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    Reflection Falloff

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    • oganocaliO Offline
      oganocali
      last edited by

      Indeed fresnel map for reflective layer reduces reflection strength for more obtuse rays. The increase in fuzziness can be obtained by reducing the glossiness of the reflective layer. This is obtained with glossiness 0.85 and fresnel map with index 5. This does not fit your first case exactly (this one somehow has a smoother feel) but you may find it useful.

      good luck
      material.jpg

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      • N Offline
        nomeradona
        last edited by

        oganocoli was right just use fresnel refelction and blurrying it

        visit my blog: http://www.nomeradona.blogspot.com

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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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