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Thread: Timeframe of Vray vs Mentalray implementation of glossy reflections / refractions

  1. #1
    Join Date
    Apr 2010
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    Default Timeframe of Vray vs Mentalray implementation of glossy reflections / refractions

    Hi and hello good people,

    I have a pretty weird but very serious question to pose: is there a way to determine when each renderer first implemented glossy reflections and / or refractions in their materials?

    Many thanks to whomever has the knowledge and the kindness to point one in the right direction.


  2. #2
    Join Date
    Dec 2005
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    mental ray shipped with the DGS material early but not sure when it was first shipped with mental ray. I was using it in 2002 but it was already in there.

    Custom mental ray solutions already had glossy reflections.

    Dunno about Vray, wasn't available for Maya.
    "Don't argue with an idiot, they will drag you down to their level and beat you over the head with experience."

  3. #3
    Join Date
    Dec 2004
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    Yes, the DGS and glossy reflections/refractions have been in mental ray a long time. In fact, there was also a path tracing material implementing glossy.
    Over the years, there were optimizations to glossy that took advantage of the evolving hardware resources capabilities.

    We used to teach this in training class over the years to give perspective.

    First optimization of glossy came with the understanding that if there were multiple glossy rays split out from the incoming ray, then when a ray path intersected many glossy materials, render time could go way up. So tracking that ray "splitting" number in accordance with ray depth could help speed up rendering hopefully with minimal visual effect.

    We taught how to write an appropriate glossy reflection/refraction shader to do this.

    The implementation of the glossy inside the Autodesk Maya Blinn shader for example, was then modified to speed it up.

    The mia_material shader was developed so that on first hit the glossy samples split the ray, but then after that, in the ray path depth, it would only send out 1 glossy ray for each of the next glossy surfaces intersected.

    The mila_material had a builtin function for reducing samples/splits based on a quality factor, that also took into account the roughness.
    Barton Gawboy

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