Canvas EXR's Alpha channel is weird with stranded hair

Hello, guys, the left is canvas rendering EXR, I bring it into Photoshop, put it over a solid background. the right is PNG. Why is the EXR alpha so weird?

I tried both enabling/disabling the filter/denoise, denoise alpha options, they all look the same. What's your thought? Do you guys use canvas a lot? I found it very complicated to use.

Post edited by onyxlee_9b3cce7f35 on


  • Wallace3DWallace3D Posts: 155
    edited May 11

    I use the Canvas Alpha Quiet a bit when Creating my own versions of the "Now Crowd Bilboards" that I have Purchase :D

    and I do not run into the issue. the Alpha.exr turns out very crisp and clear.


    I gues the Question is. How are you applying it?

    Alpha Test.png
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    Post edited by Wallace3D on
  • onyxlee_9b3cce7f35onyxlee_9b3cce7f35 Posts: 64
    edited May 11

    Thank you, Wallace3D, finally someone responded to me :-D

    I only bring exr file into Photoshop for post-production. First I have this exposure issue. All the tonemapping in the render settings can't reduce the exposure of exr. You have to manually create an exposure layer and change the exposure value to -13 to -14, to get the result close to PNG rendering. Then this alpha issue also appears in the exr, when I overlay it on top of a solid layer in Photoshop. It seems like only stranded hair has this issue. Other polygon hairs with transparency maps (image 2) don't have this issue. Any thought?

    Thanks again.

    Post edited by onyxlee_9b3cce7f35 on
  • Wallace3DWallace3D Posts: 155

    I think I followed

    So I opened up the exr

    and this is the result

    Normally I would go into Image -> adjustments HDR Toning but it takes away the transparancy :-/

    try Grouping the Layer and the adjustment on top of your background

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  • onyxlee_9b3cce7f35onyxlee_9b3cce7f35 Posts: 64
    edited May 12

    Thanks again, Wallace. Your way of putting those layers in a group folder is the same thing as this "masked layer". I tried your approach and used gamma 1.25 in my setting, it doesn't solve the problem.

    So, did you use strand hair or regular polygon hair in your example? My regular hair also renders with perfect alpha. Only strand hair gives me this result. Maybe it's in strand hair shader???

    Also, may I ask you why you give the gamma 1.25? This value will make my image look flat. the default value of 1 gives me the same result as PNG render.


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    Post edited by onyxlee_9b3cce7f35 on
  • Wallace3DWallace3D Posts: 155

    1.25 was for my specific render to get the lighting good. otherwise the character had to bright of highlights.

    So now it is making sence as to why you are getting the unclean look on the hair

    Standed hair is not iRay friendly and has to fake it to make it.  it is not as noticable on an 8 bit png but since you are rendering to a 32bit you are seeing all the artifacts from the attempt to make the strands look like hair.

  • Thanks again for your reply. Where do you set up the 1.25 gamma in the daz studio render settings?

    Some stranded hair looks totally fine in EXR format, but this one is just weird. I am looking closely into the material/shader and see if I can find anything.

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