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Vlado's post - Universal V-Ray settings (well, almost)

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  • Vlado's post - Universal V-Ray settings (well, almost)

    Until we work out access to the Chaos group V-Ray forum I figured I copy the first post of a recent thread started by Vlado. The thread is here for those who can access it.

    http://www.chaosgroup.com/forum/phpB...ic.php?t=14747

    Best regards,

    Corey

    Originally posted by vlado
    I've been asked many times what are "good" V-Ray settings. Of course, there is no universal answer and it depends on the desired render speed and quality, but here is a set of settings that I have found to work very well for still images in many situations. Please note that these settings are not optimal, in the sense that with enough tweaking, you can probably get similar quality with faster render times. The beauty of these settings though, is that they require almost no tweaking and you are guaranteed to get a nice result in the end.

    Provided that you start with a default V-Ray renderer:
    (*) In the Image sampler rollout, switch to "Adaptive QMC".
    (*) Set the "Max. subdivs" to 100 (one hundred). Leave the "Min. subdivs" to 1.
    (*) Set the primary GI engine to QMC GI. Do not change the subdivs.
    (*) Set the secondary GI engine to Light cache.
    (*) Set the light cache interpolation samples to 5.
    (*) Set the QMC Sampler "Adaptive amount" to 1.0.
    (*) Un-check the "Clamp output" option in the Color mapping rollout.[*] Typically you will need to adjust the Noise threshold as the default produces too much noise. A good value is 0.001.
    (*) You are done.

    To control render quality vs render time:
    (*) Adjust the QMC Noise threshold. Lower values reduce noise, but increase render times.
    (*) Adjust the light cache subdivs. This is scene dependent, but usually values from 1000 to 5000 are enough for most scenes. You can also adjust other light cache parameters as necessary.
    (*) Turn on or off reflective/refractive GI caustics as needed.
    (*) Optionally turn on the "Use light cache for glossy rays" option to speed up glossy reflections.
    (*) You may want to adjust the render region (bucket) size for faster feed-back.

    Notes:
    (*) Leave all subdivs anywhere at their default values. They won't have any effect anyways - the 100 AA subdivs will almost certainly override everything else.
    (*) For builds of V-Ray before 1.49.30, DO NOT use color mapping other than Linear. Otherwise, you risk to get an incorrect result in the end. If necessary, apply color correction in post. You can change the dark/bright multipliers, provided that you leave both at the same value.
    (*) Avoid using sharpening AA filters. They can make the noise more apparent.

    Advantages of these settings:
    (*) Very little parameters for controlling render quality.
    (*) Work for a very large number of scenes.
    (*) Typically produce high-quality results.

    Disadvantages of these settings:
    (*) May be slow to render. With tweaking, you may get faster results.

    How it works:
    The high AA subdivs essentially causes all the sampling to be performed by the image sampler. It will take as many samples per pixel as required to achieve the specified noise threshold. In many ways, this is similar to PPT, but is done on a per-bucket basis and the number of samples is adaptive.

    Examples:
    Here are some examples which have all been rendered with these settings, with minor differences (GI caustics on or off) and Noise threshold of about 0.001:
    http://www.spot3d.com/vray/images/stuff/univ_settings/
    As you can see this method can also render GI caustics quite well, although they may take quite some time.

    Best regards,
    Vlado
    Best regards,

    Corey Rubadue
    Director

    Chaos Group

  • #2
    Vlado's post - Universal V-Ray settings (well, almost)

    hello Corey,

    thank you for the info, i find this highly intereresting!
    I am just testing these (very exotic) settings and up to a certain degree it works quite nice, however in order to reduce the noise, i tried to lower the noise treshold under the qmc settings (as suggested in vlados text) but in the dialog box 0.001 is the lowest value i could enter... is it just me or can you repead this?

    best regards

    Andy

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    • #3
      Vlado's post - Universal V-Ray settings (well, almost)

      Awesome !
      Thank you Corey

      Now if we were able to save presets (as outlined here http://www.asgvis.com/phpBB2/viewtopic.php?t=242) then we could make one and use it all the time ...


      Soooo, sweet !!!

