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By simmsimaging
#356654
I'm trying to setup a render test for an animation to run on Rebus, but having issues with the output from Maxwell. Normally I render to mxi and ignore the Max save rollout, but for the farm I have to use that instead.

I am saving to .exr to try and get layered .exr files for my frames. That doesn't seem to work - I just get the channels separately and no layers (yes, I'm using ProExr to open them). Bigger issue though: the saved .exr files are coming out gamma corrected - so double gammad. The show the problem both in Photoshop and in Maxwell if I open it there. The gamma settings in Max are all turned off so I have no control over that.

Is this a bug, or how do I get the .exr output from Max/Maxwell without gamma?

Thanks /b
User avatar
By Bubbaloo
#356658
Rebus doesn't send you the finished MXI? Have you looked at The Ranch? They give you the MXI.

(Sorry I can't help with the EXR problem.)

Edit: On second thought, I'm not 100% sure the Ranch does that. It's been a few years since I've used it. Wow, I'm such a big help. :mrgreen:
User avatar
By tom
#356663
simmsimaging wrote:the saved .exr files are coming out gamma corrected - so double gammad. The show the problem both in Photoshop and in Maxwell if I open it there. The gamma settings in Max are all turned off so I have no control over that.
As a strict fact, neither EXR, nor HDR output receive gamma correction. The pixels are always linear. On the other hand, both PS and Maxwell has gamma corrected display. So when you load, they correct the display buffer itself, not the file.
User avatar
By simmsimaging
#356683
tom wrote:
simmsimaging wrote:the saved .exr files are coming out gamma corrected - so double gammad. The show the problem both in Photoshop and in Maxwell if I open it there. The gamma settings in Max are all turned off so I have no control over that.
As a strict fact, neither EXR, nor HDR output receive gamma correction. The pixels are always linear. On the other hand, both PS and Maxwell has gamma corrected display. So when you load, they correct the display buffer itself, not the file.
I'm not sure how it works internally, but I know that a linear workflow with .exr and, say, Vray or mental ray, would require that I set the output gamma from Max at 1.0 to avoid baking in gamma. You are correct that this isn't necessary for hdr - that doesn't seem to be affected.

Unfortunately the workflow for Maxwell requires turning off the Max gamma controls, so I don't have the option of setting the output gamma, and it looks like Max sets it at 2.2 by default.
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