitely can't be blamed on Quicktime, but maybe it can on specific codecs. I mainly work with DNxHD (Avid's ProRes) source files and don't have these issues.

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