Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: Maya Curve node and IOR Curves

  1. #1
    Join Date
    Jan 2007
    Location
    Rhode Island
    Posts
    18

    Default Maya Curve node and IOR Curves

    I've been doing some work recently in Max and V Ray and I quite like being able to control IOR curves ala http://refractiveindex.info/ with matching curves. I came across this tutorial for achieving a similar effect, although it uses a Blinn shader. http://bct.me/tutorials/mini-cooper/. Has anyone had any success trying something similar with either the MIA or MILA materials? I realize the sliders are there for it, but I felt like I had more predictable results using actual curves.

  2. #2
    Join Date
    Dec 2005
    Location
    Wherever The Computer Says
    Posts
    2,852

    Default

    I've not actually tried this although I don't see why it wouldn't work in either.

    However, MDL allows measure data directly and is coming to 3.13 http://www.nvidia-arc.com/fileadmin/..._11Jun2014.pdf
    "Don't argue with an idiot, they will drag you down to their level and beat you over the head with experience."

  3. #3
    Join Date
    Jun 2009
    Location
    Portland, OR
    Posts
    146

    Default

    http://therenderblog.com/custom-fresnel-curves-in-maya/

    http://therenderblog.com/custom-fres...n-maya-part-2/

    Is exactly what you are looking for. Amazing work, really well done and thought out. I was able to get the gui to work for Mental Ray even though it was made for Arnold. You just have to do some code editing, but having a gui to simplify the process is invaluable. It would be awesome if someone here with more scripting ability than I could make a simple gui for this process so we don't have to hack away at the one made for Arnold...

  4. #4
    Join Date
    Jun 2009
    Location
    Portland, OR
    Posts
    146

    Default

    Also, doing it this way makes a big visual difference in believability in materials-especially in metals. You can get somewhat there with ramps connected to a sampler info node. For example with Gold you would have a gold color fade to white at grazing angle. But this adds that little touch more of accuracy without having to kill render times like what happens when reading in measured data or the old way of combining 3 different MIA materials each with their own Fresnel curves to represent the RGB values of the reflection.

  5. #5
    Join Date
    Jun 2009
    Location
    North Carolina
    Posts
    182

    Default

    Quote Originally Posted by thebeals View Post
    It would be awesome if someone here with more scripting ability than I could make a simple gui for this process so we don't have to hack away at the one made for Arnold...
    This is so awesome! I'm gonna take a look this weekend. I should be able to come up with something. I'd love to use this on a daily basis.

  6. #6
    Join Date
    Jun 2009
    Location
    North Carolina
    Posts
    182

    Default

    Well, I couldn't resist. It was too cool and only took a few minutes to fix it on up.

    I implemented the functionality into the mia_material_x and mia_material_x_passes for now. If anyone wants to see it plugged up different let me know!

    I have it plugging into reflection color.

    I made 'Effect Diffuse' do this:

    Turns on metal material
    Sets reflectivity to 1
    Turns off Fresnel
    Sets 0 degree reflections to 1

    If you want different functionality let me know. Super easy to mod that kind of stuff.

    **Edit**

    I'll make a tweak or two to the UI later on just wanted to get the quick one done ASAP!
    Attached Files Attached Files
    Last edited by JJJenkins; September 4th, 2014 at 16:55.

  7. #7
    Join Date
    Jun 2009
    Location
    Portland, OR
    Posts
    146

    Default

    You are so awesome! Much cleaner looking than the one I hacked together, thank you so much!

    In regards to having the "Metal Material" checkbox being checked.. When creating realistic materials, should this be checked? My understanding is that by having this checked, is uses the diffuse color somehow in the reflection color-maybe as a multiplier of the reflection color (refl colorXdiff color=new reflection color).

    Since pure metals have no diffuse and the color comes from the reflection color, does this mean we should leave the box unchecked and use the diffuse component as a way to add impurity to the metal rather than have it be used to affect the refl. color?

    Remydrh, what are your thoughts on this feature?

  8. #8
    Join Date
    Jun 2009
    Location
    North Carolina
    Posts
    182

    Default

    Good call! I agree with you. The reflection color will be multiplied by the diffuse and then it won't add up to 1 on the edge. We definitely want it to add up to 1 on the edge, that's part of the coolness of this set up.

    So is this what we want: metal material = off, reflectivity = 1, brdf = off, Schlick curve = 1 and 1 for 0 and 90, and reflection color = script node network.

    Should we just do away with the whole concept of 'effect diffuse' for the mia material? Seems logical to me.
    Last edited by JJJenkins; September 4th, 2014 at 19:43.

  9. #9
    Join Date
    Jun 2009
    Location
    Portland, OR
    Posts
    146

    Default

    Yea, that sounds like what I want, I agree I think we should do away with the effect diffuse concept. Thanks again!

  10. #10
    Join Date
    Jun 2009
    Location
    North Carolina
    Posts
    182

    Default

    Here's a cleaner UI with desired functionality. That dockable UI was overkill for this in my opinion so I got rid of it. I like a regular old floating window better. Let me know if anyone else would rather have it dock though. Easy enough to put it back.

    Let me know what you think!
    Attached Files Attached Files

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •