Reality is 6 Years Old and I Have a Question

Is there any real difference in the photoreal quality of shaders and light between Lux and Iray?

Comments

  • thd777thd777 Posts: 945

    In my opnion, as long as each is set up properly and uses native materials, no. There is no difference in the photoreal quality that can be achieved.

    Ciao

    TD

  • Define "native".

  • mtl1mtl1 Posts: 1,508

    Reality doesn't rely on convergence, so the "type" of image you get from Reality will be much different. The main advantage of Reality is that scenes obey realistic lighting schemas. At the same time, the main disadvantage is that Reality, like other physics-based renderers, obeys realistic lighting schemas, so indirect lighting will always be an issue.

  • Nyghtfall3DNyghtfall3D Posts: 813
    edited August 2016
    mtl1 said:

    Reality doesn't rely on convergence, so the "type" of image you get from Reality will be much different. The main advantage of Reality is that scenes obey realistic lighting schemas.

    What's the difference between the two methods?  I know how they work in terms of rendering, I'm asking what the under-the-hood difference is that results in the "type" of image each one produces - the technology behind them.

    Post edited by Nyghtfall3D on
  • mtl1mtl1 Posts: 1,508

    The simplest explanation I can give is that Iray, another physically-based renderer, works by convergence -- that is, when the "solution" to the image no longer changes -- whereas Reality renders never truly end as it is continuously generating photon counts over time.

    One analogy for Reality is the simulation of a double-slit interference pattern with randomly generated photons...

  • thd777thd777 Posts: 945
    edited August 2016
    Nyghtfall said:

    Define "native".

    Native means materials and shaders designed and set up for the render engine. Not auto converted from another render engine.

    Reality doesn't render at all. It produces a text file that is read by Lux Render.

    Both Lux Render and Iray require the collection of enough samples/rays/data to produce a noise free image = convergence. The difference is that Iray uses specific parameters to define when an image is "done". Whereas Lux Render by default lets the user decide when it is enough (even though you can also set parameters to define what the target is).

    Both Iray and Lux Render can use a photo real mode that approximates real light behavior including indirect light, reflection, refraction, caustics, etc. Iray allows you to choose a subset of features if you want, Luxrender via Reality is pretty much always doing everything.

    You will have a hard time to get the exact same look because there are too many variables, but from a purely "This looks real" standpoint, there is no significant difference.

    LuxRender might have a small advantage in situations where the mixed wavelengths nature of light matters (refraction through a prism for example) but in most standard situations this is not significant.

    Ciao

    TD

    Post edited by thd777 on
  • thd777thd777 Posts: 945
    edited August 2016
    mtl1 said:

    The simplest explanation I can give is that Iray, another physically-based renderer, works by convergence -- that is, when the "solution" to the image no longer changes -- whereas Reality renders never truly end as it is continuously generating photon counts over time.

    One analogy for Reality is the simulation of a double-slit interference pattern with randomly generated photons...

    Sorry but that is just semantics. If you set Iray to 100% convergence and give infinite time and iterations it won't stop either. Just like LuxRender which is by default stopped when the user decides that it has "converged" or the set limit is reached.

    Edit to add: You can set up LuxRender to stop automatically based on image convergence. This is not accessbible via Reality as far as I know but you can read about it for example here for LuxBlend: http://www.luxrender.net/forum/viewtopic.php?f=11&t=10797

    TD

    Post edited by thd777 on
  • thd777 said:

    Native means materials and shaders designed and set up for the render engine. Not auto converted from another render engine.

    Understood.

    thd777 said:

    Reality doesn't render at all. It produces a text file that is read by Lux Render.

    I know. I've used both, and currently use Iray.

    thd777 said:

    ...from a purely "This looks real" standpoint, there is no significant difference.

    Thank you.

  • thd777thd777 Posts: 945

    Yes, I have used both, too. They are both excellent render engines and capable of a very high degree of realism. I am currently using Iray, mostly because it plays better with my GPUs. I have used Luxrender mostly via the Luxus interface and to a lesser degree via Reality. Mostly because I do not like the philosophy of the interface design in Reality, but that is of course a personal preference.

    Ciao

    TD

  • mindsongmindsong Posts: 1,753

    good question, and to the respondants, great answers. Thanks for taking the time to 'humanize' the complexity under the hood. Appreciated.

     

    --ms

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