Announcement

Collapse
No announcement yet.

iridescence

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

  • iridescence

    Hello, noob here, how do we create iridescent shaders in vray for houdini?
    somethign like this...
    thanks
    Attached Files
    x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

  • #2
    Hi anthony_kyriazis,

    There's a very easy and cheap way to achieve this by mapping a falloff to a gradient map that is then used as your reflection. You can map any color to that gradiend, and get the colors you need depending of the angle of view (falloff mapped to fresnel or towards/away).

    Click image for larger version  Name:	iridiscence.JPG Views:	0 Size:	174.6 KB ID:	1092711

    Best,
    David.
    Last edited by david.anastacio; 19-11-2020, 04:32 AM.
    David Anastácio // Accenture Song - VFX
    https://www.accenture.com/us-en/serv...visual-effects

    Comment


    • #3
      Also the Vray pluginnodetex thin film tex will work well. Here it's a coat on a blend material.
      Attached Files
      https://www.behance.net/bartgelin

      Comment


      • #4
        Originally posted by fixeighted View Post
        Also the Vray pluginnodetex thin film tex will work well. Here it's a coat on a blend material.
        Hi, where do i find that thin film? i have downloaded this https://docs.chaosgroup.com/display/...in+Film+Shader but cannot get it to work...
        x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

        Comment


        • #5
          thank you @david.anastacio giving it a try...
          x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

          Comment


          • #6
            It is in the list of all other maps, called vray pluginnodetex. Use it in the reflection colour slot for the coat material. Set the blend to 'additive shellac mode.
            Enable anisotropy of e.g. 0.9 or whatever looks good and make it somewhat glossy..0.5 to .9 seems good.
            If you then vary the glossiness of the base material then you can get anythng from your example to an e.g. blurry car paint iridescent paint/pearlescent effect.
            I don't use Houdini but these settings I imagine will translate.
            https://www.behance.net/bartgelin

            Comment


            • #7
              Originally posted by fixeighted View Post
              Also the Vray pluginnodetex thin film tex will work well. Here it's a coat on a blend material.
              That OSL texture was crashing some weeks ago last we tried it. But yes, this should be a more accurate result.
              But the one I showed can also be easily used as a coat on a blend material too.

              Best
              David.
              David Anastácio // Accenture Song - VFX
              https://www.accenture.com/us-en/serv...visual-effects

              Comment


              • #8
                Hmm, no crashes here using it over long periods to test other scenarios...but then that's with Max, so maybe it's something not playing well with Houdini

                Your version sure does work just fine, so options
                https://www.behance.net/bartgelin

                Comment


                • #9
                  Originally posted by fixeighted View Post
                  Hmm, no crashes here using it over long periods to test other scenarios...but then that's with Max, so maybe it's something not playing well with Houdini

                  Your version sure does work just fine, so options
                  This was Houdini issue only, I found a recent post of the bug:
                  https://forums.chaosgroup.com/forum/...2213-osl-error

                  But nothing in that post indicates that the issue has been fixed yet, and I haven't tried it with the latest nightlies.

                  Best,
                  David.
                  David Anastácio // Accenture Song - VFX
                  https://www.accenture.com/us-en/serv...visual-effects

                  Comment


                  • #10
                    Ah ok, that's a shame.
                    https://www.behance.net/bartgelin

                    Comment


                    • #11
                      not quite the result i was after.. but enjoyed it .. thank you all.. still can;t get that result described.
                      Attached Files
                      x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

                      Comment


                      • #12
                        Hmm...it's hard to know what you are after, as your first example is very different to this one.
                        Can you explain more what you want to see, based on this much more abstract form?
                        Maybe just photoshop it to show the ideal effect...
                        https://www.behance.net/bartgelin

                        Comment


                        • #13
                          Originally posted by anthony_kyriazis View Post
                          not quite the result i was after.. but enjoyed it .. thank you all.. still can;t get that result described.
                          "Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfly wings and seashell nacre, as well as certain minerals."

                          "as the angle of view ... changes" = Fresnel effect (Falloff map with Fresnel mode)
                          "gradually change color" = Gradient Ramp.

                          So with this two parameters we should be able to emulate our iridescence effect in any renderer. This is a bit simplification of course, things can get a bit more complicated that's why you can find things like the thin film shader that account for more nuances of the effect. But in a general way, this should suffice.

                          The technique applied on a similar mesh used on a metal shader:
                          Click image for larger version  Name:	iridescence.jpg Views:	0 Size:	486.7 KB ID:	1092995

                          vs the example from your post in the Houdini artists Facebook group (discount lighting and shape):
                          Click image for larger version  Name:	example.jpg Views:	0 Size:	301.0 KB ID:	1092997

                          The same technique in a sphere (soap), you can even add the common distortions of soap with noise maps:
                          Click image for larger version  Name:	soap.jpg Views:	0 Size:	418.4 KB ID:	1092996

                          P.S: This was 15 minutes of my time, it's normal that my result is not super accurate to your example image. It's just a friendly example scenario.

                          Best,
                          David.
                          Last edited by david.anastacio; 20-11-2020, 05:26 PM.
                          David Anastácio // Accenture Song - VFX
                          https://www.accenture.com/us-en/serv...visual-effects

                          Comment


                          • #14
                            david.anastacio thank you SOOOOOOOO much!!! you super star!
                            x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

                            Comment


                            • #15
                              @david.anastacio I got it to work, but only in CPU mode... as son as i try with GPU it does wired stuff.
                              x570, 5950x, 96gb Ram, Gigabyte Turbo RTX 3090, Asus Turbo RTX 3090, 2x Samsung 970 Evo SSD 1.0TB M.2 NVMe , 1000 corsair + 750 corsair PSU's. houdini 18.5 . vray 5.1

                              Comment

                              Working...
                              X