      Comment


      • #4
        Vlado's post - Universal V-Ray settings (well, almost)

        This is what's cool about having a render engine that's cross platform - you learn how to use it in one environment, you know how to use it in any environment that its compatible in. This is one of V-Ray's biggest strengths.


        /BlueShift

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        • #5
          Vlado's post - Universal V-Ray settings (well, almost)

          Corey, thank you for repost the thread. Very interesting.

          -Micha
          www.simulacrum.de - visualization for designer and architects

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          • #6
            Vlado's post - Universal V-Ray settings (well, almost)

            I can repeat the noise threshold issue..thxs for the pointer.

            Preset's are coming...promise.

            Best regards,

            Corey
            Best regards,

            Corey Rubadue
            Director

            Chaos Group

            Comment


            • #7
              Vlado's post - Universal V-Ray settings (well, almost)

              ... I wonder me a little about the secondary LC. In my test I have got the feeling, it dosn't seems to converge like in ppt mode. So, I have not seen difference between a sec LC 1000 and 5000. The noise is changing, but stay at the same level. Is it a bug here?

              So, I have decided me to use the QMC GI for both prim and sec.

              EDIT: ... without the clamp we have one problem, the bad alising effcet at edges with a bright background. For example important for arch viz in a HDRI environment - here the roof contour.
              www.simulacrum.de - visualization for designer and architects

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              • #8
                Vlado's post - Universal V-Ray settings (well, almost)

                ... in "exponential" the anitaliasing is no problem.
                www.simulacrum.de - visualization for designer and architects

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                • #9
                  Vlado's post - Universal V-Ray settings (well, almost)

                  Did you find some other kind of settings that has a good ratio quality vs time ?
                  I found that Vlado recommended settings are still reeeealllly long. Even if it's pretty effective, neat result.
                  Freelance Industrial Designer - Rhino3d v4 - Vray for Rhino

                  Comment


                  • #10
                    Vlado's post - Universal V-Ray settings (well, almost)

                    I use the universal method very often, but if I need more speed, than I jump from QMC GI to IM GI with the settings:
                    -3 / -1 / 256 samples / color threshold 0.2
                    Good for many situations. Additional I use the full adaptive QMC sampling. I have done the GI jump at my last gallery images (22)...(24). My test has shown me to long rendertimes and so I have used the IM mode.

                    Important for a good speed is to get a feeling for the usage of the right light type. Emitters are good for LC-QMC, but if the emitters are small and send light to a big area, recangular lights are better, because small emitters cause more noise or longer rendertime. But to much arealights can slow down a rendering too. For example did you see the small boxes in image ( 8 ) and (9)? In a previous version of the scene I have used approx. 30 boxes with arealights - extrem slow. Than I have used emitters - each box one emitter - much faster (factor 10). The emitters are small here, but send light to a small area only, so it is no problem.

                    Important is to understand, that is is easy to sample emitters, but if they are not so small compared to the lit area. If the lit area is much bigger as the emitter, than the sample calculation is difficult. Here it is better to use light instead emitters. If a scene needs many lights, than it is better to use emitters than lights. Because emitters in the scene are sampled per random calcualtion. Lights are sampled all from each point in the scene.

                    Maybe I'm wrong with something here, but this helps me to keep the speed.

                    -Micha
                    www.simulacrum.de - visualization for designer and architects

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                    • #11
                      Vlado's post - Universal V-Ray settings (well, almost)

                      excellent micha.
                      it's a good resume for all of us.
                      Jp
                      Freelance Industrial Designer - Rhino3d v4 - Vray for Rhino

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                      • #12
                        Vlado's post - Universal V-Ray settings (well, almost)

                        hey
                        is it possibel to change som settings under the query, for ex. lights ect?

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                        • #13
                          Vlado's post - Universal V-Ray settings (well, almost)

                          irradiance map works best for me

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                          • #14
                            Re: Vlado's post - Universal V-Ray settings (well, almost)

                            Shall i put GI on or off with the Vlado settings ? Which is better ?

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                            • #15
                              Re: Vlado's post - Universal V-Ray settings (well, almost)

                              It's a GI based method, so you must enable GI.
                              www.simulacrum.de - visualization for designer and architects

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