Announcement

Collapse
No announcement yet.

blotchy render with irmap

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • blotchy render with irmap

    Yes, I have been using IRmap (with LC for primary) for a long time now, and usually had good results. I am having a few problems with blotchiness with this scene though. If I use QMC/LC it looks better, but I need the settings pretty high to get rid of fine noise.
    Here's a screen grab of a render in progress:

    And my settings are as follows:
    Vray sunlight/skylight plus about 20 vraylights for the ceiling lights closer to the core of the building. The glowing Vraylightmtl I am using for the actual lights is set not to generate GI
    Image Sampler: Adaptive DMC, min=1, max=16, Clr thresh=0.02
    IR: Irmap=medium settings with 80 Subdivs and 20 Interpolation
    LC: 1000 default settings (light cache NOT used for glossy rays)
    DMC Sampler: Adaptive amount 1.0, Noise thresh=0.01, Min samples=5
    (I think it may be these last settings that need work)

    Its amazing how much I am still learning about Vray, and I've been using it for years now. Most of my work in the past has been with exterior shots so I think you can get away with knowing less about global illumination - stick a vraysun and vraysky in there and its great. Interiors call for a much deeper knowledge of vray and the recent online tutorial by cpnichols has been very useful indeed, but it creates pretty high rendertimes when using brute force/LC. I really want to get it working with Irmaps/LC but am often having these blotchy problems.
    Kind Regards,
    Richard Birket
    ----------------------------------->
    http://www.blinkimage.com

    ----------------------------------->

  • #2
    as lele has said try setting your irmap samples to something like -6 -1.
    ____________________________________

    "Sometimes life leaves a hundred dollar bill on your dresser, and you don't realize until later that it's because it fu**ed you."

    Comment


    • #3
      Does setting the irr to -6/-1 help at all?

      Comment


      • #4
        hrm.. too slow... haven't had any coffee yet. *chuckle*

        Comment


        • #5
          I have cahnged my DMC Sampler settings. I had adaptive set to 1.0 but I have put it to 085 now with Noise at 0.005 and min samples to 8. It seems a lot better - I think they were at the values I had used for brute force. I will give the -6/-1 a go as well.
          Kind Regards,
          Richard Birket
          ----------------------------------->
          http://www.blinkimage.com

          ----------------------------------->

          Comment


          • #6
            I've also put some vraydirt on the plaster walls which helps bring out a bit more detail which is lost with using Irmap for the GI - it seems to work quite well - is this common practice?
            Kind Regards,
            Richard Birket
            ----------------------------------->
            http://www.blinkimage.com

            ----------------------------------->

            Comment


            • #7
              Hi, tricky.. and hi all Vrayers !!
              did you tried detail enhancement, instead of dirt ? it works well in many cases to catch thin gemetry GI...
              of course it slows down a little, but you can try to check it with IM -6 -2 instead of -6-1. you can also raise up a little interpolation samples.
              try as start guide hsph * global multiplier * DE multiplier = 16
              and reach 32 for final prod render. rocks for me, i often use it.
              nice interior, dude !
              Jérôme Prévost.
              SolidRocks, the V-Ray Wizard.
              http://solidrocks.subburb.com

              Comment


              • #8
                Congrats on your first post dude!
                (Sorry - went into Bill and Ted mode for a minute!)
                Kind Regards,
                Richard Birket
                ----------------------------------->
                http://www.blinkimage.com

                ----------------------------------->

                Comment


                • #9
                  thanks for your welcome.. i'm so happy to have my little place here..
                  hope my first post tips have an interest for you
                  Jérôme Prévost.
                  SolidRocks, the V-Ray Wizard.
                  http://solidrocks.subburb.com

                  Comment


                  • #10
                    Hi,

                    I think setting the adaptive amount to a greater value than .85 can lead to a lot of blotches. I had this often in the past. Sometimes you can get as high as you want with the ir settings - the blotchiness won't go away!

                    On the other side setting it to 1.0 can speed up your renderings a lot without loosing quality. May be there is a trick to avoid this. The only thing i know to avoid it, is to render your ir with 0.85 and change it to 1.0 for the rest of the rendering...

                    I post this in another thread, in hope to get response from all the vray-gurus. Would be great to get some tips on this.Any ideas???

                    As far as i know, this just happen with ir in single mode. If you can use multiframe incremental you're a lucky guy!

                    best regards

                    stefan
                    _____________________

                    Stefan Kurz

                    www.StefanKurz3d.de
                    _____________________

                    Comment

                    Working...
                    X