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  • alpha in render element channel (EXR)

    Is there a way to not have the alpha component passed into the render element channels when exporting to EXR?

    mme1_no-alpha.png is saved from the VBF as png but with no alpha, seperate the RGB channel is PS and you have full masks of you selected elements.

    mme1_exr-alpa.png is saved from PS as it comes in from proEXR with the alpha component included in the render element which isn't always wanted (I'm not sure when it would be needed either?), therefore requiring additional steps to create a full mask.

    Should there be a ignore alpha tick box in the render element section? (Should I had this to the wish list?)
    I should also say that I would prefer to have the RGBA remain as is (with the alpha applied) just not the render elements.
    Attached Files
    Simon

    .... . .-.. .--. .-.-.- .--. .-.. . .- ... . ... . -. -.. -.-. .... --- -.-. --- .-.. .- - .
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    Max2017.1 | Vray 3.70.01| win11
    ASUS Z790PLUS | i9 13900K | 64Gb RAM | Geforce GTX4070Ti

  • #2
    Number 2 is just wrong according to EXR specs (and common sense i guess ?). The alpha should never be automatically premult any color channel.
    This is rather how PS (and seemingly proEXR ?) handles the EXR, not how it is saved

    Regards,
    Thorsten

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    • #3
      yes, as thorsten says, that's how bad PS handles alphas.. and it's even more depressing if you think that AE import them correctly. I mean, why one adobe application can, and the other can't?

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      • #4
        Click image for larger version

Name:	AE-proEXR_Comp.jpg
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Size:	92.0 KB
ID:	843981@rivoli - I just tried it in AE and it is the same as PS, as in if I change the background colour of the composition my mme elements show the background where the alpha was...(AE_CS3)

        @instinct I know it's wrong, but it is possible to get this same result from the VBF by saving the MME as a png with the alpha checkbox ticked. This is what lead me to think it was max/vray out-putting incorrectly, as like you said, the alpha should never be automatically premult to a render element, but it does!!

        I don't know if proEXR is doing it wrong or it is just doing it the same way it does with RGBA info, since that is what a mme element is...just another set of RGB channels, why shouldn't it (being devils advocate) have the Alpha applied? Should there be something that indicates it is different?
        Simon

        .... . .-.. .--. .-.-.- .--. .-.. . .- ... . ... . -. -.. -.-. .... --- -.-. --- .-.. .- - .
        I need a new signature
        --
        Max2017.1 | Vray 3.70.01| win11
        ASUS Z790PLUS | i9 13900K | 64Gb RAM | Geforce GTX4070Ti

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        • #5
          Originally posted by ior=0 View Post
          [ATTACH=CONFIG]6353[/ATTACH]@rivoli - I just tried it in AE and it is the same as PS, as in if I change the background colour of the composition my mme elements show the background where the alpha was...(AE_CS3)
          did you change the way AE interprets the image? doesn't it work if you tell it to ignore the alpha channel?

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          • #6
            The PNG variant is a similar issue and interpreted just as wrongly as EXR i guess (tho am not an expert with PNG heh).
            There is a PLUGIN by Adobe now to fix it (only for CS5 tho)...Writing a plugin should be the weirdest way to fix a damn
            bug i ever saw....

            http://kb2.adobe.com/cps/883/cpsid_88310.html

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