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Thread: Omega object inside double-sided transparent object?

  1. #1
    3D Mac Maniac Scazzino's Avatar
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    Question Omega object inside double-sided transparent object?

    Has anyone been able to use an object with the omega shader inside (or behind) a transparent object that's double-sided?

    I'm getting shading artifacts on the omega surface as seen in this test. The same thing does not happen if I use Kappa or Sigma instead, but Kappa doesn't look as good and Sigma doesn't let me control the specular the way I like...

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    MikeS [LWProfile] 30+ Yrs of Award-winning Media DreamLight.com

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  2. #2
    3D Mac Maniac Scazzino's Avatar
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    The artifacts I'm talking about are the triangular facets that appear on the enclosed larynx, trachea and thyroid... turning off double-sided on the enclosing neck/torso object gets rid of them, but then I can't use the neck/torso to cast shadows onto the enclosed objects...

    Anyone have a workaround?
    MikeS [LWProfile] 30+ Yrs of Award-winning Media DreamLight.com

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  3. #3
    Ze Engineer connerh's Avatar
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    What all are your settings in Omega? Are you using single or multiple scattering, how many recursions, etc?

  4. #4
    3D Mac Maniac Scazzino's Avatar
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    It doesn't seem to matter. Here's the stripped down scene with the node map. I've tried changing every setting. Whenever I turn on the transparent torso object, it messes up the Omega surfaces of the cartilage and trachea inside. The outer transparency seems to mess up the handling of the double-sided polys in the Omega surfaces...

    I even tried replacing my cartilage surface with the greenish Omega surface posted from this thread, which had the same problems when inside the torso transparent surface...

    I'm going to run a test with real air polys instead of using double-sided with the spot-info/switch to see if that might work better.
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    Last edited by Scazzino; 07-25-2007 at 08:05 AM.
    MikeS [LWProfile] 30+ Yrs of Award-winning Media DreamLight.com

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  5. #5
    3D Mac Maniac Scazzino's Avatar
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    Using real air-polys rather than double-sided/switch didn't help either...

    MikeS [LWProfile] 30+ Yrs of Award-winning Media DreamLight.com

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  6. #6
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    Well I notice your not using a switch node, but are blending materials.
    I imagine this is part of the problem. Use a switch node instead of the material mixer node. My 2p.

  7. #7
    3D Mac Maniac Scazzino's Avatar
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    The problem was a bug that's been fixed...
    Here's the finished illustration and animation...
    Last edited by Scazzino; 10-05-2007 at 10:14 AM.
    MikeS [LWProfile] 30+ Yrs of Award-winning Media DreamLight.com

    Drag-and-drop-dead-easy™ ScreamerNet - DLI Constellation
    BOOK - Creating a 3D Animated CGI Short & 3D CGI Short Films & DLI Blog

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