Shaders that change based on surface angle to camera?

agent unawaresagent unawares Posts: 3,513
edited December 1969 in The Commons

I'm curious whether it's possible to build [hopefully using the Shader Mixer in DS] a shader that will behave differently depending whether the surface being rendered is head on to the camera, or angled away. Is there a node that would make it possible to do this?

Comments

  • TheKDTheKD Posts: 2,691
    edited December 1969

    Well, under functions there is a fresnel node, so it should be possible. How fresnel works in daz, or if it works well at all, I cannot tell you lol. I am learning about fresnel in blender cycles now myself.

  • agent unawaresagent unawares Posts: 3,513
    edited December 1969

    Whoa, I never thought of trying that - it would be much simpler than anything I was going to attempt. There might be problems depending on how it's implemented, but that sounds like exactly what I need. Thanks.

  • PendraiaPendraia Posts: 3,598
    edited December 1969

    Whoa, I never thought of trying that - it would be much simpler than anything I was going to attempt. There might be problems depending on how it's implemented, but that sounds like exactly what I need. Thanks.

    Sunshine girl and I worked on a shader that would imitate the effects of iridescent silk that changes colour according to where the light is. The network we started with can be found in the DAZ wip forum in the forum archives. Sorry I don't have a link any more. We managed to come up with a network the seemed to give reasonable results.

  • Mr Gneiss GuyMr Gneiss Guy Posts: 462
    edited December 1969

    Was this the thread you mean? I don't know how useful it will be, since the images of the networks aren't there.

    http://forumarchive.daz3d.com/viewtopic.php?t=155932&postdays=0&postorder=asc&start=0

  • agent unawaresagent unawares Posts: 3,513
    edited December 1969

    Unfortunately there's that problem with almost all the old shader building threads.

  • FirstBastionFirstBastion Posts: 7,760
    edited February 2013

    There is a workaround to see the posted images in archive threads, but its a bit time consuming. If you add the postimages/origimage code address into the forumarchive URL the individual network screen captures will be visible.

    example:

    http://forumarchive.daz3d.com/postimages/origimage_1_2710719.jpg

    oldarchiveforum.jpg
    1280 x 1024 - 346K
    Post edited by FirstBastion on
  • Richard HaseltineRichard Haseltine Posts: 100,747
    edited December 1969

    To see the images, copy the postimages/origimage_1_2710719.jpg bit from the HTML and paste it after forumarchive.daz3d.com/ to get the full url for the image in your address bar - forumarchive.daz3d.com/postimages/origimage_1_2710719.jpg

  • agent unawaresagent unawares Posts: 3,513
    edited December 1969

    Wow, that's crazy useful, thanks.

  • wancowwancow Posts: 2,708
    edited December 1969

    Is it possible to alter the equation associated with the 3Delight Fresnel Shader?

  • wancowwancow Posts: 2,708
    edited December 1969

    Pendraia said:
    Whoa, I never thought of trying that - it would be much simpler than anything I was going to attempt. There might be problems depending on how it's implemented, but that sounds like exactly what I need. Thanks.

    Sunshine girl and I worked on a shader that would imitate the effects of iridescent silk that changes colour according to where the light is. The network we started with can be found in the DAZ wip forum in the forum archives. Sorry I don't have a link any more. We managed to come up with a network the seemed to give reasonable results.

    I'd love to see that!

  • ChoholeChohole Posts: 33,604
    edited December 1969
  • PendraiaPendraia Posts: 3,598
    edited February 2013

    Was this the thread you mean? I don't know how useful it will be, since the images of the networks aren't there.

    http://forumarchive.daz3d.com/viewtopic.php?t=155932&postdays=0&postorder=asc&start=0

    Yes...thank you both for linking to it.


    I'm not sure about your question Wancow. It's a long time since I've actually looked at the original network in that thread we did have some issues with colours not working how we expected them to. I have since created a different network which the colours reacted more how I expected them to but I'm not sure if it included the fresnel brick. I'm responding on the iPad so can't easily check either of the networks.

    To be honest I'm not sure if we were even using the fresnel brick correctly. I mainly play with bricks and see what works. The maths behind all this tends to make my brain seize up.

    We did get some interesting results though and the colours reacted to either moving the lights or if you rotated the whole scene so the lights were at a different angle.

    Hope this is making sense...I'm two weeks into a new year which means we are in assessment mode which is very full on.

    Post edited by Pendraia on
  • ps1borgps1borg Posts: 12,776
    edited December 1969

    wancow said:
    Is it possible to alter the equation associated with the 3Delight Fresnel Shader?

    You can make your own. if you know the fresnel characteristics of the material you want to simulate you can make a gradient or curve on an alpha channel that approximates the fresnel effect, use the angle of incidence as an input and pipe the output of the alpha channel to a reflect value input (graph from wikipedia) http://en.wikipedia.org/wiki/Fresnel_equations

    fresnelcurve.png
    455 x 389 - 39K
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