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    Reflection Falloff

    Scheduled Pinned Locked Moved V-Ray
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    • andybotA Offline
      andybot
      last edited by

      The first image is definitely just a blurry reflection. Like oganocali says - using .85 for glossiness would work fine. The second one has an accentuated falloff without the blurriness. I wonder if it's just a lower IOR value, like 1.2

      http://charlottesvillearchitecturalrendering.com/

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      • oganocaliO Offline
        oganocali
        last edited by

        I have trouble replication the graduated fall off effect in picture 2. In theory fresnel reflection should do it for small ior. Somehow vray fresnel reflection falls off too abruptly as in total internal reflection as seen (ior 1.2). I am pretty sure I have the correct surface orientation but... Apparently vray is doing some kind of approximation for this reflection. I am pretty sure the physics require a smooth graduated fall off. Strange.
        fresnelonly.jpg

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        • andybotA Offline
          andybot
          last edited by

          do you have a filter color for the reflection layer? I see that effect sometimes if the filter color is too dark. Set it at white and see if you still get that effect.

          http://charlottesvillearchitecturalrendering.com/

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          • thomthomT Offline
            thomthom
            last edited by

            oganocali: remember that you also need to make the reflection blurry in order to reproduce the original image posted.

            Thomas Thomassen — SketchUp Monkey & Coding addict
            List of my plugins and link to the CookieWare fund

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            • oganocaliO Offline
              oganocali
              last edited by

              @andybot: I don't have a filter.
              @thomthom: I was trying to reproduce the effect in the 2nd picture. I feel that one does not have blurriness.

              Well, just before the reflection drops to zero there is a small graduated region I think, may be I am imagining it.
              There seems to be something I am missing.

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              • V Offline
                valerostudio
                last edited by

                Wow, I must be dense! I dont know why I didn't realize Fresnel did this. I have used it a million times. What what you use if you wanted it to fade off in a shorter distance? Would you just change the IOR value?

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                • oganocaliO Offline
                  oganocali
                  last edited by

                  @valerostudio: Smaller value of IOR should make the reflection fade off earlier as I understand , but somehow in vray the reflection dies off more completely and abruptly than I expect.

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                  • thomthomT Offline
                    thomthom
                    last edited by

                    I did use falloff once for such an effect in 3dsmax. Found it, then, easier to control in that situation than fresnel.

                    Thomas Thomassen — SketchUp Monkey & Coding addict
                    List of my plugins and link to the CookieWare fund

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                    • V Offline
                      valerostudio
                      last edited by

                      But we all agree that fresnel is the best solution for realistic reflections? Would you ever just use a color value to control the reflection amount and not use fresnel?

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                      • thomthomT Offline
                        thomthom
                        last edited by

                        @valerostudio said:

                        But we all agree that fresnel is the best solution for realistic reflections?

                        Yes

                        Thomas Thomassen — SketchUp Monkey & Coding addict
                        List of my plugins and link to the CookieWare fund

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