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Problem: volumetric camera and transparent objects

zigraphixzigraphix Posts: 2,787
edited December 1969 in Daz Studio Discussion

I'm trying to make a volumetric camera using Shader Mixer, and the problem I'm running into is that transparent objects are being assigned the volumetric color of their distance from the camera, even though they are set to opacity = 0, which makes them visible. I want the volumetric part of the camera to ignore surfaces where Oi=0, but I've tried a number of experiments with hooking the Oi variable into different points of the Volumetric network, to no avail. Any suggestions?

depthcam_network.png
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volumetric_trans_bug.jpg
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Comments

  • zigraphixzigraphix Posts: 2,787
    edited June 2013

    This is with the Oi variable feeding into the Depth Cue brick. I was surprised that this helped (shouldn't the Depth Cue brick already be using this value?), but it's somewhat better, even though the sphere is still visible:

    depthcam_Oi.png
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    volumetric_trans_Oi_var.jpg
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    Post edited by zigraphix on
  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    If the sphere has "Visible in Render" turned off, or the eyeball is clicked next to the sphere in the scene tab, you can't see it at all:

    volumetric_trans_eyeclosed.jpg
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  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    I hoped that adding Ci and P to the network would help, but there was no improvement over Oi, either singly or both:

    depthcam_Oi_Ci_P.png
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    volumetric_trans_Oi_Ci_P.jpg
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  • zigraphixzigraphix Posts: 2,787
    edited June 2013

    Feeding Oi directly into the Volume root does not make the sphere invisible, but does eliminate the "fog" effect (leaving the depth cue color):

    depthcam_Oi_root.png
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    volumetric_trans_Oi_root.jpg
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    Post edited by zigraphix on
  • Richard HaseltineRichard Haseltine Posts: 102,291
    edited December 1969

    I'm not sure that this applies to non-surface settings, but try multiplying the opacity and colour together and connect that to the final colour.

  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    Using Simple Fog instead of Depth Cue works, but does not provide a color option. By multiplying the output Color by the color I want, I can get colored fog. I lose the ability to set the "End Distance" of the effect, though. So why doesn't the Depth Cue work this way?

    depthcam_simple_fog_color.png
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    volumetric_simple_fog_mult_color.jpg
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    volumetric_simple_fog.jpg
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  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    Richard Haseltine said:
    I'm not sure that this applies to non-surface settings, but try multiplying the opacity and colour together and connect that to the final colour.

    Is this what you meant?

    volumetric_simple_fog_mult_depthcue.jpg
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    depthcam_OixCi.png
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  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    Sorry, that last one I used "add" instead of "multiply." Here's what happens when I multiply in the same network as the previous post. It looks a lot like when I feed Oi directly into the Volumetric root.

    volumetric_simple_fog_OixCi_depthcue.jpg
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  • ReDaveReDave Posts: 815
    edited December 1969

    I had to look it up again, (http://www.daz3d.com/forums/discussion/20105/) :-S but you multiply opacity and colour and plug that as you did, then you also plug opacity in its own Surface/Volume/whatever input.

  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    ReDave said:
    I had to look it up again, (http://www.daz3d.com/forums/discussion/20105/) :-S but you multiply opacity and colour and plug that as you did, then you also plug opacity in its own Surface/Volume/whatever input.

    Ok... I tried that, but I can still see the transparent object. Does it matter that this is a Volume root, rather than Surface?

    I would also like to be able to get volumetric lights working with this camera (i.e. "god rays). Do I need to add a Caustic root for that?

    DepthCueCam2.jpg
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    DepthCueCam2.png
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  • ReDaveReDave Posts: 815
    edited December 1969

    Thinking back on this, I think it's as expected there: since it's volumetric, you'd have to apply the same material to the sphere for it to be completely ignored. As it is, you're asking the renderer to make a sort of empty bubble inside your fog/depth cue shader.

  • Richard HaseltineRichard Haseltine Posts: 102,291
    edited December 1969

    Isn't this a problem Age of Armour had with his Atmospheric Effects Cameras after the 4.5 update?

  • zigraphixzigraphix Posts: 2,787
    edited December 1969

    Richard Haseltine said:
    Isn't this a problem Age of Armour had with his Atmospheric Effects Cameras after the 4.5 update?

    It could be specific to 4.5... I haven't tried it on earlier versions. It is true that I get the same problem with Atmospheric Effects Cameras. Do you know if a bug has been filed?

  • Richard HaseltineRichard Haseltine Posts: 102,291
    edited December 1969

    zigraphix said:
    Richard Haseltine said:
    Isn't this a problem Age of Armour had with his Atmospheric Effects Cameras after the 4.5 update?

    It could be specific to 4.5... I haven't tried it on earlier versions. It is true that I get the same problem with Atmospheric Effects Cameras. Do you know if a bug has been filed?

    I don't. no.

  • PendraiaPendraia Posts: 3,598
    edited December 1969

    Richard Haseltine said:
    zigraphix said:
    Richard Haseltine said:
    Isn't this a problem Age of Armour had with his Atmospheric Effects Cameras after the 4.5 update?

    It could be specific to 4.5... I haven't tried it on earlier versions. It is true that I get the same problem with Atmospheric Effects Cameras. Do you know if a bug has been filed?

    I don't. no.Anyone know if this ever got fixed?

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